Glossary extracted starting with manual seeds, with BOW for the domain met and language EN

system element	System elements are the kinds of things or substances composing the system
gravitation	The mutual attraction between two masses of matter
condensation	The process by which water vapor undergoes a change in state from a gas to a liquid
heat balance	The equilibrium which exists on the average between the radiation received by the earth and atmosphere from the sun and that emitted by the earth and atmosphere
intertropical convergence zone	The boundary zone separating the northeast trade winds of the Northern Hemisphere from the southeast trade winds of the Southern Hemisphere.
hardwood	woods from deciduous trees that are harder than woods from coniferous trees
aob	An acronym for "At or Below".
neutron	Atomic sub-particle found in the nucleus of an atom
infrared radiation	The electromagnetic radiation with wavelengths between about 0.7 and 1000 micrometers
boiling point	The temperature at which a liquid changes to a vaporous state
molecule	Minute particle that consists of connected atoms of one or many elements.
gene frequency	Frequency of alleles at an individual or population level.
earth	The third planet from the sun and is our home.
geomagnetic pole	the point of intersection of the Earth's surface with the axis of a simple magnetic dipole that best approximates the Earth's actual, more complex magnetic field; if the Earth's magnetic field were a perfect dipole then the field lines would be vertical at the geomagnetic poles, and they would therefore coincide with the magnetic poles: however, the dipole approximation is in fact far from perfect, so in reality the magnetic and geomagnetic poles lie some distance apart.
ground water flow	Streamflow which results from precipitation that infiltrates into the soil and eventually moves through the soil to the stream channel
saturation	the condition in which the partial pressure of any fluid constituent (water in the atmospheric air) is equal to its maximum possible partial pressure under the existing environmental conditions, such that any increase in the amount of that constituent will initiate within it a change to a more condensed state; evaporation ceases under such conditions.
canopy	The layer formed naturally by the leaves and branches of trees and plants.
free radicals	Atomic or molecular species with unpaired electrons or an otherwise open shell configuration, usually very reactive
percentile	The Nth percentile is the value for which at least N percent of the data is at an equal or lesser value.
crest width	The thickness or width of a dam at the level of the crest (top) of the dam
de-icing	the removal of ice accumulation on aircraft, ships and other objects by mechanical, thermal or chemical devices.
origin	The arbitrary starting point on a graph or grid coordinate system
headwaters	Streams at the source of a river.
third law of thermodynamics	This law states if all the thermal motion of molecules (kinetic energy) could be removed, a state called absolute zero would result and all energy would be randomly distributed.
névé	Partially melted and compacted snow that has a density of at least 500 kilograms per cubic meter.
dissolution	The process of a substance dissolving and dispersing into a liquid.
pore ice	A form of periglacial ground ice that is found in the spaces that exist between particles of soil.
drainage pattern	Geometric pattern that a stream's channels take in the landscape
celestial equator	The projection of the plane of the geographical equator upon the celestial sphere.
ultramafic	Rock that is rich in magnesium and iron content.
taku	Name for a katabatic type of cold wind that occurs in Alaska.
gas hydrate	a special form of solid clathrate compound in which crystal lattice cages or chambers, consisting of host molecules, enclose guest molecules.
backscattering	Portion of solar radiation directed back into space as a result of particle scattering in the atmosphere.
threatened species	Species that is still plentiful in its natural range but is likely to become endangered because of declining population numbers.
suspensoid	a substance dispersed throughout another substance; also called suspended phase.
cation exchange capacity	The capacity of a soil to exchange cations with the soil solution
thermodynamic chart	See Fig
tornado watch	Its issued when conditions are favorable for the development of tornadoes.
wilting point	Value of soil moisture, expressed as a percentage of the mass of dry soil, below which a plant living in the soil dies by wilting.
length	The distance in the direction of flow between two specific points along a river, stream, or channel.
degree	A unit of angular measure
mercury	A metallic element of atomic weight 200.61, unique (for metals) in that it remains liquid under all but very extreme temperatures.
wave height	Vertical distance between a wave's trough and crest.
siberian express	A fierce, cold flow of air that originates in Siberia, then moves into Alaska and northern Canada before moving southward into the United States.
longwave radiation	A term used to describe the infrared energy emitted by the earth and atmosphere at wavelengths between about 5 and 25 micrometers
capo	a clamp that players place behind a fret across the strings to change the tone that the strings produce without re-tuning
ice concentration	the fraction of an area that is covered by sea ice.
snow load	the downward force on an object or structure caused by the weight of accumulated snow.
legume	Angiosperm plant species that is a member of the Fabaceae (Pea or Bean) family
celestial sphere	The apparent sphere of infinite radius having the earth as its center
heat	Heat is defined as energy in the process of being transferred from one object to another because of the temperature difference between them
alpine	refers to high mountain areas above the timber line (where trees cease to inhabit extremely cold environments).
burst	A radar term for a single pulse of radio energy.
kettle moraine	An area of glaciofluvial influenced moraine deposits pitted with kames and kettle holes.
remote sensing	The technology of acquiring data and information about an object or phenomena by a device that is not in physical contact with it
observation	a weather or meteorological observation is an evaluation of one or more meteorological elements that describes the state of the atmosphere either at the earth's surface or aloft.
ebcdic	Extended Binary Coded Decimal Interchange Code
soil texture	The relative quantities of the different types and sizes of mineral particles in a soil.
fuel moisture	The water content of fuel particle expressed as a percent of the oven dried weight of the fuel particle
detachment failure	a slope failure in which the thawed or thawing portion of the active layer detaches from the underlying frozen material.
cirrus	Wispy-looking cloud belonging to a class characterized by thin white filaments or narrow bands and a composition of ice crystals
laterization	Soil forming process that creates a laterite layer.
scintillation	Generic term for rapid variations in apparent position, brightness, or color of a distant luminous object viewed through the atmosphere.
photometer	An instrument for measuring the intensity of light or the relative intensity of a pair of lights
predation	Biological interaction between species where a predator species consumes a prey species.
eclipse	The partial or total apparent darkening of the sun when the moon comes between the sun and the Earth (solar eclipse), or the darkening of the moon when the full moon is in the Earths shadow (lunar eclipse).
spatial analysis	The examination of the spatial pattern of natural and human-made phenomena using numerical analysis and statistics.
gallery	A passageway within the body of a dam or abutment.
savart polariscope	A polariscope consisting of a specially constructed double plate polarizer and a tourmaline plate analyzer
subsidence	The slow sinking of air, usually associated with high-pressure areas.
chlorophyll	Green pigment found in plants and some bacteria used to capture the energy in light through photosynthesis.
polygonal pattern	a pattern consisting of numerous multi-sided, roughly equidimensional figures bounded by more or less straight sides.
natural selection	Environment's influence on the reproductive success of individuals in a population
varve	A thin yearly deposit of sediment found on the bottom of a lake
solar wind	Mass of ionized gas emitted to space by the Sun
mutualism	Interspecific interaction where both species experience and increase in their fitness after interacting with the other species
fabric	soil micromorphology.
ceilometer	A device using a laser or other light source to determine the height of a cloud base
mass movement	General term that describes the downslope movement of sediment, soil, and rock material.
oceanography	The study of the ocean, embracing and integrating all knowledge pertaining to the ocean's physical boundaries, the chemistry and physics of sea water, and marine biology.
pigment	Organic substance found in plant and animal cells that creates coloring.
sea level	The datum against which land elevation and sea depth are measured
ultraviolet radiation	The energy range just beyond the violet end of the visible spectrum
near infrared	Electromagnetic radiation with wavelengths from just longer than the visible (about 0.7 micrometers) to about two micrometers
bajada	Consecutive series of alluvial fans forming along the edge of a linear mountain range
tetrahedron	Silicon atom joined by four oxygen atoms (SiO4)
slope failure	The downslope movement of soil and sediment by processes of mass movement.
geodesy	A branch of applied mathematics concerned with measuring the shape of the Earth and describing variations in the Earth's gravity field.
windward	Upwind side or side directly influenced to the direction that the wind blows from
southern oscillation	Reversal of atmospheric circulation in tropical Pacific Ocean that triggers the development of an El Ni隳.
soil solution	Aqueous liquid found within a soil
volumetric water content	the ratio of the volume of the water and ice in a sample to the volume of the whole sample, expressed as a fraction (or, less commonly, as a percentage).
lateral talik	a layer or body of unfrozen ground, overlain and underlain by perennially frozen ground.
heat capacity	the amount of heat required to raise the temperature of a unit mass of a substance by one degree.
nanometer	One billionth of a meter
species diversity	Number of different species in a given region.
fossil fuel	Carbon based remains of organic matter that has been geologically transformed into coal, oil and natural gas
period decay	The tendency of a satellite to lose orbital velocity due to the influence of atmospheric drag and gravitational forces
solifluction apron	a fan-like deposit at the base of a slope, produced by solifluction.
meteor shower	An event when hundreds of meteors or shooting stars appear in the sky at a specific time.
barrier winds	Refers to the westerly flow of air along the northern slope of the Brooks Range in northern Alaska that precedes the arrival of colder air from the north.
isoline	Lines on a map joining points of equal value.
absorption	The process in which radiant energy is retained by a substance
fundamental niche	Describes the total range of environmental conditions that are suitable for a species existence without the effects of interspecific competition and predation from other species.
evaporation	Change from a liquid (more dense) to a vapor or gas (less dense) form
zodiac	The position of the sun during the course of the year as it appears to move though successive constellations
isochrone	A line on a chart connecting equal times of occurrence of an event
gauge relation	An empirical curve relating stream discharge or stage at a point on a stream to discharge or stage at one or more upstream points and, possibly, to other parameters
divergent evolution	Creation of two or more unique species from one ancestral species through the differential evolution of isolated populations.
meteor	A body of matter that enters the Earth's atmosphere from space
saturation mixing ratio	Mass of water vapor that a kilogram of dry air can hold at saturation
bioassay	A measurement of the effects of a substance on living organisms.
ukas	An acronym for United Kingdom Accreditation Service, the organization tasked by the British government with the maintenance and administration of national standards
gelisols	Soil order (type) of the United States Natural Resources Conservation Service Soil Classification System
niche glacier	very small glacier that occupies gullies and hollows on north-facing slopes (northern hemisphere); may develop into cirque glacier if conditions are favorable.
gravity	The force of attraction of the earth on an object
set	The direction towards which a current is headed
digital	Pertaining to measurements or devices in which the output varies in discrete steps, i.e
ribbon falls	Spectacular narrow waterfalls that occur at the edge of a hanging valley.
magnetosphere	Region surrounding a celestial body where its magnetic field controls the motions of charged particles
chloroplast	Organelle in a cell that contains chlorophyll and produces organic energy through photosynthesis.
soil-heat flux	The rate of flow of heat energy into, from, or through the soil.
e. coli	A group of bacteria, Escherichia, that reside in the intestinal tracts of humans and many animals and can cause food poisoning, urinary infections and enteritis.
frost-stable soil	soil in which little or no segregated ice forms during seasonal freezing.
ablation	Depletion of snow and ice by melting and evaporation.
thermohaline	In oceanography, it pertains to when both temperature and salinity act together
periglacial	the conditions, processes and landforms associated with cold, nonglacial environments.
surface impoundment	An indented area in the land's surface, such as a pit, pond, or lagoon.
reverse fault	This vertical fault develops when compressional force causes the displacement of one block of rock over another.
glacial lake	A natural impoundment of meltwater at the front of a glacier.
glaze	A smooth clear icy coating of supercooled water droplets that spread out and freeze onto objects on contact
shefpars	A software decoder for SHEF Data.
sample	A sample is a subset group of data selected from a larger population group
thaw strain	the amount that frozen ground compresses upon thawing.
optimum	The level of an abiotic factor or condition in the environment within the tolerance range at which a species or population can function most efficiently or with the greatest positive effect to its physiological or reproductive fitness.
ionosphere	A complex atmospheric zone of ionized gases that extends between 50 and 400 miles (80 to 640 kilometers) above the earth's surface
alto	A prefix to cloud-type names for clouds generally found between 3000 and 7000 meters
descending node	The point in a satellite's orbit at which it crosses the equatorial plane from north to south.
tropopause	The upper boundary zone or transition layer between the troposphere and the stratosphere
cryogenesis	the combination of thermophysical, physico-chemical and physico-mechanical processes occurring in freezing, frozen and thawing earth materials.
subsea talik	a layer or body of unfrozen ground beneath the seabottom, and forming part of the subsea permafrost.
hyphae	Thread like structures found on a fungus.
soil science	The study of soils from an interdisciplinary perspective.
ukmet	A medium-range numerical weather prediction model operated by the United Kingdom METeorological Agency.
texture	The relative quantities of the different types and sizes of mineral particles in a deposit of sediment
salinity	(1) a general property of aqueous solutions caused by the alkali, alkaline earth, and metal salts of strong acids (Cl, SO4 and NO3) that are not hydrolyzed (2) in soil science, the ratio of the weight of salt in a soil sample to the total weight of the sample.
isohel	A line drawn through geographical points having the same duration of sunshine (or other function of solar radiation) during a given interval of time.
almanac	A calendar that uses astronomical information and weather data
biodegradation	Decomposition of material by microorganisms.
orographic precipitation	Precipitation which is caused by hills or mountain ranges deflecting the moisture-laden air masses upward, causing them to cool and precipitate their moisture.
side channel spillway	A spillway whose crest is roughly parallel to the channel immediately downstream of the spillway.
adjustable emissivity	A setting on many infrared thermometers allowing you to help the thermometer calculate a more accurate temperature reading for a given material based on an estimate of its ability to emit infrared energy
thermo-erosional niche	a recess at the base of a river bank or coastal bluff, produced by thermal erosion of ice-bonded permafrost.
sorted polygon	a patterned ground form that is equidimensional in several directions, with a dominantly polygonal outline, and a sorted appearance commonly due to a border of stones surrounding a central area of finer material.
filter	Device that while selectively passing desired frequencies removes undesired ones.
basalt plateau	Extensive continental deposits of basaltic volcanic rock.
metabolism	Describes all of the enzymatic reactions performed by the cells of an organism.
seismic	Shaking displacement usually caused by an earthquake.
solifluction lobe	an isolated, tongue-shaped solifluction feature, up to 25 meters (27 yards) wide and 150 meters (164 yards) or more long; formed by more rapid solifluction on certain sections of a slope showing variations in gradient.
boyle's law	When the temperature is held constant, the pressure and density of an ideal gas are directly proportional.
ice canopy	pack ice from the point of view of the submariner.
waterfowl	Large swimming birds, like geese and ducks.
cryopeg	a layer of unfrozen ground that is perennially cryotic (forming part of the permafrost), in which freezing is prevented by freezing-point depression due to the dissolved-solids content of the pore water.
braided stream	Shallow stream channel that is subdivided into a number of continually shifting smaller channels that are separated by bar deposits.
nephelometer	An instrument which measures the scattering function of particles suspended in a medium in order to determine the visual range through the medium
context	The circumstances or setting surrounding an event or story.
thermopile	A transducer for converting thermal energy directly into electrical energy
scattering	The process by which light rays change direction of propagation through the interaction with particles, such as molecules aerosols and cloud particles.
