grayThe special name for the unit that expresses a measure of absorbed dose. One gray corresponds to an energy deposition of one joule per kg of living tissue.
Gray waterWastewater other than sewage, such as sink and bath drainage or washing machine discharge.
GraybodyA hypothetical "body" that absorbs some constant fraction of all electromagnetic radiation incident upon it.
GrazingConsumption of native forage from rangelands or pastures by livestock or wildlife.
Grazing allotmentAn area where one or more livestock operators graze their livestock. An allotment generally consists of federal land but may include parcels of private or…
Grazing leaseAn authorization that permits the grazing of livestock on public lands outside the grazing districts during a specified period of time (Section 15 of the…
Great BasinAn area covering most of Nevada and much of western Utah, as well as portions of southern Oregon and southeastern California, consisting primarily of…
Great Circle TrackA great-circle track is the shortest distance between two points on a sphere, and when viewed on a 2-dimensional map the track will appear curved.
Great Lakes FaxbackDissemination systems housed at Weather Forecast Office (WFO) Cleveland by which Great Lakes customers request and receive hard copies of selected marine…
Great Lakes Freeze-Up/Break-Up Outlook(FBO) - A National Weather Service product to keep mariners informed of the projected freeze-up date or break-up date of ice on the Great Lakes.
Great Lakes Storm Summary(GLS) - A National