instability	A state of atmosphere in which the vertical distribution of temperature allows rising, warm air to continue to rise and accelerate
electromagnetic radiation	Energy propagated as time-varying electric and magnetic fields
baseflow	Streamflow which results from precipitation that infiltrates into the soil and it eventually moves through the soil to the stream channel.
backing	A counterclockwise shift in the wind direction in the Northern Hemisphere at a certain location
haze	Tiny particles of dust, smoke, salt or pollution droplets that are scattered through the air
sinkhole	A pit like hole in found in areas of karst
stone garland	the downslope border of stones along a sorted step, embanking an area of relatively fine-grained bare ground upslope.
hygroscopic growth	The rate that aerosol particles grow at relative humidity values less than 100 percent.
scarification	Extensive movements of soil, sediment, and rock material caused by humans.
parasitism	Biological interaction between species where a parasite species feeds on a host species.
alkaline	Substance capable of neutralizing acid, with a pH greater than 7.0
salinity	A measure of the quantity of dissolved salts in sea water
doppler shift	The change in observed frequency of wave energy due to the relative motion of the observer and wave source
electron	A sub-particle of an atom that contains a negative atomic charge.
radiant energy	Energy in the form of electromagnetic waves and photons
thermal conductivity	the quantity of heat that will flow through a unit area of a substance in unit time under a unit temperature gradient.
attenuation	Any process in which the flux density (power) of a beam of energy is dissipated.
tropopause	The boundary zone or transition layer between the troposphere and the stratosphere
hail	Showery precipitation in the form of irregular pellets or balls of ice more than 5 mm in diameter, falling from a cumulonimbus cloud.
halo	The ring of light that seems to encircle the sun or moon when veiled by cirrus clouds
trash rack	A screen located at an intake to prevent debris from entering.
swell height	SWELL HEIGHT is defined as the vertical distance (in feet) between trough and crest of the primary swell
residual thaw layer	a layer of thawed ground between the seasonally frozen ground and the permafrost table.
captive balloon	A buoyant balloon kept from rising freely by means of a line secured to a point on the ground, as opposed to a free balloon
buttress dam	Buttress dams are comprised of reinforced masonry or stonework built against concrete
threshold	The lowest value of a measured quality at which a sensor responds
foundation pile	structure used when the soil near the ground surface is not strong and the weight of the building must be carried by deeper soil layers.
daily minimum	The lowest value (e.g
sun dog	Either of two colored luminous spots that appear at roughly 22° on both sides of the sun at the same elevation
downslope flow	Air that descends an elevated plain and consequently warms and dries
nitrogen saturation	Over abundance of nitrogen in natural ecosystems because of human induced inputs related to agriculture and fossil fuel combustion.
geocoding	The conversion of features found on an analog map into a computer-digital form
lentic system	A nonflowing or standing body of fresh water, such as a lake or pond
blow hole	opening through a snow bridge into a crevasse or system of crevasses which are otherwise sealed by snow bridges; a snowdrift usuallly forms on the lee side.
cellulose	A type of carbohydrate
thermocouple	A temperature-sensing element which converts thermal energy directly into electrical energy
snowpack	The amount of annual accumulation of snow at higher elevations.
biotic potential	Maximum rate that a population of a given species can increase in size (number of individuals) when there are no limits on growth rate.
smoke	A suspension in the air of small particles produced by combustion
light	Visible radiation (about 0.4 to 0.7 microns in wavelength) considered in terms of its luminous efficiency, that is, evaluated in proportion to its ability to stimulate the sense of sight.
chemical weathering	Breakdown of rock and minerals into small sized particles through chemical decomposition.
soil colloids	Very small organic and inorganic particles found in a soil
datastream	Similar files that are in a time-sequenced series.
pingo	A large conical mound that contains an ice core
infrared radiation	Form of electromagnetic radiation with a wavelength between 0.7 and 100 micrometers (µm)
model	A simplified representation of a physical process.
depth of snow	vertical interval between the top surface of a snow layer and the ground beneath; the layer is assumed to be evenly spread over the ground which it covers.
surface cryogenic fabric	a distinct soil micromorphology, resulting from the effects of freezing and thawing processes, in which coarser soil particles have vertical or near-vertical orientation.
vortex	A whirling mass of air in the form of a column or spiral
radiation	Emission or transfer of energy in the form of electromagnetic waves or particles.
dust	Small particles of earth or other matter suspended in the air
ice crystals	A type of precipitation composed of unbranched crystals in the form of needles, columns, or plates
pyramid of biomass	Graphic model describing the distribution of biomass in an ecosystem or community at the trophic level
sand dune	A hill or ridge of aeolian sand deposits with a minimum height of less than one meter and a maximum height of about 50 meters
head wind	A wind blowing in a direction opposite to the heading of a moving object, thus opposing the object's intended progress; the opposite of a tailwind.
precision	the degree of agreement between independent measurements of a single quantity obtained by applying a specific measurement procedure several times under prescribed conditions.
hythergraph	A type of climatic diagram whose coordinates are some form of temperature vs
spatial tradition	Academic tradition in modern Geography that investigates geographic phenomena from a strictly spatial perspective.
fermentation	Decomposition and breakdown of organic matter by anaerobic means.
heat	A form of energy transferred between two systems by virtue of a difference in temperature
coordinated universal time	(aka Greenwich Mean Time [GMT]) Local time at zero degrees longitude at the Greenwich Observatory, England
sleet	partially melted snow (or a mixture of rain and snow)
seismic wave	Successive wave-type displacement of rock usually caused by an earthquake.
thematic map	Map that displays the geographical distribution of one phenomenon or the spatial associations that occur between a few phenomena
seasonally thawed ground	ground that thaws and refreezes annually.
groundwater	Water that occupies the pore spaces found in some types of bedrock.
day	Considered a basic unit of time as defined by the earth's motion
permafrost	Zone of permanently frozen water found in high latitude soils and sediments
eosdis	See Earth Observing System Data and Information System.
hydrologic accounting	A systematic summary of the terms (inflow, outflow, and storage) of the storage equation as applied to the computation of soil-moisture changes, ground-water changes, etc
altocumulus castellanus	They are middle level convective clouds and possibly they should be classified as clouds with extensive vertical development
regional metamorphism	Large scale metamorphic modification of existing rock through the heat and pressure of plutons created at tectonic zones of subduction.
porosity	The void spaces found in rock, sediment, or soil
sand-wedge polygon	a polygon outlined by sand wedges underlying its boundaries.
calibration	The process of adjusting an instrument to be more accurate by comparing it to a reliable standard
resource	Anything obtained from the environment to meet the needs of a species.
maritime	of, relating to, or adjacent to the sea.
elevation	The measure of height with respect to a point on the earth's surface above mean sea level
isobar	A line connecting equal points of pressure.
lake talik	a layer or body of unfrozen ground occupying a depression in the permafrost table beneath a lake.
ice cake	a floe smaller than 20 meters (66 feet) across.
geothermal heat flux	the amount of heat moving steadily outward from the interior of the earth through a unit area in unit time.
nonsorted circle	a patterned ground form that is equidimensional in several directions, with a dominantly circular outline which lacks a border of stones.
lapse line	A curve showing the variation of temperature with height in the free air
figure	a distinctive pattern in wood created by its grain, annual rings, medullary and color variation
median	The value in a data set that has an equal number of values falling above and below it
polar axis	Is a line drawn through the Earth around the planet rotates
centrifugal force	The apparent force in a rotating system that deflects masses radially outward from the axis of rotation
external data	Data whose origin is not from within the ARM Program; may include data observed at ARM facilities, but whose processing and quality control is done by another program or agency and captured by ARM through the ARM External Data Center.
daily maximum	The highest value (e.g
cryoturbate	a body of earth material moved or disturbed by frost action.
control points	Horizontal and Vertical: Small monuments securely embedded in the surface of the dam
diurnal arc	The apparent arc described by heavenly bodies from their rising to their setting.
rod	A graduated staff used in determining the difference in elevation between two points
absorption	The process in which incident radiant energy is retained by a substance
entisols	Soil order (type) of the United States Natural Resources Conservation Service Soil Classification System
mineralization	Decomposition of organic matter into its inorganic elemental components.
hazard	Phenomenon which can cause loss of life, injury, disease, economic loss, or environmental damage.
thaw-sensitive permafrost	perennially frozen ground which, upon thawing, will experience significant thaw settlement and suffer loss of strength to a value significantly lower than that for similar material in an unfrozen condition.
random	Process or event that occurs by chance.
on-site meteorological services	Meteorological services provided at or near the site of a wildland fire or major project site, normally, but not necessarily, utilizing a mobile fire weather support unit
microwave radiation	Electromagnetic radiation generally in the frequency range between 300 MHz and 300 GHz (wavelengths between 1mm and 1m).
radio frequency	A frequency that is useful for radio transmission, usually between 10 kHz and 300,000 MHz.
curvature	The reciprocal of the radius of a circle; the rate of change in the deviation of a given arc from any tangent to it.
soil creep	Slow mass movement of soil downslope
repetition	Saying a word or phrase more than once, or saying it a different way so that the meaning is repeated
hi/low alarm	A feature common to thermometers that will alert you via visual and/or audible cues (or, in some cases, email or texts) when a measurement is outside user-specified limits for safety or desirability
diffraction	The result of light waves interfering with other after passing through a narrow aperture, causing them to bend or spread.
circum-pacific belt	A zone circling the edge of the Pacific Ocean basin where tectonic subduction causes the formation of volcanoes and trenches
relative humidity	A dimensionless ratio, expressed in percent, of the amount of atmospheric moisture present relative to the amount that would be present if the air were saturated
cryoplanation	the process through which cryoplanation terraces form.
isotope	Form of an element where the number of neutrons in its atomic nucleus is different than the number of protons.
tongue	a projection of the ice edge up to several km in length caused by wind and current; usually forms when a valley glacier moves very quickly into a lake or ocean.
solar constant	A term used to describe the average quantity of solar insolation received by a horizontal surface at the edge of the Earth's atmosphere
cryogenic fabric	the distinct soil micromorphology resulting from the effects of freezing and thawing processes.
spectral width	A measure of the spread of the Doppler spectrum and consequently is sensitive to the spread in the particle size spectra
reduction	In general, the transformation of data from a "raw" form to some useable form
insect	Relatively small and simple animals that have a rigid external skeleton, three body sections, three pairs of legs, and antennae
auto-off	The ability of a device to turn itself off to conserve power after a specified period of time without any user inputs
transparent	or partly or completely opaque particles or ice (hailstones) usually spheroidal, conical or irregular in form and of diameter very generally between 5 and 50 millimeters, ...
mitochondria	Organelle in a cell that oxidizes organic (see respiration) energy for use in cellular metabolism.
ph	A symbol for the degree of acidity of alkalinity of solution
caliche	An accumulation of calcium carbonate at or near the soil surface.
pressure relief pipes	Pipes used to relieve uplift or pore pressure in a dam foundation or in the dam structure.
patch	a collection of pack ice, less than 10 kilometers (6.2 miles) across, whose limits can be seen from the masthead.
uvm	An acronym for Upward Vertical Motion.
mass wasting	General term that describes the downslope movement of sediment, soil, and rock material.
maunder minimum	Period from 1645 to 1715 during which the Sun had very little sunspot activity.
dependent variable	Variable in a statistical test whose observation's values are thought to be controlled through cause and effect by another independent variable modeled in the test.
condensation	The process by which a vapor becomes a liquid
reflection	Process of returning sound or light waves back to their source.
survey mode	Refers to observational emphasis upon frequent global coverage, usually with restricted spatial and spectral resolution, aimed at developing a consistent, long-term data product for later interpretation.
equinox	The point at which the ecliptic intersects the celestial equator
mesosphere	The layer of the atmosphere located between the stratosphere and the ionosphere, where temperatures drop rapidly with increasing height
close pack ice	composed of close ice that is mostly in contact; ice cover 7/10ths to 9/10ths.
fire danger	The result of both constant factors (fuels) and variable factors (primarily weather), which affects the ignition, spread, and difficulty of control of fires and the damage they cause.
lichen	Organism that consists of a symbiotic joining of a species of fungi and a species of algae.
hydrothermal talik	a layer or body of noncryotic unfrozen ground in a permafrost area, maintained by moving groundwater.
conservation storage	Storage of water for later release for usual purposes such as municipal water supply, power, or irrigation in contrast with storage capacity used for flood control..
inversely proportional	Cause and effect relationship between two variables where a positive or negative change in the quantity of one causes a predictable opposite change in quantity in the other.
infiltration capacity	The ability of a soil to absorb surface water.
net budget	the difference between accumulation and ablation; usually expressed in terms of volumes of water equivalent per unit area.
reproducibility	The closeness of agreement among measurements of the same value of the same quantity where the individual measurements are made under different defined conditions, i.e
refraction	Changes in the direction of energy propagation as a result of density changes within the propagating medium
absolute difference	the difference, taken without regard to sign, between the values of two variables
bird	Group of warm blooded vertebrate animals whose body is covered with feathers.
protein	Organic substances primarily composed of carbon, hydrogen, nitrogen, and some other minor elements which are arranged in about 20 different compounds known as amino acids
baseline change request	A web-based tool that is used to discuss, review, and approve an "engineered product" or other changes to infrastructure components as it is turned over to ARM Operations.
sun cups	ablation hollows that develop during intense sunshine.
oxisol	Soil order (type) of the United States Natural Resources Conservation Service Soil Classification System
biological amplification	Increase in concentration of toxic fat-soluble chemicals in organisms at successively higher trophic levels of a grazing food chain or food web because of the consumption of organisms at lower trophic levels.
jetty	A structure (e.g.; a pier, or mole of wood or stone) extending into a sea, lake, or river to influence the current or tide or to protect a harbor.
probability	Statistical chance that an event will occur.
lead shore	a lead that forms between drift ice and the coast.
cation	An ion carrying a positive atomic charge.
nsf certified	This icon indicates that the design, materials, production process and quality controls used in the production of a product have been verified and certified for food safety by a highly respected third party non-profit organization, the National Sanitation Foundation (NSF).
sand sheet	Deposit of sometimes stratified less well sorted sand that almost resemble dunes
macroscale	The meteorological scale covering an area ranging from the size of a continent to the entire globe.
phase shift	The angular difference of two periodic functions.
atmosphere	The gaseous or air portion of the physical environment that encircles a planet
rom	Read Only Memory
frontogenesis	The process in which a front forms
repeatability	The closeness of agreement among a number of consecutive output values measuring the same input value under the same operating conditions, approaching from the same direction
perihelion	The point in the orbit of a planet or comet which is nearest the Sun (as opposed to the aphelion, which is the point in the orbit farthest from the Sun).
cretaceous	Geologic period that occurred roughly 65 to 144 million years ago
hydraulic conductivity	the volume of fluid passing through a unit cross section in unit time under the action of a unit hydraulic potential gradient.
dead ice	any part of a glacier which has ceased to flow; dead ice is usually covered with moraine.
albedo	The ratio of the amount of radiation reflected from an object's surface compared to the amount that strikes it
hydraulic diffusivity	the ratio of the hydraulic conductivity and the storage capacity of a groundwater aquifer.
basic solution	Any water solution that is basic (pH greater than 7) or has less hydrogen ions (H+) than hydroxide ions (OH-)
tropopause	The boundary between the troposphere and stratosphere, characterized by an abrupt change in temperature lapse rate (temperatures decrease with height in the troposphere, but it increases or remains constant with height in the stratosphere).
floodplain	Relatively flat area found alongside the stream channel that is prone to flooding and receives alluvium deposits from these inundation events.
condensation	The process by which a gas or vapor changes into a liquid.
orogenesis	The process of mountain building through tectonic forces of compression and volcanism.
net primary productivity	Total amount of chemical energy fixed by the processes of photosynthesis minus the chemical energy lost through respiration.
organelle	Is a specialized structure found in cells that carry out distinct cellular functions.
subglacial talik	a layer or body of unfrozen ground beneath a glacier in an area with permafrost.
direct flood damage	The damage done to property, structures, goods, etc., by a flood as measured by the cost of replacement and repairs.
carbohydrate	Is an organic compound composed of carbon, oxygen, and hydrogen atoms
mass	Refers to the amount of material found in an object (usually of unit volume).
producer	An organism that can synthesize the organic nutrients in requires for growth through processes like photosynthesis.
thermal diffusivity	the ratio of the thermal conductivity to the volumetric heat capacity.
coriolis force	The apparent tendency of a freely moving particle to swing to one side when its motion is referred to a set of axes that is itself rotating in space, such as Earth
nonsorted stripe	form patterned ground with a striped and nonsorted appearance, due to parallel strips of vegetation-covered ground and intervening strips of relatively bare ground, oriented down the steepest available slope.
paleosol	A soil exhibiting features that are the result of some past conditions and processes.
debris flow	a sudden and destructive variety of landslide, in which loose material on a slope, with more than 50% of particles larger than sand size, is mobilized by saturation and flows down a channel or canyon.
radiation pattern	A diagram showing the intensity of the radiation field in all directions from a transmitting radio or radar antenna at a given distance from the antenna.
algorithm	A computer program (or set of programs) which is designed to systematically solve a certain kind of problem
gleysol soil	Soil order (type) of the Canadian System of Soil Classification
pedology	The scientific study of soils.
horizon	One of several lines or planes used as reference for observation and measurement relative to a given location on the surface of the earth
beamwidth	The measure of the "width" of an antenna pattern, measured in degrees of arc
thermosyphon	a passive heat transfer device installed to remove heat from the ground.
sill	Horizontal planes of igneous rock that run parallel to the grain of the original rock deposits.They form when magma enters and cools in bedding planes found within the crust
ph	Scale used to measure the alkalinity or acidity of a substance through the determination of the concentration of hydrogen ions in solution
volcanic vent	An opening on a volcano through which lava is released and rock fragments and ash are ejected.
ultraviolet radiation	Electromagnetic radiation with a wavelength between 0.1 and 0.4 micrometers (µm).
mutation	Change in the structure of a gene or chromosome.
passive single-phase thermal pile	a foundation pile provided with a single-phase natural convection cooling system to remove heat from the ground.
cyclone	An area of low atmospheric pressure which has a closed circulation that is cyclonic (counterclockwise in northern hemisphere and clockwise in southern hemisphere).
latitudinal zonation of permafrost	the subdivision of a permafrost region into permafrost zones, based on the percentage of the area that is underlain by permafrost.
luminance	A measure of the intrinsic luminous intensity emitted by a source in a given direction
kurum	a general term for all types of coarse clastic formations on slopes of 2-3 to 40 degrees, moving downslope mainly due to creep.
anticyclone	A large-scale circulation of winds around a central region of high atmospheric pressure, clockwise in the northern hemisphere, counterclockwise in the southern hemisphere.
ripple	Stream bed deposit found streams
evaporation	The process by which a liquid changes into a gas.
dynamics	Generally, any forces that produce motion or affect change
nitrite	Form of nitrogen commonly found in the soil
gross secondary productivity	Total amount of chemical energy assimilated by consumer organisms.
cyclone	A large-scale circulation of winds around a central region of low atmospheric pressure, counterclockwise in the northern hemisphere, clockwise in the southern hemisphere.
laminates	materials in which thin sheets of wood are glued together (with each layer’s grain direction perpendicular to the last) to make a durable, rigid, composite, wooden sheets
analog forecast	An method of forecasting that uses historical weather events and wind patterns similar to the current conditions.
base flow	Rate of discharge in a stream where only the throughflow and groundwater flow from subsurface aquifers contribute to the overall flow.
algorithm	A mathematical relation between an observed quantity and a variable used in a step-by-step mathematical process to calculate a quantity.
slush	Snow or ice on the ground that has been reduced to a softy watery mixture by rain and/or warm temperatures.
convection	Motions in a fluid that transport and mix the properties of the fluid
cirrus	High-level clouds (16,000 feet or more), composed of ice crystals and appearing in the form of white, delicate filaments or white or mostly white patches or narrow bands
range gate	The discrete point in range along a single radial of radar data at which the received signal is sampled
aggradational ice	the additional ground ice formed as a direct result of permafrost aggradation.
cloud	with diameter greater than 0.5mm
air pollution	The soiling of the atmosphere by contaminants to the point that may cause injury to health, property, plant, or animal life, or prevent the use and enjoyment of the outdoors.
thaw unconformity	a boundary sometimes identified in perennially frozen ground, representing the base of a relict active layer, as well as the corresponding earlier permafrost table.
montreal protocol	Treaty signed in 1987 by 24 nations to cut the emissions of chlorofluorocarbons (CFCs) into the atmosphere
nist-traceable	Indicates that a given instrument has been calibrated using standards that have an accuracy certified by the National Institute of Standards and Technology (NIST).
point discharge	Instantaneous rate of discharge, in contrast to the mean rate for an interval of time.
ecological niche	Is all of the physical, chemical and biological conditions required by a species for survival, growth and reproduction
range	A statistical measure of the dispersion of observation values in a data set
adfreeze strength	the tensile or shear strength which has to be overcome to separate two objects that are bonded together by ice.
uniaxial compression test	a method to determine the short-term strength of rocks; conducted by employing a constant loading rate until failure; the failure load is used to calculate the failure stress; can also be used to determine the elastic constants of rocks (i.e
antarctic	Of or relating to the area around the geographic South Pole, from 90° South to the Antarctic Circle at approximately 66 1/2°South latitude, including the continent of Antarctica
quick looks	Daily and weekly plots of ARM data that give users a browsable quick view of a subset of data available at the ARM Archive.
pathogen	Microscopic parasite organism that causes disease in a host
weir	a) A low dam built across a stream to raise the upstream water level (fixed-crest weir when uncontrolled); b) A structure built across a stream or channel for the purpose of measuring flow (measuring or gauging weir).
sorted step	a patterned ground feature with a step-like form and a downslope border of stones embanking an area of relatively fine-grained bare ground upslope.
climax community	Plant community that no longer undergoes changes in species composition due to succession.
oriented lake	one of a group of lakes possessing a common, preferred, long-axis orientation.
cation exchange	Chemical trading of cations between the soil minerals and organic matter with the soil solution and plant roots.
remote sensor	Mechanical devices used to remotely sense an object or phenomenon.
organic soil	Soil order (type) of the Canadian System of Soil Classification
blind lead	a lead closed off on all sides within the ice pack.
young ice	a general category of ice that represents the transition between nilas and first-year ice; usually 10 to 30 centimeters (4 to 12 inches) thick.
exploitation	Form of competition where the indirect effects of the two or more species or individuals reduce the supply of the limiting resource or resources needed for survival.
snow grains	Precipitation of very small, white, and opaque grains of ice
attenuation	The decrease in the magnitude of current, voltage, or power of a signal in transmission between points
foreset bed	Deltaic deposit of alluvial sediment that is angled 5 to 25° from horizontal
tornado	A violently rotating column of air in contact with the ground and extending from the base of a thunderstorm
evergreen vegetation	Vegetation that keeps a majority of their leaves or needles throughout the year
luvisol soil	Soil order (type) of the Canadian System of Soil Classification
bow echo	A rapidly moving crescent shaped echo on a radar which is convex in the direction of motion
classification	Process of grouping things into categories.
karst	Landform type with limestone bedrock and dominated by geomorphic features created from solution chemical weathering.
chronologically	In the order that things happened; from first to last.
radiant energy	The energy of any type of electromagnetic radiation
bearing	The combination of antenna azimuth and elevation required to point (aim) an antenna at a spacecraft
proportional	Cause and effect relationship between two variables where a positive or negative change in the quantity of one causes a predictable similar quantity change in the other.
triple point	The point at which any three atmospheric boundaries meet
coalescence	Process where two or more falling raindrops join together into a single larger drop because of a midair collision.
transparency	The ability of a medium to allow light to pass through it.
mode	The most frequently occurring value in a data set.
convergence	Horizontal inflow of wind into an area
reptile	Group of terrestrial vertebrate animals that includes turtles, tortoises, snakes, lizards, crocodiles, and alligators.
error	the difference between a measured value of a quantity and its true value; different types of errors are inherent to observations.
two-layer permafrost	ground in which two layers of permafrost are separated by a layer of unfrozen ground.
equilibrium	Equilibrium describes the average condition of a system, as measured through one of its elements or attributes, over a specific period of time.
cryostatic pressure	Pressure exerted on a substance by ice at rest.
tolerance range	Limits of tolerance a species has to an abiotic factor or condition in the environment.
saline permafrost	permafrost in which part or all of the total water content is unfrozen because of freezing-point depression due to a high dissolved-solids content of the pore water.
lamina	thin plate, sheet or layer; laminae (plural).
recurrence interval	The average amount of time between events of a given magnitude
hysteresis	The maximum difference in output for any given input (within the specified range) when the value is approached first with increasing, and then with decreasing, input signals
a/d	Analog to Digital
aerosol	Particles of liquid or solid dispersed as a suspension in gas.
chaparral	A type of plant community common to areas of the world that have a Mediterranean climate (for example, California and Italy)
deflation	Process where wind erosion creates blowout depressions or deflation hollows by removing and transporting sediment and soil.
compensation	An addition of specific materials or devices to counteract a known error.
greenhouse effect	Process by which significant changes in the chemistry of Earths atmosphere may enhance the natural process that warms our planet and elevates temperatures
radiation	Energy emitted in the form of electromagnetic waves
isophane	A line drawn through geographical points where a given seasonal biological event occurs on the same date.
isohel	A line drawn through geographic points having equal duration of sunshine or another form of solar radiation during a specified time period.
electromotive force	The force that can alter the motion of electricity, measured in terms of the energy per unit charge imparted to electricity passing through the source of this force
symbiotic mutualism	Mutualistic interaction where the species interact physically and their relationship is biologically essential for survival.
accuracy	Degree of conformity of a measure to a standard or true value.
chemical energy	Energy consumed or produced in chemical reactions.
relict permafrost	permafrost existing in areas where permafrost can not form under present climatic conditions; reflects past climatic conditions that were colder.
snow pellets	precipitation in the form of small, white opaque ice particles; resemble ice grains, but are round (sometimes conical) and about 2-5 mm in diameter.
belt	a long area of pack ice from a few km to more than 100 kilometers in width.
solar constant	Aka total solar irradiance
layered cryostructure	the cryostructure of frozen silt or loam in which ice layers alternate with mineral layers that have a massive cryostructure.
smog	Its visible air pollution in urban areas
mass balance	The relative balance between the input and output of material within a system.
herb	A nonwoody angiosperm whose above ground vegetation dies off seasonally.
random error	The inherent imprecision of a given process of measurement, the unpredictable component of repeated independent measurements of the same object under sensibly uniform conditions.
infrastructure management board	ACRF management team that manages the overall budget, planning, user request screening, activity implementation, and impact assessments for the ARM Climate Research Facility.
humus	Dark colored semi-soluble organic substance formed from decomposition of soil organic matter.
sink	The process of providing storage for a substance
bed	Sedimentary structure that usually represents a layer of deposited sediment.
hail	precipitation of small balls or pieces of ice (hailstones) with a diameter ranging from 5 to 50 millimeters (0.2 to 2.0 inches), or sometimes bigger, falling either separately or agglomerated into irregular lumps; when the diameter is less than about 5 millimeters (0.2 inch), the balls are called ice pellets.
frets	thin metal strips (hammered into precisely spaced slots on the fingerboard) that allow players to more exactly produce specific tones.
normal distribution	A common probability distribution displayed by population data
brackish	Environment that is influenced by seawater with a salinity less than 35 parts per thousand (usually caused by the presence of an inflow of fresh water).
infrared radiation	Electromagnetic radiation lying in the wavelength interval between 0.8 micron and 1 millimeter
ultraviolet radiation	Electromagnetic radiation of shorter wavelength than visible radiation but longer than x-rays, between 0.02 and 0.4 micron (200 and 4000 angstrom).
tertiary	Geologic period that occurred roughly 1.6 to 65 million years ago
drains	A vertical well or borehole, usually downstream of impervious cores, grout curtains or cutoffs, designed to collect and direct seepage through or under a dam to reduce uplift pressure under or within a dam
thermistor	A resistor whose resistance changes with temperature
ascending node	The point in an orbit (longitude) at which a satellite crosses the equatorial plane from south to north.
dia.	Diameter
glass	In nautical terminology, a contraction for "weather glass" (a mercury barometer).
sampling	The process of obtaining a sequence of discrete digital values from a continuous sequence of analog data.
total column ozone	A measurement of ozone concentration in the atmosphere.
panchromatic	Sensitive to all or most of the visible spectrum.
condensation	Change of a substance to a denser form, such as gas to a liquid
litterfall	Movement of leaves, twigs and other forms of organic matter from the biosphere to the litter layer found in soil.
katathermometer	A type of cooling-power anemometer based upon the principle that the time constant of a thermometer is a function of its ventilation.
cirrus	High-level clouds (16,000 feet or more) composed of ice crystals and appearing in the form of white, delicate filaments or white or mostly white patches or narrow bands
binding	a thin border of plastic, wood, or other material inlaid on the outside edges at the joint between the top and sides and the joint between the back and sides of an instrument to strengthen the edges and prevent cracking, especially of softer top woods (for violin-family instruments, see purfling).
numerical forecast	The prediction of weather or climate using mathematical approximations to the equations of motion and conservation.
background extinction	Normal extinction of species that occurs as a result of changes in local environmental conditions
permafrost	layer of soil or rock, at some depth beneath the surface, in which the temperature has been continuously below 0°C for at least several years; it exists where summer heating fails to reach the base of the layer of frozen ground.
dew point	The temperature to which air must be cooled for saturation to occur, exclusive of air pressure or moisture content change
sporadic permafrost	Form of permafrost that exists as small islands of frozen ground in otherwise unfrozen soil and sediments.
conduction	The transfer of heat from one substance to another by direct contact
coriolis force	A force that deflects moving objects to one side because of the Earths rotation
ice jam	A stationary accumulation that restricts or blocks streamflow.
carrier wave	Transmitted energy which is modulated in order to carry information
volcano	An elevated area of land created from the release of lava and ejection of ash and rock fragments from and volcanic vent.
inhibition model of succession	This model of succession suggests that the change in plant species dominance over time is caused by death and small scale disturbances and variations is plant species longevity and ability to disperse
riffle	Bar deposit found on the bed of streams
solar system	The collection of celestial bodies that orbit around the Sun.
newton	The unit of force giving a mass of about one kilogram (2.205 pounds) an acceleration of about one meter (1 yard) per second per second.
stratosphere	The layer of the atmosphere above the troposphere, where temperature increases with height.
stream discharge	A river or stream's rate of flow over a particular period of time
smoke	Small particles produced by combustion that are suspended in the air
zenith	The point which is elevated 90 degrees from all points on a given observer's astronomical horizon
ecology	The study of the factors that influence the distribution and abundance of species.
genus	A group in the classification of organisms
soil moisture recharge	The process of water filling the pore space found in a soil (storage).
wave ogives	ogives that show some vertical relief on a glacier; usually the dark bands are in the hollows and the light bands are in the ridges; form at the base of steep, narrow ice falls.
thermodynamic equilibrium thickness	the thickness at which ice no longer grows because it is so thick that heat from the ocean can no longer be conducted through the ice; it may take several years of growth and melt for ice to reach an equilibrium thickness.
fixed energy	A process, like photosynthesis, where organisms repackage inorganic energy into organic energy.
circular polarized rf	Radio frequency transmissions where the wave energy is divided equally between a vertically and a horizontally-polarized component.
parasite	Consumer organism that feeds on a host for an extended period of time
precession	The comparatively slow torquing of the orbital planes of all satellites with respect to the Earth's axis, due to the bulge of the Earth at the equator which distorts the Earths gravitational field
unconformity	A break in the sequence of sedimentary strata
gross primary productivity	Total amount of chemical energy fixed by the processes of photosynthesis.
cap	Composed of a layer of warmer, dryer air aloft which may suppress or delay the development of thunderstorms
short-term strength	the failure strength of a material under a short-term loading (e.g
timber line	(1) in mountainous regions, the line above which climatic conditions do not allow the upright growth of trees (2) the poleward limit of tree growth, also known as the tree line.
design criteria	The hypothetical flood used in the sizing of the dam and the associated structures to prevent dam failure by overtopping, especially for the spillway and outlet works.
sorted net	a type of patterned ground with cells that are equidimensional in several directions, neither dominantly circular nor polygonal, with a sorted appearance commonly due to borders of stones surrounding central areas of finer material.
hardpan	Impervious layer found within the soil
lizard balloon	A balloon having a detachable tail which is released when the balloon has undergone a predetermined expansion
line-of-nodes	The line created by the intersection of the equatorial plane and the orbital plane.
acid rain	Acids form when certain atmospheric gases (primarily carbon dioxide, sulfur dioxide, and nitrogen oxides) come in contact with water in the atmosphere or on the ground and are chemically converted to acidic substances
tropical ocean-global atmosphere	TOGA is a program jointly sponsored by the United Nations World Meteorological Organization (WMO); the International Council of Scientific Unions (ICSU); the United Nations Educational, Scientific, and Cultural Organization (UNESCO) Intergovernmental Oceanographic Commission (IOC); and the ICSU Scientific Committee on Oceanic Research (SCOR)
temperature profile	the graphic or analytical expression of the variation in ground temperature with depth.
centripetal force	The force required to keep an object moving in a curved or circular path
frost heave	the upward or outward movement of the ground surface (or objects on, or in, the ground) caused by the formation of ice in the soil.
protoplasm	Substances making up a cell including its exterior membrane.
periglacial	Landforms created by processes associated with intense freeze-thaw action in an area high latitude areas or near an alpine or continental glacier.
extended forecast discussion	This discussion is issued once a day around 2 PM EST (3 PM EDT) and is primarily intended to provide insight into guidance forecasts for the 3- to 5-day forecast period
density	The ratio of the mass of a substance to the volume occupied by it.
ice jam	An accumulation of broken river ice caught in a narrow channel, frequently producing local flooding
stone earth circle	a type of nonsorted circle developed in gravelly materials.
emergency action plan	A predetermined plan of action to be taken to reduce the potential for property damage and loss of life in an area affected by a dam break or excessive spillway.
range	The values that a particular instrument is intended to measure, usually noted in a specification table by upper and lower limits.
ultisols	Soil order (type) of the United States Natural Resources Conservation Service Soil Classification System
epigenetic permafrost	permafrost that formed through lowering of the permafrost base in previously deposited sediment or other earth material.
rift	Zone between two diverging tectonic plates
universe	All of the observable phenomena in the celestial cosmos.
circadian rhythm	The cyclical changes in physiological processes and functions that are related to the 24-hour diurnal cycle.
organic cryosol	an organic soil having a surface layer containing more than 17% organic carbon by weight, with permafrost within 1 meter (3.3 feet) below the surface.
diurnal	Pertaining to actions or events that occur during a twenty-four hour cycle or recurs every twenty-four hours
recreation report	This product is used to relay reports on conditions for resorts and recreational areas and/or events
nautical mile	A unit of length used in marine navigation that is equal to a minute of arc of a great circle on a sphere
refraction	The bending of light as it passes from one medium to another.
radar	Acronym for RAdio Detection And Ranging
infiltration rate	Rate of absorption and downward movement of water into the soil layer.
inversion	A layer in the atmosphere where the temperature increases with height.
detector	A device in a radiometer that senses the presence and intensity of radiation
nasda	See Japanese National Space Development Agency.
flood plain	Lowland, bordering a river, that is usually dry, but which is subject to flooding.
icicle	Ice that forms in the shape of a narrow cone hanging point down
soil horizon	Layer within a soil profile that differs physically, biologically or chemically from layers above and/or below it.
variance	A statistical measure of the dispersion of observation values in a data set
local storm report	A product issued by local NWS offices to inform users of reports of severe and/or significant weather-related events.
paraselenic circle	A halo phenomenon consisting of a horizontal circle passing through the moon, corresponding to the parhelic circle through the sun
continental shelf break	Boundary zone between the continental shelf and slope.
eutrophic lake	Lake that has an excessive supply of nutrients, mostly in the form of nitrates and phosphates
earth sciences tradition	Academic tradition in modern Geography that investigates natural phenomena from a spatial perspective.
convergence	A contraction of a vector field; the opposite of divergence
orbiculic cryogenic fabric	a distinct soil micromorphology, resulting from the effects of freezing and thawing processes, in which coarser soil particles form circular to ellipsoidal patterns.
induction	Inference of a generalized conclusion from particular instances
radar reflectivity	A measure of the efficiency of a radar target intercepting and returning radio energy
ice storm	significant and possibly damaging accumulations of ice are expected during freezing rain situations
medial moraine	a ridge-shaped moraine in the middle of a glacier originating from a rock outcrop, nunatak, or the converging lateral moraines of two or more ice streams.
bay-mouth bar	A narrow deposit of sand and/or gravel found across the mouth of a bay.
ice storm	It is usually used to describe occasions when damaging accumulations of ice are expected during freezing rain situations
focal point	The area where weak signals collected by a satellite dish, concentrated into a smaller receiving area, converge.
mud circle	a type of nonsorted circle developed in fine-grained materials.
dynamic poisson's ratio	the absolute value of the ratio between the linear strain changes, perpendicular to and in the direction of a given uniaxial stress change, respectively, under dynamic loading conditions.
nonsorted polygon	a patterned ground form that is equidimensional in several directions, with a dominantly polygonal outline which lacks a border of stones.
nesdis	National Environmental Satellite Data and Information Service
microprocessor	A small, limited-capacity central processing unit contained entirely on one semiconductor chip.
electromagnetic wave	Method of travel for radiant energy (all energy is both particles and waves), so called because radiant energy has both magnetic and electrical properties
catastrophism	General theory that suggests that certain phenomena on the Earth are the result of catastrophic events
resonance	The state of a system in which an abnormally large vibration is produced in response to an external stimulus, occurring when the frequency of the stimulus is the same, or nearly the same, as the natural vibration frequency of the system.
ozone	A form of oxygen that has a weak chlorine odor
ion	An atom, molecule or compound that carries either a positive (cation) or negative (anion) electrical charge.
perennial snow	snow that persists on the ground year after year.
hydrocarbon	Organic compound composed primarily of hydrogen and carbon atoms
hydrostatic head	A measure of pressure at a given point in a liquid in terms of the vertical height of a column of the same liquid which would produce the same pressure.
landslide	Term used to describe the downslope movement of soil, rock, and other weathered materials because of gravity.
black carbon concentration	The concentration of carbon in its very absorbing, elemental, non-organic, non-oxide form (e.g
frost sorting	the differential movement of soil particles of different sizes as a result of frost action.
stratiform	A cloud having predominantly horizontal development.
volmet broadcast	Routine broadcast of meteorological information for aircraft in flight.
productivity	Rate of energy fixation or storage of biomass by plants
harmonics	bell-like tones that ring at frequencies that are multiples of the frequency of the fundamental note
r&d	Research and Development.
refraction	Process where insolation is redirect to a new direction of travel after entering another medium.
littoral zone	The zone along a coastline that is between the high and low-water spring tide marks.
radar	An electronic instrument, which determines the direction and distance of objects that, reflect radio energy back to the radar site
rotation	The spinning of a body, such as the earth, about its axis.
estimator	An estimator is any value calculated from the sample data For example, the sample mean is an estimator of the population mean.
dry weather flow	Streamflow which results from precipitation that infiltrates into the soil and eventually moves through the soil to the stream channel
end moraine	an arch-shaped ridge of moraine found near the end of a glacier.
snow barchan	horseshoe-shaped snowdrift, with the ends pointing down-wind.
particulate matter	Particles of dust, soot, salt, sulfate compounds, pollen, or other particles suspended in the atmosphere.
nonsorted step	a patterned ground feature with a step-like form and a downslope border of vegetation embanking an area of relatively bare ground upslope.
property protection	Measures that are undertaken usually by property owners in order to prevent, or reduce flood damage
chelate	Organic substances that cause the chemical process of chelation.
extending flow	when glacier motion is accelerating down-slope.
core	The core is a layer rich in iron and nickel found in the interior of the Earth
biodiversity	The diversity of different species (species diversity), genetic variability among individuals within each species (genetic diversity), and variety of ecosystems (ecosystem diversity)
potential energy	The energy that a body possesses by virtue of its position with respect to other bodies in the field of gravity.
single-phase thermosyphon	a passive heat transfer device, filled with either a liquid or a gas, installed to remove heat from the ground.
map scale	Ratio between the distance between two points found on a map compared to the actual distance between these points in the real world.
circle of illumination	A line that bisects areas on the Earth receiving sunlight and those areas in darkness
ampere	Standard unit to measure the strength of an electric current
value-added product	Physical models using ARM instrument data as inputs used to fulfill some of the unmet measurement needs of the ARM Program and to improve the quality of existing measurements.
conduction	Conduction consists of energy transfer directly from atom to atom and represents the flow of energy along a temperature gradient.
pollutant	A substance that has a harmful effect on the health, survival, or activities of humans or other living organisms.
freezeback	refreezing of thawed materials.
fungi	Group, at the kingdom level, in the classification of life
greenhouse effect	The heating effect of the Earth's atmosphere
periglacial processes	processes associated with frost action in cold, nonglacial environments.
liquefaction	Temporary transformation of a soil mass of soil or sediment into a fluid mass
ppm	See parts per million.
median	Statistical measure of central tendency in a set of data
slush	Its snow or ice on the ground that has been reduced to a soft, watery mixture by rain or warm temperatures.
eprom	Erasable Programmable Read Only Memory
artificial ground freeezing	the process of inducing or maintaining a frozen condition in earth materials by artificial means.
legend	A listing that contains symbols and other information about a map.
frost creep	the net downslope displacement that occurs when a soil, during a freeze-thaw cycle, expands normal (perpendicular) to the ground surface and settles in a nearly vertical direction.
law of stream lengths	Morphometric relationship observed in the cumulative size of stream segment lengths in stream channel branching
ozone	An almost colorless, gaseous form of oxygen with an odor similar to weak chlorine
flood plain	The lowland that borders a river, usually dry but subject to flooding when the river is high.
radiation	(1) emission or transfer of energy in the form of electromagnetic waves (2) the process by which electromagnetic radiation is propagated through free space by virtue of joint undulatory variations in the electric and magnetic fields in space; this concept is to be distinguished from conduction and convection.
snow grains	Frozen precipitation in the form of very small, white, opaque grains of ice
sun	Luminous star around which the Earth and other planets revolve around
heat capacity	Is the ratio of the amount of heat energy absorbed by a substance compared to its corresponding temperature rise.
second law of thermodynamics	This law states that heat can never pass spontaneously from a colder to a hotter body
apparent head capacity	the amount of heat required to raise the temperature of a unit mass of frozen ground by one degree.
pedon	A basic soil sampling unit
isodrosotherm	A line on a chart connecting points of equal dewpoint.
correlation coefficient	Statistic that measures the degree of linear association between two variables
reflector	In general, any object that reflects incident energy
heartwood	the wood at the center of a tree that no longer carrys nutrients through the tree
fold	Wavelike layers in rock strata that are the result of compression.
pleistocene	part of the geologic timescale, corresponding to the time period from 1.81 million to 11,550 years before the present.
light year	Distance that light travels in the vacuum of space in one year
salmonella	A rod-shaped bacteria common to food, particularly chicken and chicken products like eggs
discontinuity	Comparatively large contrast in meteorological elements over a relatively small distance or period of time
heliograph	An instrument which records the duration of sunshine and gives a quantitative measure of the amount of sunshine by the action of the sun's rays upon blueprint paper
thaw settlement	compression of the ground due to thaw consolidation.
dip pole	either of the two points on the earth's surface at which magnetic meridians converge; the horizontal component of the magnetic field of the earth becomes zero at this point; also called the magnetic pole.
temperature	A measure of how fast the particles in matter move.
data acquisition	The process by which events in the real world are translated into machine-readable signals.
basin	A topographic rock structure whose shape is concave downwards.
radiation	Energy transfer in the form of electromagnetic waves or particles that release energy when absorbed by an object.
discontinuous permafrost zone	the major subdivision of a permafrost region in which permafrost occurs in some areas beneath the exposed land surface, whereas other areas are free of permafrost.
epiphyte	Type of vegetation that gets its physical support from the branches of other plants
coalescence	Formation of a single water drop by the union of two or more colliding drops.
field capacity	The water remaining in a soil after the complete draining of the soil's gravitational water.
graded stream	A stream that has a long profile that is in equilibrium with the general slope of the landscape
decibel	A measure of the relative power, or of the relative values of two flux densities, especially of sound intensities and radar power densities
waders	Waist or chest high rubber (nowadays often neoprene) waterproof pants or overalls worn over other clothing.
rating curve	A graph showing the relationship between the stage, usually plotted vertically (Y-axis) and the discharge, usually plotted horizontally (X-axis).
near-real time	When referred to in textual references, the ARM conception of "near-real time" is "with a few hours delay."
sclerophyllous vegetation	Term used to describe drought resistant vegetation common in Mediterranean climates
frost creep	Slow mass movement of soil downslope that is initiated by freeze-thaw action
keystone species	Species that interacts with a large number of other species in a community
thunder	Sound created when lightning causes the rapid expansion of atmospheric gases along its strike path.
inversion	an increase in temperature with height, a reverse of the normal cooling with height
macro-scale polygons	closed, multi-sided, roughly equidimensional, patterned ground features, typically 15 to 30 meters (16 to 33 yards) across; commonly resulting from thermal contraction cracking of the ground.
roman	Real-Time Observations Monitor and Analysis Network
turning point	A temporary point whose elevation is determined by additions and subtractions of backsights and foresights respectively.
backlash	The play or loose motion in an instrument due to the clearance existing between mechanically contacting parts.
estuary	The thin zone along a coastline where freshwater systems and rivers meet and mix with a salty ocean (such as a bay, mouth of a river, salt marsh, lagoon).
vfr	Abbreviation for visual flight rules, but commonly used to refer to the relatively favorable weather and/or flight conditions to which these rules apply.
temperature	Measure of the energy in a substance
degree	A measure of temperature difference representing a single division on a temperature scale.
visible radiation	Electromagnetic radiation lying within the wavelength interval to which the human eye is sensitive, the spectral interval from approximately 0.4 to 0.7 microns (4000 to 7000 angstroms)
litter	Accumulation of leaves, twigs and other forms of organic matter on the soil surface
electricity resistivity	the property of a material that determines the electrical current flowing through a centimetre cube of the material when an electrical potential is applied to opposite faces of the cube.
bedding plane	A layer in a series of sedimentary beds that marks a change in the type of deposits.
micro-scale polygon	closed, multi-sided, roughly equidimensional, patterned ground features, less than 2 meters (6.6 feet) in diameter; usually caused by desiccation cracking of fine-grained soil materials.
telephony	Used to transmit sounds between widely removed points with or without connecting wires.
channelling	The tendency of the wind to follow the axis of a channel or be steered by sloping land, resulting in a change in its direction.
decomposer	A type of detritivore
amplitude	The magnitude of the displacement of a wave from a mean value
perihelion	The point of the earth's orbit that is nearest to the sun
glacier tongue	an extension of a glacier or ice stream projecting seaward, usually afloat.
growler	an iceberg less than 2 meters (6.6 feet) across that floats with less than 1 meter (3.3 feet) showing above water; smaller than a bergy bit.
mesotrophic lake	Lake with a moderate nutrient supply
frost boil	a small mound of soil material, presumed to have been formed by frost action.
channelization	The modification of a natural river channel; may include deepening, widening, or straightening.
nimbostratus	A cloud of the class characterized by a formless layer that is almost uniformly dark gray; a rain cloud of the layer type, of low altitude, usually below 8000 feet (2400 meters).
seasonally frozen ground	ground that freezes and thaws annually.
dry density	the mass of a unit volume of dried material (e.g
snow banner	A plume of snow blown off a mountain crest, resembling smoke blowing from a volcano.
dendrite	hexagonal ice crystals with complex and often fernlike branches.
photopolarimeter	A polarimeter utilizing a Wollaston prism as a polarizer and a Nicol prism as an analyzer.
muskeg	Poorly drained marshes or swamps found overlying permafrost.
soil fertility	The ability of a soil to provide nutrients for plant growth.
brunisol soil	Soil order (type) of the Canadian System of Soil Classification
polyarnik	Russian word for a person working for a long time at one of the polar observing stations.
leeward/lee side	the downwind side.
dis	Data and Information System
perigee	The closest distance between moon and earth or the earth and sun.
isopleth	A line connecting equal points of value
gleization	A soil formation process that occurs in poorly drained environments
longwave radiance	The rate at which light energy in the longwave portion of the spectrum is emitted in a particular direction per unit of projected surface area perpendicular to the direction of radiation.
energy flux	The rate of energy flow from, into, or through a substance.
bank	The margins of a channel
operating influence	The change in a performance characteristic caused by a change in a specified operating condition from reference operating condition, all other conditions being held within the limits of reference operating conditions.
firn	rounded, well-bonded snow that is older than one year; firn has a density greater than 550 kilograms per cubic-meter (35 pounds per cubic-foot); called névé during the first year.
soil structure	General term that describes how mineral and particles organic matter of are organized and clumped together in a soil.
niche	Adaptive role that a species has in a habitat
drift	The variation over a period of time in device output when the input parameter is fixed
video	A signal containing information on the brightness levels of different portions of an image along with information on line and frame synchronization
pedogenic regime	The particular soil forming process that operates in a certain climate
variable ceiling	Occurs when the height of a ceiling layer increases and decreases rapidly, The ascribed height is the average of all the varying values.
proxy data	Data that measures the cause and effect relationship between two variables indirectly.
galaxy	An assemblage of millions to hundreds of billions of stars.
signal conditioning	The processing of the form or mode of a signal so as to make it intelligible to, or compatible with, a given device.
general circulation model	numerical representation of the atmosphere and its phenomena over the entire earth, using the equations of motion and including radiation, photochemistry, and the transfer of heat, water vapor, and momentum.
soil moisture	Moisture contained in the soil above the water table, including water vapor which is present in the soil pores
relative permittivity	the relative permitivity of a soil is the ratio of the permitivity of the soil to the permitivity of a vacuum.
stepped leader	A faint, negatively charged channel that emerges from the base of a thunderstorm and propagates toward the ground in a series of steps of about 1 microsecond duration and 50-100 meters in length, initiating a lightning stroke.
bipolar	The ability of a panel meter to display both positive and negative readings.
pancake ice	Circular flat pieces of ice with a raised rim; the shape and rim are due to repeated collisions.
platform	Horizontal sedimentary deposits found on top of continental shield deposits.
multiple retrogressive slide	a type of mass movement associated with shear failure in unfrozen sediments underlying permafrost, leading to detachment of blocks of frozen ground that move downslope.
general circulation	of the atmosphere; complete statistical description of atmospheric motions over the earth.
pascal's law	When an external pressure is applied to any confined fluid at rest, the pressure is increased at every point in the fluid by the amount of external pressure applied
frequency division multiplexing	The combining of a number of signals to share a medium by dividing it into different frequency bands for each signal
constantan	A copper-nickel alloy used as the negative lead in Type E, Type J, and Type T thermocouples.
sensible heat	same as enthalpy; the heat absorbed or transmitted by a substance during a change of temperature which is not accompanied by a change of state; used in meteorology in contrast to latent heat.
tree	A large woody plant that has a trunk which supports branches and leaves.
data object description	The basic information, definitions, and metadata required to process "raw" measurement data to standard NetCDF files.
law of the minimum	This biological law suggests that organisms are normally limited by only one single physical factor that is in shortest supply relative to demand.
meteorology	study of the atmosphere and its phenomena, including its structure, properties, and physical processes.
freezing rain	Rain that falls in liquid form but freezes upon impact to form a coating of glaze on the ground and on exposed objects.
thaw slumping	a slope failure mechanism characterized by the melting of ground ice, and downslope sliding and flowing of the resulting debris.
moraine	A hill of glacial till deposited directly by a glacier.
virus	Is a fragment of DNA or RNA that depends on the infection of host cells for their reproduction
basic	Substance having a pH greater than 7.
instrument shelter	A boxlike structure designed to protect temperature measuring instruments from exposure to direct sunshine, precipitation, and condensation, while at the same time time providing adequate ventilation.
pseudomorph	in geology, a mineral compound resulting from a process by which the primary mineral component is replaced by another, although the compound maintains constant appearance and dimensions.
coevolution	The coordinated evolution of two or more species that interact and exert selective pressures on each other that can cause each species to undergo associated adaptations
bayhead beach	An extensive deposit of sand and/or gravel in the form of a beach at the back of a bay.
multiplexer	A device that combines several separate communications signals into one and outputs them on a sinqle line.
system relationship	Is the association that exist between the elements and attributes of a system based on cause and effect.
payload	The instruments that are accommodated on a spacecraft.
element	A molecule composed of one type of atom
topset bed	Horizontal deltaic deposit composed of coarse alluvial sediment
grassland	Ecosystem whose dominant species are various types of grass
gravity wind	A wind (or component thereof) directed down the slope of an incline and caused by greater air density near the slope than at the same levels some distance horizontally from the slope
dip	One of the directional properties of a geologic structure such as a fold or a fault
cryolithology	the study of the genesis, structure and lithology of frozen earth materials.
magnetometer	General name for an instrument which measures the earth's magnetic field intensity.
floodproofing	The process of protecting a building from flood damage on site
aurora	It is created by the radiant energy emission from the sun and its interaction with the earth's upper atmosphere over the middle and high latitudes
capillary potential	The work required to move a unit mass of water from the reference plane to any point in the soil column.
scattering	The process in which a beam of light is diffused or deflected by collisions with particles suspended in the atmosphere.
observational network	a group of stations (surface meteorological, upper-air, or other) spread over a given area for making regular observations.
cryosol soil	Soil order (type) of the Canadian System of Soil Classification
pereletok	a layer of frozen ground which forms as part of the seasonally frozen ground (in areas free of permafrost or with a lowered permafrost table); remains frozen throughout one or several summers, and then thaws.
physical weathering	Breakdown of rock and minerals into small sized particles through mechanical stress.
emissivity	The fractional amount of radiation emitted by a given object or substance in comparison to the amount emitted by a perfect emitter.
static cryosol	a mineral soil showing little or no evidence of cryoturbation, with permafrost within 1 meter (3.3 feet) below the surface.
kame	A steep conical hill composed of glaciofluvial sediments
periodic table	Table that describes some of the chemical properties of the known elements.
orographic lifting	Occurs when air is forced to rise and cool due to terrain features such as hills or mountains
range	The difference between the maximum and minimum values.
haze	The fine dry or wet dust or salt particles dispersed through a portion of the atmosphere
explosive eruption	Volcanic eruption where high-viscosity granite-rich magma causes an explosion of ash and pyroclastic material
lysimeter	A device to measure the quantity or rate of downward water movement through a block of soil usually undisturbed, or to collect such percolated water for analysis as to quality.
seawater	The mixture of water and various dissolved salts found in the world's oceans and seas.
telemetry	The transmission of data collected at a remote location over communications channels to a central station.
inceptisols	Soil order (type) of the United States Natural Resources Conservation Service Soil Classification System
seasonally thawed layer	the active layer in permafrost areas.
establishment	Subsequent growth and/or reproduction of a colonized species in a new territory.
climate	The accumulation of daily and seasonal weather events over a long period of time
altocumulus castellanus	A middle cloud with vertical development that forms from altocumulus clouds
evaporation	A process by which liquid changes into a gas or vapor.
arctic tree line	the northern limit of tree growth; the sinuous boundary between tundra and boreal forest; taken by many to delineate the actual southern boundary of the arctic zone.
mass extinction	A catastrophic, widespread perturbation where major groups of species become extinct in a relatively short time compared to normal background extinctions.
special fire weather	Meteorological services uniquely required by user agencies which cannot be provided at an NWS office during normal working hours
inlay	decorative designs made by cutting patterns into the wood of an instrument & filling the cut-out with contrasting wood, abalone, mother-of-pearl, metal or other aesthetically pleasing materials.
frost bite	frozen body tissue.
seasonally frozen layer	the active layer in areas without permafrost.
strike	One of the directional properties of a geologic structure such as a fold or a fault
invertebrate	Animal that does not have a backbone
hydrologic model	A conceptual or physically-based procedure for numerically simulating a process or processes which occur in a watershed.
solid	A state of matter where molecules where the mass of the substance does not have the property of flow.
drunken forest	trees leaning in random directions caused by melting permafrost.
energy dissipater	A structure which slows fast-moving spillway flows in order to prevent erosion of the stream channel.
granic cryogenic fabric	a distinct soil micromorphology, resulting from the effects of freezing and thawing processes, in which soil particles form discrete loosely packed units.
degree day	A unit that represents one degree of deviation from a reference point in the mean daily outdoor temperature (usually 65°F) and that is used to measure heating and cooling requirements
rms	Root Mean Square
passive two-phase thermal pile	a foundation pile provided with a two-phase natural convection cooling system to remove heat from the ground.
genetic diversity	Genetic variability found in a population of a species or all of the populations of a species
freezing rain	sleet, etc.) that present a hazard, but does not meet warning criteria.
feldspar	A group of common aluminum silicate minerals that contains potassium, sodium, or calcium.
ebris flow	A type of mass movement where there is a downslope flow of a saturated mass of soil, sediment, and rock debris.
transducer	A device which converts energy from one form into another, i.e
seed	Fertilized ovule of a plant that contains an embryo and food products for germination
genetic adaptation	Changes in the genetic makeup of organisms of a species due to mutations that allow the species to reproduce and gain a competitive advantage under changed environmental conditions.
conduction	The transfer of heat by molecular activity from one substance to another, or through a substance
solifluction sheet	a broad deposit of nonsorted, water-saturated, locally derived materials that is moving or has moved downslope.
radiation	The emission of energy from an object in the form of electromagnetic waves and photons.
phylum	A group or category used in the taxonomic and/or phylogenic classification of organisms
convergence	Wind movement that results in a horizontal net inflow of air into a particular region
population crash	Sudden decline in the number of individuals found in a population because of a scarcity of environmental resources that are required for survival, growth, and reproduction.
sandstone	A type of sedimentary rock that contains a large quantity of weathered quartz grains.
isonep	A line drawn through all points on a map having the same amount of cloudiness.
haze	Fine dry or wet particles of dust, salt, or other impurities that can concentrate in a layer next to the Earth when air is stable.
adiabatic process	A thermodynamic change of state in a system in which there is no transfer of heat or mass across the boundaries of the system
solstice	The point at which the sun is the furthest on the ecliptic from the celestial equator
ice worm	an oligochaete worm that lives on temperate glaciers or perennial snow; there are several species that range in color from yellowish-brown to reddish-brown or black; they are usually less than 1 millimeter (0.04 inch) in diameter and average about 3 millimeters (0.1 inch) long; some eat red algae.
trophic pyramid	A graphic model describing the distribution of energy, biomass, or some other measurable quantity between the different trophic levels found in an ecosystem.
fossil fuel	Any hydrocarbon deposit that can be burned for heat or power, such as petroleum, coal, and natural gas.
force	Process that changes the state of rest or motion of a body.
pole of inaccessibility	in the northern hemisphere, the point in the Arctic Ocean farthest from land; in the southern hemisphere, the point on the Antarctic continent farthest from the Southern Ocean.
photochemical smog	Photochemical smog is a condition that develops when primary pollutants (oxides of nitrogen and volatile organic compounds created from fossil fuel combustion) interact under the influence of sunlight to produce a mixture of hundreds of different and hazardous chemicals known as secondary pollutants
mass number	Total number of neutrons and protons in the nucleus of an atom
carbon cycle	Storage and cyclic movement of organic and inorganic forms of carbon between the biosphere, lithosphere, hydrosphere, and atmosphere.
evaporation	The process by which a liquid is transformed to a vapor
electrical breakdown	The sudden decrease of resistivity of a substance when the applied electric field strength rises above a certain threshold value (the substance's dielectric strength)
fill dam	Any dam constructed of excavated natural materials or of industrial wastes.
solonetzic soil	Soil order (type) of the Canadian System of Soil Classification
relative error	The ratio of the absolute error in a measurement to the size of the measurement.
ecmwf	An acronym for European Centre for Medium-Range Weather Forecasting model
strike-slip fault	Fault that primarily displays horizontal displacement.
soil taxonomy	The classification of a soil in a hierarchical system based on its various properties
general circulation models	A numerical representation of the climate system based on the physical, chemical, and biological properties of its components, their interactions, and feedback processes
nowcast	A short-term weather forecast for expected conditions in the next few hours.
sea height	SEA HEIGHT is defined as the vertical distance (in feet) between trough and crest for the average of the highest one-third of the combined windwave and swell height.
neutral	Any substance with a pH around 7.
floc	A cluster of frazil particles.
radioactive	Giving off or capable of giving off radiant energy in the form of particles or rays, as in alpha, beta, and gamma rays.
protocol	A set of rules or conventions used to standardize data transfer between devices.
inferential statistics	Statistical test that makes generalizations about a population based of the numeric information obtained from a sample based on the laws of probability.
distance to target ratio	"Indicates the diameter of the surface area an infrared thermometer will measure at a given distance
active liquid refrigerant pile	a foundation pile on which a liquid coolant refrigeration system has been installed to remove heat from the ground.
snow layer	a layer of ice crystals with similar size and shape.
heat	A form of energy transferred between systems by virtue of their temperature differences.
sea breeze	A current of air flowing inland, associated with warmer surface temperatures inland than at sea
adfreeze/adfreezing	the process by which two objects are bonded together by ice formed between them.
poisson's ratio	the absolute value of the ratio between linear strain changes, perpendicular to and in the direction of a given uniaxial stress change.
haze	A concentration of salt particles or other dry particles not readily classified as dust or other phenomenon
organ	Group of cells and tissues that have a particular function for an organism.
bit	A contraction of "binary digit." The basic element of a two-element (binary) computer language.
kelvin	A temperature scale in which 0°K is the point at which all molecular motion ceases, called absolute zero (approx
aoa	An acronym for "At or Above".
greenhouse effect	The overall warming of the earth's lower atmosphere primarily due to carbon dioxide and water vapor which permit the sun's rays to heat the earth, but then restrict some heat-energy from escaping back into space.
speciation	The process by which new species originate through mutations, natural selection, and evolution.
quartile	The 25th, 50th and 75th percentiles make up the 1st, 2nd, and 3rd quartiles, respectively.
box plot	A graph that depicts the variation and central tendency of data.
sexual reproduction	Any process of reproduction that does involve the fusion of gametes.
stratigraphy	Subdiscipline of geology that studies sequence, spacing, composition, and spatial distribution of sedimentary deposits and rocks.
magnetic field	The space influence by magnetic force
isoband cryogenic fabric	a distinct soil micromorphology, resulting from the effects of freezing and thawing processes, in which soil particles form subhorizontal layers of similar thickness.
metadata	Information describing the content or utility of a data set
ice fringe	a very narrow ice piedmont, extending less than about 1 km inland from the sea.
synchro	A motorlike device containing a rotor and a stator and capable of converting an angular position into an electrical signal, or an electrical signal into an angular position
lenticular clouds	A cloud that generally has the form of a smooth lens
drainage density	The relative density of natural drainage channels in a given area
sulfur dioxide	A gas produced from volcanic eruptions, ocean spray, organic decomposition and the burning of fossil fuels
slope failure	mass movement of earth material down a slope; includes landslides, mudslides, debris flows, avalanches, etc; speed of movement can be sudden and catastrophic or slow.
ice lense	Horizontal accumulation of permanently frozen ground ice.
freezing front	the advancing boundary between frozen (or partially frozen) ground and unfrozen ground.
bandwidth	The total range of frequency required to pass a specific modulated signal without distortion or loss of data
granoidic cryogenic fabric	a distinct soil micromorphology, resulting from the effects of freezing and thawing processes, in which soil particles form more or less discrete loosely packed units.
polygon	literally means many angled; polygons are closed, multi-sided, roughly equidimensional shapes, bounded by more or less straight sides; some of the sides may be irregular; in cryospheric science, it refers to patterned ground formations.
bowen ratio	The ratio of energy available for sensible heating to energy available for latent heating.
broadcloth	Heavy cloth, often folded double for increased durability and warmth.
sensor calibration	The relationship between input and output for a given measurement.
normal	The long-term average value of a meteorological element for a certain area
environment	The sum total of all the external conditions that effect an organism, community, material, or energy.
black ice	Thin, new ice on fresh or saltwater, appearing dark in color because of its transparency; also popularly applied to thin hazardous ice coverings on roads.
runway visual range	The maximum distance along the runway at which the runway lights are visible to a pilot at touchdown
tropopause	The upper boundary of the troposphere, usually characterized by an abrupt change in lapse rate from positive (decreasing temperature with height) to neutral or negative (temperature constant or increasing with height)
forminifera	Microscopic organisms of the group protozoa that are found living mainly in marine environments
law of stream number	Morphometric relationship observed in the number of stream segments of a particular classification order in stream channel branching
haccp	An acronym for Hazard Analysis Critical Control Point
trajectory	The curve that a body, such as a celestial object, describes in space
cryogenic aquiclude	a layer of ground which, because of its frozen state, has a low enough permeability to act as a confining bed for an aquifer.
nitrogen dioxide	A gas produced by bacterial action in the soil and by high temperature combustion
spatial isolation	Reproductive isolation of two or more populations of a species by distance or physical barriers
system	A system is a set of interrelated components working together towards some kind of process.
desiccation polygon	closed, multi-sided, patterned ground feature formed by desiccation cracks in fine-grained soil material, usually less than 2 meters (6.6 feet) in diameter.
preliminary data	Data that have not necessarily been subjected to review, quality control and/or documentation by a responsible investigator
stratosphere	Region of the atmosphere between the tropsphere and mesosphere, having a lower boundary of approximately 8 km at the poles to 15 km at the equator and an upper boundary of approximately 50 km
circuit	The complete path of an electric current; an assemblage of electronic elements; a means of two-way communication between two points - comprised of associated "go" and "return" channels.
spodosols	Soil order (type) of the United States Natural Resources Conservation Service Soil Classification System
nitrate	Form of nitrogen commonly found in the soil and used by plants for building amino acids, DNA and proteins
active air-cooled thermal pile	a foundation pile on which a cold air refrigeration system has been installed to remove heat from the ground.
nitrification	The biochemical oxidation of ammonium to nitrite and nitrite to nitrate
geoid	True shape of the Earth, which deviates from a perfect sphere because of a slight bulge at the equator.
snow pellets	Frozen precipitation in the form of white, round or conical opaque grains of ice
meridian	A circular arc that meets at the poles and connects all places of the same longitude.
primary succession	Succession on soil or sediments that do not contain an active seed bank.
air pollution	The existence in the air of substances in concentrations that are determined unacceptable to human health and the environment
emphasis	Attention or effort devoted to something to make it more noticeable or because it is important
specific heat	Is the heat capacity of a unit mass of a substance or heat needed to raise the temperature of 1 gram (g) of a substance 1 degree Celsius.
linearity	The maximum deviation of any points from a straight line drawn as a "best fit" through the calibration points of an instrument with a linear response curve
tornado alley	This is the geographic corridor in the United States which stretches north from Texas to Nebraska and Iowa
melting point	The temperature at which a solid substance undergoes fusion, i.e
latosol	Soil order (type) of the United States Natural Resources Conservation Service Soil Classification System
vector	Any quantity, such as force velocity, or acceleration, which has both magnitude and direction at each point in space, as opposed to scalar which has magnitude only
aspect ratio	The ratio of image width to image height
accuracy	"The closeness of the agreement between the result of a measurement and the value of the quantity being measured and or ""true value."" Usually expressed as Â± a certain number of degrees or Â± a certain percentage of the full reading."
geographic range	Spatial distribution of a species
afforestation	The act or process of establishing a forest, especially on land not previously forested.
radiation	The process by which energy is propagated through any medium by virtue of the wave motion of that medium
parent material	The mineral material from which a soil forms.
matter	Is the material (atoms and molecules) that constructs things on the Earth and in the Universe.
growing degree day	A form of degree day to estimate the approximate dates when a crop will be ready to harvest
bottomset bed	Horizontal deltaic deposit of alluvial sediment composed of fine silt and clay.
pedogenesis	Process of soil formation.
earthquake	A sudden, transient motion or trembling of the earth's crust, resulting from the waves in the earth caused by faulting of the rocks or by volcanic activity.
subatomic particles	Extremely small particles that make up the internal structure of atoms.
laterite	Hard subsurface deposit of oxides of aluminum and iron found in tropical soils where the water table fluctuates with seasonal changes in precipitation.
fragmic cryogenic fabric	a distinct soil micromorphology, resulting from the effects of freezing and thawing processes, in which soil particles form discrete units that are densely packed.
intangible flood damage	Estimates of the damage done by disruption of business, danger to health, shock, and loss of life and in general all costs not directly measurable which require a large element of judgment for estimating.
rs485	A protocol similar to RS232 which permits data interchange on multidrop networks of up to 32 nodes using a single twisted pair cable
delta	An alluvial deposit, often in the shape of the Greek letter "delta", which is formed where a stream drops its debris load on entering a body of quieter water.
stoplogs	Large logs, timbers or steel beams placed on top of each other with their ends held in guides on each side of a channel or conduit providing a temporary closure versus a permanent bulkhead gate.
flashboards	A length of timber, concrete, or steel placed on the crest of a spillway to raise the retention water level but which may be quickly removed in the event of a flood by a tripping device, or by deliberately designed failure of the flashboard or its supports.
spectrum	Is a graph that describes the quantity of radiation that is emitted from a body at particular wavelengths.
thermodynamics	study of the links between heat and energy
thermal talik	a layer or body of unfrozen ground (in a permafrost area) in which the temperature is above 0 degrees Celsius due to the local thermal regime of the ground.
laminar flow	Streamline flow in which successive flow particles follow similar path lines and head loss varies with velocity to the first power.
pollutant	Particles, gases, or liquid aerosols in the atmosphere which have an undesirable effect on humans or their surroundings
cyclogenesis	Process of cyclone formation, maturation, and death.
ice jam	an accumulation of broken river or sea ice caught in a narrow channel.
hip boots	Rubber boots that reach mid or upper thigh and attach to a belt that holds them up
o horizon	Topmost layer of most soils
coriolis force	A fictitious force used to account for the apparent deflection of a body in motion with respect to the earth, as seen by an observer on the earth
milky way galaxy	Aggregation of about 400 billion stars in a flattened, disk-shaped structure in space
propagule	Structure that develops into a plant.
thermal pile	a foundation pile on which natural convection or forced circulation cooling systems or devices have been installed to remove heat from the ground.
banded cryogenic fabric	a distinct soil micromorphology, resulting from the effects of freezing and thawing processes, in which soil particles form subhorizontal layers.
vernal equinox	The beginning of spring in the Northern Hemisphere
prairie	a treeless grassy plain.
ephemeris	A tabulation of a series of points that define the position and motion of a satellite
young's modulus	the ratio of increase in stress acting on a test specimen, to the resulting increase in strain, under constant transverse stress.
starch	Complex carbohydrate composed of thousands of glucose units
facsimile	A process by which graphic or photographic information is transmitted or recorded by electronic means.
carbonate	Compound consisting of a single atom of carbon and three atoms of oxygen
trade winds	easterly-blowing winds that are found on either side of the equator and blow northeasterly in the Northern Hemisphere and southeasterly in the Southern Hemisphere
conservation biology	Multidisciplinary science that deals with the conservation of genes, species, communities, and ecosystems that make up Earth's biodiversity
pumping head	Energy given to a fluid by a pump, usually expressed in feet of fluid (foot pounds per pound).
tissue	A group of similar cells that are organized into a structure with a specific purpose.
ecliptic	The sun's apparent path across the sky that tracks a circle through the celestial sphere.
newtonian telescope	A reflecting type telescope with a 45° mirror, so that the primary image is observed through a hole in the side of the tube.
parameter	(1) a term used loosely by many meteorologists for almost any meteorological quantity or element (2) an arbitrary constant or variable appearing in a mathematical expression; changing it can give various outcomes for the phenomena represented.
range	The interval between the lower and upper measuring limits of an instrument, i.e
snow flurry	snow that falls for short durations and which often changes in intensity; flurries usually produce little accumulation.
enzyme	Are types of proteins that are used to facilitate and regulate chemical reactions within cells.
nitric oxide	A gas produced by bacterial action in the soil and by high temperature combustion
thermodynamic laws	Laws that describe the physical processes, relationships, and phenomena associated with heat.
periglacial phenomena	landforms and soil characteristics produced by periglacial processes.
dielectric constant	measure of the ability of the soil to store electrical energy in the presence of an electrostatic field.
sorted stripe	patterned ground with a striped and sorted appearance, due to parallel strips of stones and intervening strips of finer material, oriented down the steepest available slope.
sugar	Type of carbohydrate chemically based on carbon, oxygen, and hydrogen.
active-layer failure	a general term referring to several forms of slope failures or failure mechanisms commonly occurring in the active layer overlying permafrost.
luminescence	Any emission of light at temperatures below that required for incandescence.
talik	An unfrozen section of ground found above, below, or within a layer of discontinuous permafrost
base	A substance that forms a salt when it reacts with acid
pulse-pair processing	Nickname for the technique of mean velocity estimation by calculation of the signal complex covariance argument
neutralism	Interspecific interaction where the species do not directly influence each other fitness.
mafic magma	Magma that is relative poor in silica but rich in calcium, magnesium, and iron content
peatland	peat-covered terrain.
palouser	A strong, dangerous, katabatic wind that descends from the mountains into the Palouse River valley in northern Idaho and eastern Washington
ldc	See less developed country.
river talik	a layer or body of unfrozen ground occupying a depression in the permafrost table beneath a river.
thaw consolidation ratio	a dimensionless ratio describing the relationship between the rate of thaw and the rate of consolidation of a thawing soil, which is considered to be a measure of the relative rates of generation and expulsion of excess water during thaw.
point bar	Stream bar deposit that is normally located on the inside of a channel bend.
ph	power of hydrogen; a measure of the activity of hydrogen ions in solution, and therefore, its acidity or alkalinity.
ozone	a nearly colorless (but faintly blue) gaseous form of oxygen, with a characteristic odor like chlorine; has a formula of O3 and a molecular weight of 48; found in trace quantities in the earth's atmosphere at all times, primarily in the stratosphere between heights of about 10 to 50 kilometers (6 to 31 miles; the ozonosphere or ozone shield) where its production results from photochemical processes involving ultraviolet radiation; its maximum concentration occurs between 20 to 25 kilometers (12 to 16 miles); in the lower atmosphere, ozone is commonly formed as a product of electrical discharges through the air.
foot-pound	A unit of energy equal to 1.356 joules.
coulomb	A unit of electrical charge which is equal to 1 ampere-second.
non-ionizing radiation	A form of electromagnetic radiation that does not have enough energy to cause ionization of atoms in living tissue
ozone	Ozone measurements are given in Dobson units and are integers with 3 significant figures
seasonal snow	(1) snow that accumulates during one season (2) snow that lasts for only one season.
coefficient of compressibility	decrease in volume per unit volume of a substance resulting from a unit increase in pressure, under isothermic conditions.
workstation	A "smart" computer terminal that serves as a primary scientific research tool, offering direct access to experimental apparatus, information files, internal computers, and output devices, usually connected to an external communications network.
scale	(1) a series of marks at regular intervals for the purpose of measuring (scale of an instrument, for example, a thermometer) (2) system of units for measuring ( 3) proportion between the size of something and the map, diagram, etc
snow worm	an oligochaete worm that lives on temperate glaciers or perennial snow; there are several species that range in color from yellowish-brown to reddish-brown or black; they are usually less than 1 millimeter (0.04 inch) in diameter and average about 3 millimeters (0.1 inch) in length; some feed off red algae.
spot size	The diameter of the circle formed by the intersection of the field of view of an infrared thermometer with the surface being measured
active-layer thickness	the thickness of the layer of the ground that is subject to annual thawing and freeing in areas underlain by permafrost.
bandpass filter	A filter whose frequencies are between given upper and lower cutoff values, while substantially attenuating all frequencies outside these values (this band).
quality-assured data	Typically, the final form of data to be submitted to the ARM data system
population parameter	A value used to represent a certain quantifiable characteristic of a population
apogee	The farthest distance between the moon and earth or the earth and sun.
mechanical strength	the failure strength of a material under given loading conditions.
probability of precipitation	PROBABILITY OF PRECIPITATION is the likelihood, expressed as a percent, of a measurable precipitation event (1/100th of an inch or more) at a grid point during the valid period.
interquartile range	the difference between the 1st and 3rd quartiles, or 25th and 75th percentiles.
sintering	the bonding together of ice crystals.
instrument data processing circuit	Data processing module that transforms data from the instrument output format into a designed data structure in netCDF format.
chromosphere	A thin layer of relatively transparent gases above the photosphere of the sun
flaw lead	a navigable passage between pack ice and fast ice.
standard deviation	Statistical measurement of the variation in a distribution: In science, standard deviation serves as measure of the spread of the data, or how likely a data point will fall close to the mean.
surcharge capacity	The volume of a reservoir between the maximum water surface elevation for which the dam is designed and the crest of an uncontrolled spillway, or the normal full-pool elevation of the reservoir with the crest gates in the normal closed position.
retreating glacier	a glacier whose terminus is increasingly retreating upvalley compared to its previous position due to a higher level of ablation compared to accumulation.
geography	The study natural and human constructed phenomena relative to a spatial dimension.
vertebrate	Animal that does have a backbone
squall line	A band of thunderstorm development found ahead of a cold front.
evaporite	Type of sedimentary rock that is formed from the concentration of dissolved salts through evaporation.
photon	A quantum (smalles unit in which waves may be emitted or absorbed) of light.
electrical conductivity	the inverse of electrical resistivity.
firewhirl	A tornado-like rotating column of fire and smoke created by intense heat from a forest fire or volcanic eruption.
ice limit	the average position of the ice edge in any given month or period based on observations over a number of years.
heat island	A dome of elevated temperatures over an urban area caused by the heat absorbed by structures and pavement.
mean	Statistical measure of central tendency in a set of data
frost phenomena	effects of frost action on earth materials and on structures placed in or on the ground.
utc	Means Coordinated Universal Time (UTC); the international time standard kept at Greenwich, England.
maximum spillway discharge	Spillway discharge (cfs) when reservoir is at maximum designed water surface elevation.
transmissometer	An electronic instrument system which provides a continuous record of the atmospheric transmission between two fixed points
sorted circle	a patterned ground form that is equidimensional in several directions, with a dominantly circular outline, and a sorted appearance commonly due to a border of stones surrounding a central area of finer material.
stream order	The relative position, or rank, of a stream channel segment in a drainage network.
data quality program	Run by the ARM Program Data Quality Office to help coordinate the continued evolution and implementation of efforts to assure the quality of the data collected by its field instrumentation.
heredity	The transmission of behavioral, physiological and morphological characteristics from parent to offspring.
peat	a deposit consisting of decayed or partially decayed humified plant remains.
halos	Rings or arcs that encircle the sun or moon
ion	Atom or molecule that has acquired an electric charge by the loss/gain of one or more electrons.
regosol soil	Soil order (type) of the Canadian System of Soil Classification
data management facility	Manages ARM datastream and provides for the collection, processing, analysis, and delivery of ARM data.
heel	the part of an instrument’s neck that widens into an L-shaped extension where the neck and body join.
polypedon	An identifiable soil with distinct characteristics found in a location or region
loess	Deposits of silt laid down by aeolian processes over extensive areas of the mid-latitudes during glacial and postglacial times.
effective porosity	The ratio, usually expressed as a percentage, of the volume of water or other liquid which a given saturated volume of rock or soil will yield under any specified hydraulic condition, to the given volume of soil or rock.
montmorillonite	A type of clay that has a large capacity to shrink and expand with wetting and drying.
rain	Precipitation in the form of liquid drops the diameter of which must be .5 millimeters or greater
flux	The rate of transfer of fluids, particles or energy per unit area across a given surface.
visibility	A measure of the opacity of the atmosphere, and therefore, the greatest distance one can see prominent objects with normal eyesight
protista	Group, at the kingdom level, in the classification of life
vapor pressure	The pressure exerted by the molecules of a given vapor
arch dam	A concrete arch dam is used in sites where the ratio of width between abutments to height is not great and where the foundation at the abutments is solid rock capable of resisting great forces
leachate	Solution containing material leached from a soil.
chaff	Small strips of metal foil, usually dropped in large quantities from aircraft or balloons
solifluction terrace	a low step, or bench, with a straight or lobate front, the latter reflecting local differences in the rate of solifluction movement.
correlation	A measure of the similarity between variables or functions.
proton	A sub-particle of an atom that contains a positive charge.
arra	American Recovery and Reinvestment Act (can also be shortened to \"Recovery Act\").
maps-net	Maryland Pilot Earth Science and Technology Education NETwork
chronograph	A clock-driven device for recording the time of occurrence of an event or the time interval between the occurrence of events.
air quality standards	The maximum level which will be permitted for a given pollutant
temperature	The measure of molecular motion or the degree of heat of a substance
carry-over	The portion of the streamflow during any month or year derived from precipitation in previous months or years.
open lead	a lead that connects two open bodies of water; ships can traverse between them through this lead; it also refers to a lead where open water is found, or a lead that has not completely frozen.
advection fog	Fog that forms as warmer, moist air moves over a cold ground
paleoclimate	Climatic conditions in the geological past reconstructed from a direct or indirect data source.
stratopause	The boundary zone or transition layer between the stratosphere and the mesosphere
density	The ratio of the mass of a substance to the volume it occupies
retrogressive thaw slump	a slope failure resulting from thawing of ice-rich permafrost.
permacrete	an artificial mixture of frozen soil materials cemented by pore ice, which forms a concrete-like construction material used in cold regions.
spirit thermometer	A liquid-in-glass thermometer which uses an organic substance such as alcohol as the thermometer liquid
frequency	Number of cycles and parts of cycles completed per second
past weather	predominant characteristic of the weather which had existed at an observing station during a given period of time (during the preceding hour or six hours), specified in the international synop code.
ice pellet	precipitation of small balls or pieces of ice (hailstones) with a diameter ranging from 5 to 50 millimeters (0.2 to 2.0 inches), or sometimes more, falling either separately or agglomerated into irregular lumps; when the diameter is less that about 5 millimeters (0.2 inch), the balls are called ice pellets.
snow	partially melting into rain on descent through a warm layer, then refreezing in a cold near-surface layer.
permafrost thickness	the vertical distance between the permafrost table and the permafrost base.
two-phase thermosyphon	a passive heat transfer device, filled with a temperature-dependent liquid/vapour combination, installed to remove heat from the ground.
isolated talik	a layer or body of unfrozen ground entirely surrounded by perennially frozen ground.
conceptual model	A simple representation, in words or figures, of a complex process or idea.
wave	An identifiable, periodic disturbance or motion in a medium that shows displacement
rain	Acid Precipitation- Rain or snow with a pH value of less than 5.6
plantae	Group, at the kingdom level, in the classification of life
seed bank	Collection of seeds available for germination in the soil.
eclipse	The obscuring of one celestial body by another.
thawing front	the advancing boundary between thawed ground and frozen ground.
pulse radar	A type of radar, designed to facilitate range (distance) measurements, in which are transmitted energy emitted in periodic, brief transmission.
calorie	Quantity of energy
ionizing radiation	The emission of alpha or beta particles or gamma rays from radioisotopes
solar eclipse	An eclipse of the sun occurs when the moon is in a direct line between the sun and the earth, casting some of the earth's surface in its shadow
hail	A mixture of liquid and frozen precipitation
self-regulation	The ability of some systems to maintain a steady state equilibrium through positive and negative feedbacks.
meander belt	The area between lines drawn tangential to the extreme limits of fully developed meanders.
precipitate	Solidification of a previously dissolved substance from a solution.
condensation	The process by which water changes phase from a vapor to a liquid.
inland freshwater wetlands	Swamps, marshes, and bogs found inland beyond the coastal saltwater wetlands.
cryostructure	the structural characteristics of frozen earth materials.
law of basin areas	Morphometric relationship observed in the mean basin area size of stream segments of a particular classification order in stream channel branching
recession constant	Constant used to reduce the API value daily in the API method of estimating runoff.
ground clutter	A pattern of radar echoes from stationary objects like buildings near the radar site
ablation area	the area of a glacier where more glacier mass is lost than gained.
space environment monitor	Instrument that measures the condition of the Earth's magnetic field and the solar activity and radiation around the spacecraft, and transmits these data to a central processing facility
snow	Deposits of dew, fog, and frost are excluded.
ice-wedge polygon	a polygon outlined by ice wedges underlying its boundaries.
atoll	A coral island consisting of a ring of coral surrounding a central lagoon
meteor	Its a shooting star
loam	A soil that contains a roughly equal mixture of clay, sand, and silt
conglomeric cryogenic fabric	a distinct soil micromorphology, resulting from the effects of freezing and thawing processes, in which coarser soil particles form compound arrangements.
aphelion	The point on the earth's orbit that is farthest from the sun
ozone	A nearly colorless gas and a form of oxygen (O2)
open pack ice	composed of floes seldom in contact and with many leads; ice cover 4/10ths to 6/10ths.
grout curtain	A barrier produced by injecting grout into a vertical zone, usually narrow (horizontally), and in the foundation to reduce seepage under a dam.
equilibrium line	boundary between the accumulation area and ablation area where the mass balance is zero.
talik	a layer or body of unfrozen ground occurring in a permafrost area due to a local anomaly in thermal, hydrological, hydrogeological, or hydrochemical conditions.
upward freezing	the advance of a freezing front upwards from the permafrost table during annual freezing of the active layer.
dbm	A logarithmic expression for power, referenced to 1 milliwatt
action	the distance between the strings and fingerboard or frets; excessively high action makes the strings hard to press; excessively low action causes buzzing.
actual evapotranspiration	The rate of water lost from vegetation and soil, ordinarily at a slower rate than the potential rate.
narrative	A story.
carbon-film hygrometer element	An electrical hygrometer element constructed of a plastic strip coated with a film of carbon black dispersed in a hygroscopic binder
townsend support	A fixed support for mounting maximum and minimum thermometers of the liquid-in-glass type
phase change	Reorganization of a substance at the atomic or molecular level resulting in a change of the physical state of matter
soil organic matter	Organic constituents of soil.
bookmatch	a method of cutting a single piece of wood through its thickness to make two pieces that have mirror-image grain pattern
rotation	Process of the Earth turning on its axis
drumlin	A hill shaped deposit of till
halite	Sedimentary rock created by the chemical precipitation of sodium and chlorine.
ph	A measure of the acidity or alkalinity of a substance, using numerical values from 0 (maximum acidity) through 7 (neutral) to 14 (maximum alkalinity).
perigee	The point nearest the earth on the moon's orbit
island arc	A line of volcanic islands found of the ocean that have been created by the convergence of two tectonic plates and the subsequent subduction of one of the plates beneath the other
soil wedge	a wedge-shaped body of soil that is different in structure and texture from the surrounding soil.
operating conditions	Conditions to which a device is subjected, not including the variable measured by the device
cryoturbation	(1) (singular) a collective term used to describe all soil movements due to frost action (2) (plural) irregular structures formed in earth materials by deep frost penetration and frost action processes, and characterized by folded, broken and dislocated beds and lenses of unconsolidated deposits, included organic horizons and even bedrock.
nuclear energy	Energy released when the nucleus of an atom experiences a nuclear reaction like the spontaneous emission of radioactivity, nuclear fission, or nuclear fusion.
thaw weakening	the reduction in shear strength due to the decrease in effective stresses resulting from the generation and slow dissipation of excess pore pressures when frozen soils containing ice are thawing.
frost heave extent	the difference between the elevations of the ground surface before and after the occurrence of frost heave.
independent variable	Variable in a statistical test that is thought to be controlling through cause and effect the value of observations in another dependent variable modeled in the test.
infrared	The long wave, electromagnetic radiation of radiant heat emitted by all hot objects
salinity	Concentration of dissolved salts found in a sample of water
diurnal	Means daily, especially pertaining to actions which are completed in 24 hours and are repeated every 24 hours.
nonlinear	Not a linear function of the relevant variables.
switching power supply	A power supply which achieves its output regulation by means of one or more active power handling devices which are alternately placed in the "off" or "on" states
infrared	A type of thermometry that measures the amount of infrared energy being emitted by a substance and compares that value to a predictable curve to calculate temperature.
klystron	An electron tube used as a low-power oscillator or a high-power amplifier at ultrahigh frequencies
data archive	Serves as long-term storage for ARM data to keep data easily accessible
podzolization	Soil forming process that produces a strongly leached soil with a distinctive iron hardpan layer in the B horizon
accumulation zone	area of a glacier where more mass is gained than lost.
rangeland	Land-use type that supplies vegetation for consumption by grazing and browsing animals
atmosphere	A layer of gases surrounding a planet
heterotroph	Organism that must consume energy rich organic molecules for survival
stratiform	Descriptive of clouds of extensive horizontal development, as contrasted to the more narrow and vertically developed cumuliform type
standard error	The standard deviation (positive square-root of the variation) of the errors associated with physical measurements of an unknown quantity, or statistical estimates of an unknown parameter or of a random variable.
fiducial point	A point (or line) on a scale used for reference or comparison purposes
air mass	A body of air covering a relatively wide area and exhibiting horizontally uniform properties.
community	Refers to all the populations of interacting species found in a specific area or region at a certain time.
theta-e ridge	An axis of relatively high values of theta-e
absolute zero	Considered to be the point at which theoretically no molecular activity exists or the temperature at which the volume of a perfect gas vanishes
histosols	Soil order (type) of the United States Natural Resources Conservation Service Soil Classification System
x-rays	Very energetic electromagnetic radiation with wavelengths intermediate between 0.01 and 10 nanometers (0.1-100 Angstroms) or between gamma rays and ultraviolet radiation
radiation shield	A device used on certain types of instruments to prevent unwanted radiation from affecting the measurement of a quantity
dovetail	an interlocking joint that combines a flaring tenon and a mortise into which it tightly fits– the neck joints on Martin’s Standard Series guitars are dovetail joints.
equinox	either of the two points of intersection of the sun's apparent annual path and the plane of the earth's equator; in the northern hemisphere the spring (vernal) equinox falls on or about 21 March, and the autumnal equinox on or about 22 September.
nadir	The point on any given observer's celestial sphere diametrically opposite of one's zenith.
cape verde islands	A group of volcanic islands in the eastern Atlantic Ocean off the coast of West Africa
observational error	The difference between the true value of some quantity and its observed value
mycorrhizae	Mutualistic association of a fungus with the root of higher plant
accumulation area	area of a glacier where more mass is gained than lost.
solum	Part of the soil that is capable of supporting life.
chemical process	(chemistry) any process determined by the atomic and molecular composition and structure of the substances involved
inactive storage capacity	The portion of capacity below which the reservoir is not normally drawn, and which is provided for sedimentation, recreation, fish and wildlife, aesthetic reasons, or for the creation of a minimum controlled operational or power head in compliance with operating agreements or restrictions.
polar explorer	a person working for a long time at one of the polar observing stations; Russian word is polyarnik.
collapse scar	that portion of a peatland where the whole or part of a palsa or peat plateau has thawed and collapsed to the level of the surrounding peatland.
gulf	A large arm of an ocean or sea extending into a land mass.
apogee	The point farthest from the earth on the moon's orbit
sunspot	dark spot on the sun, with cooler-than-average temperatures and strong magnetic activity
potential energy	Is the energy that a body possesses by virtue of its position and that is potentially transformable into another form of energy.
field	The set of influences (electricity, magnetism, gravity) that extend throughout space.
ice skylight	from the point of view of the submariner, thin places in the ice canopy, usually less than 1 meter (3.3 feet) thick and appearing from below as relatively light, translucent patches in dark surroundings; the under-surface of an ice skylight is normally flat; ice skylights are called large if big enough for a submarine to attempt to surface through them (120 meters, 131 yards), or small if not.
monera	Group, at the kingdom level, in the classification of life
parhelion	Either of two colored luminous spots that appear at points 22° (or somewhat more) on both sides of the sun and at the same elevation as the sun
shear strength	in geology, describes the compressive strength (ability to withstand pushing forces) of soils; results from two internal mechanisms: cohesion between soil particles, and friction caused by contact between particles; variable among different soils.
troposphere	Layer in the atmosphere found from the surface to a height of between 8 to 16 kilometers of altitude (average height 11 kilometers)
altitudinal zonation of permafrost	the vertical subdivision of an area of mountain permafrost into permafrost zones, based on the proportion of the ground that is perennially cryotic.
phenolic	A plastic molding component formed by the reaction of phenol and formaldehyde
prokaryote	Organisms whose cells have their genetic material in the form of loose strands of DNA found in the cytoplasm
culmination	The point at which a satellite reaches its highest position or elevation in the sky, relative to an observer (aka the closest point of approach).
system state	Current value of a system's elements, attributes, and/or relationships.
bracing	supportive wooden struts that strengthen instruments and affect tone; violin-family instruments have a single brace called a, “tone bar” that lies under the bass foot of the bridge; mandolins and guitars have various patterns of struts depending on the structure of the instrument, the kind of strings the instrument supports and the kind of tone that the builder tries to achieve
amplitude modulation	One of three ways to modify a sine wave signal in order to make it "carry" information
inclination	One of the six Keplerian elements, it indicates the angle of the orbit plane to the central body's equator.
modem	Device that allows two computers (which use binary data in the form of bits) to communicate using a telephone line (which uses tones)
fertilizer	Substance that adds inorganic or organic nutrients to soil for the purpose of increasing the growth of crops, trees, or other vegetation.
standard deviation	A statistical measure of the dispersion of observation values in a data set
ansi	An acronym for American National Standards Institute
neutral solution	Any water solution that is neutral (pH approximately 7) or has an equal quantity of hydrogen ions (H+) than hydroxide ions (OH-)
convection	Convection involves the transfer of heat energy by means of vertical mass motions through a medium.
external instruments	Instruments that belong to organizations that are outside of the ARM Program.
dds	Data Distribution System.
cumulus	A form of cloud consisting of rounded masses heaped on horizontal base.
veering	A clockwise shift in the wind direction in the Northern Hemisphere at a certain location
staphylococcus	A microscopic bacteria common to skin and mucous membranes
logarithm	Exponent of the power to which it is necessary to raise a fixed number (the base) to produce the given number
melting point	The temperature at which a solid substance undergoes fusion, changing from a solid to a liquid state
permafrost boundary	(1) the geographical boundary between the continuous and discontinuous permafrost zones (2) the margin of a discrete body of permafrost.
satellite revolution	The time from one perigee (the point of an elliptical orbit path where a satellite is closest to Earth) to the next.
big crunch	Collapse of the Universe into its original form before the Big Bang
u.s. geological survey	The Federal Agency chartered in 1879 by congress to classify public lands, and to examine the geologic structure, mineral resources, and products of the national domain
dynamic modulus of elasticity	the ratio of stress to strain for a material under dynamic loading conditions.
mode	Statistical measure of central tendency in a set of data
viscosity	a measure of a fluid's resistance to flow; can be thought of as a measure of fluid friction.
crust-like cryostructure	the cryostructure of a frozen deposit of angular blocks that are coated with ice, whereas large spaces between the blocks are not filled with ice.
haze	Fine dust or salt particles dispersed through a portion of the atmosphere; a type of lithometer
planetary permafrost	permafrost occurring on other planetary bodies (planets, moons, asteroids).
siphon spillway	A spillway with one or more siphons built at crest level
isoheight	Same as a contour depicting vertical height of some surface above a datum plane.
stratosphere	The layer of the atmosphere above the troposphere and below the mesosphere (between 10 km and 50 km), generally characterized by an increase in temperature with height.
downdraft	A column of cool air that sinks toward the ground
latent heat	The energy released or absorbed during a change of state.
conductor	Any substance or object which carries electricity.
mass balance	the difference between accumulation and ablation on a glacier; usually calculated on an annual basis.
kinetic energy	The energy due to motion.
marginal crevasse	a crevasse near the side of a glacier formed as the glacier moves past stationary valley walls; usually oriented about 45 degrees up-glacier from the side wall.
star	A large and very massive, self-luminous celestial body of gas that illuminates via the radiation derived from its internal source of energy.
rainwash	The erosion of soil by overland flow
convergence	An atmospheric condition that exists when the winds cause a horizontal net inflow of air into a specified region.
transient talik	a layer or body of unfrozen ground (in a permafrost area) that is gradually being eliminated by freezing.
ecosystem	An ecosystem is a system where populations of species group together into communities and interact with each other and the abiotic environment.
ozone hole	A large area of intense stratospheric ozone depletion over the Antarctic continent that typically occurs annually between late August and early October, and generally ends in mid-November
dalton's law	States that the total pressure exerted by a mixture of gases is equal to the sum of the partial pressures of the gases
carrying capacity	The steady-state density of a given species that a particular habitat can support.
absolute error	the difference between the measured or inferred value of a quantity and its actual value.
hydrochemical talik	a layer or body of cryotic (but unfrozen) ground in a permafrost area, maintained by moving mineralized groundwater.
total carbon	The total concentration of carbon in all its organic and non-organic forms.
endangered species	A species found in nature that has so few surviving individuals that the it could soon become extinct in all or most of its natural range
snow line	Altitudinal or latitudinal limit separating zones where snow does not melt during the summer season from areas in which it does
electroscope	A general name for instruments which detect the presence of (but do not necessarily measure) small electrical charges by electrostatic means
coronagraph	An instrument for photographing the corona and prominences of the sun at times other than at solar eclipse.
earthflow	A rapid type of downslope mass movement that involves soil and other loose sediments
secondary substance	Organic chemical produced by a plant that has no direct function in its metabolism
gradient	The time rate or spatial rate of change of an atmospheric property.
electromagnetic radiation	Also called radiation, it is waves of energy propagated though space or through a material media.
fitness	A measure of the health of a species in terms of physiology and future reproductive success.
cirque glacier	glacier that resides in basins or amphitheaters near ridge crests; most cirque glaciers have a characteristic circular shape, with their width as wide or wider than their length.
continuous permafrost	Form of permafrost that exists across a landscape as an unbroken layer.
entropy	Entropy is the measure of the disorder or randomness of energy and matter in a system.
bridge	the part of an acoustic instrument that transmits vibration from the strings to the top of the instrument; the bridge can be attached to the soundboard with glue or held against the soundboard by the tension of the strings that pass over it
predator	Consumer organism who feeds on prey
crystal habit	The size and shape of the crystals in a crystalline solid
el ni隳	Name given to the occasional development of warm ocean surface waters along the coast of Ecuador and Peru
ozone layer	An atmospheric layer that contains a high proportion of oxygen that exists as ozone
snow pellets	Precipitation of white, opaque grains of ice
conduction	The transfer of heat through a substance by molecular action or from one substance by being in contact with another.
parapet wall	A solid wall built along the top of the dam for ornament, safety, or to prevent overtopping.
chromosome	Organic structure that carries an organism's genetic code (DNA).
diversity	See Species Diversity.
firmware	Programs or instructions which are stored in read-only memory.
color temperature	An estimate of the temperature of an incandescent body, determined by observing the wavelength at which it is emitting with peak intensity (its color) and using that wavelength in Wien's law.
personal experience narrative	An account of a personal experience told in first-person.
soil permeability	The rate at which water and air move vertically through a soil.
tornado alley	A geographic corridor in the United States which stretches north from Texas to Nebraska and Iowa
upslope effect	The cooling of an air flow as it ascends a hill or mountain slope
creep of frozen ground	the slow deformation (or time-dependent shear strain) that results from long-term application of a stress too small to produce failure in the frozen material.
taxon	A classification category for a group of organisms.
cryosol	soil formed in either mineral or organic materials having permafrost either within 1 meter (3.3 feet) below the surface or, if the soil is strongly cryoturbated, within 2 meters (6.6 feet) below the surface, and having a mean annual ground temperature below 0 degrees Celsius.
kilohertz	One thousand hertz, i.e., one thousand cycles per second.
specific heat capacity	the amount of heat required to raise the temperature of a unit mass of a substance by one degree.
gravimetric water content	the ratio of the mass of the water and ice in a sample to the dry mass of the sample, commonly expressed as a percentage.
elevation	The angle at which an antenna must be pointed above the horizon for optimal reception from a spacecraft.
condensation	The change in state of matter from vapor to liquid that occurs with cooling
thermodynamics	Study of the processes that involve the transformation of heat into mechanical work, of mechanical work into heat, or the flow of heat from a hotter body to a colder body.
electromagnetic wave	an oscillation of the electric or magnetic field associated with the propagation of energy; characterized by their wavelengths and amplitude; propagate at the speed of light.
freezing rain	rain falling in a liquid form through a shallow below-freezing layer of air near the ground
microwave	Electromagnetic radiation with wavelengths between about 1000 micrometers and one meter
isotropic	A line of constant equal physical properties along all axes.
model	A mathematical representation of a process, system, or object developed to understand its behavior or to make predictions
detritus food chain	Model describing the conversion of organic energy in a community or ecosystem into inorganic elements and compounds through decomposition
ozone hole	Is a sharp seasonal decrease in stratospheric ozone concentration that occurs over Antarctica in the spring
absorption	The process in which incident radiant energy is retained by a substance by conversion to some other form of energy.
ecotone	Boundary zone between two unique community types.
compound	A compound is the atoms of different elements joined together.
integrated circuit	A solid state electronic circuit that consists of several micro-components constructed to perform a special function.
ozone	Tri-atomic oxygen that exists in the Earth's atmosphere as a gas
weather	The state of the atmosphere, mainly with respect to its effects upon life and human activities
downslope effect	The warming of an air flow as it descends a hill or mountain slope.
perihelion	It is the point in the Earth's orbit when it is closest to the Sun (147.5 million km)
moist adiabat	The line on a Skew T-Log P chart that depicts the change in temperature of saturated air as it rises and undergoes cooling due to adiabatic expansion
glacier	A large long lasting accumulation of snow and ice that develops on land
rock cycle	General model describing the geomorphic and geologic processes involved in the creation, modification and recycling of rocks.
mollisols	Soil order (type) of the United States Natural Resources Conservation Service Soil Classification System
frost jacking	cumulative upward displacement of objects embedded in the ground, caused by frost action.
tide	The regular rise and fall of the Earth's oceans caused by the actions of the moon's and sun's gravitation acting on the rotating Earth.
map	An abstraction of the real world that is used to depict, analyze, store, and communicate spatially organized information about physical and cultural phenomena.
fram strait	a sea channel connecting the Arctic Ocean and the Nordic Seas, running between Greenland and Spitsbergen
clear	To restore a device to a its initial state, usually the zero state.
fog	A large mass of water vapor cooled to fine particles.
gene pool	Sum total of all the genes found in the individuals of the population of a particular species.
radioactive decay	Natural decay of the nucleus of an atom where alpha or beta particle and/or gamma rays are released at a fixed rate.
volatilization	The process where a solid or liquid substance is converted into a gas.
fen	A habitat composed of woodland and swamp.
runway visibility	The visibility along an identified runway, determined from a specified point on the runway with the observer facing in the same direction as a pilot using the runway
conduction	the transport of energy entirely resulting from the random motions of individual molecules, and not from any concerted group movement; occurs in response to temperature gradients; contrasts with convection, in which energy is transported by molecules moving together in coherent groups.
infiltration capacity	The maximum rate at which precipitation can pass through the surface into the soil, for a given soil in a given condition.
bathymetric chart	A map delineating the form of the bottom of a body of water, usually by means of depth contours (see Isobaths).
computer	Electronic machine capable of performing calculations and other manipulations of various types of data, under the control of a stored set of instructions
natural ionizing radiation	Ionizing radiation that comes from natural sources in the environment.
fluid	Substance, gas or liquid, that has the property of flow.
fragmoidal cryogenic fabric	a distinct soil micromorphology, resulting from the effects of freezing and thawing processes, in which soil particles form discrete units that are coalescing.
prime meridian	the meridian (line of longitude) defined to be 0 degrees and passing through the Royal Greenwich Observatory in London; also known as the International Meridian or Greenwich Meridian; the Prime Meridian and the opposite 180th meridian (at 180 degrees longitude) separate the Eastern and Western Hemispheres.
ice crystals	A barely visible crystalline form of ice that has the shape of needles, columns or plates
hydrologic equation	The water inventory equation (Inflow = Outflow + Change in Storage) which expresses the basic principle that during a given time interval the total inflow to an area must equal the total outflow plus the net change in storage.
ram	Random Access Memory
hertz	An international unit of frequency equal to one cycle per second, and named after a German physicist.
glacial drift	A generic term applied to all glacial and glaciofluvial deposits.
earthlight	The faint illumination of the dark part of the moon's disk produced by sunlight reflected onto the moon from the earth's surface and atmosphere.
emissivity	the amount of electromagnetic energy (primarily at wavelengths longer than 1.0 micrometer) that an object emits; for example, the earth emits longwave radiation primarily in the infrared part of the electromagnetic spectrum, but also in longer microwave wavelengths; the emissivity of an object varies as the fourth power of its absolute temperature.
elastic wave	An energy wave that causes elastic deformation in a material without its structure and shape being deformed.
mole	A unit of mass numerically equal to the molecular weight of the substance
construction methods in permafrost	special design and construction procedures required when engineering works are undertaken in permafrost areas.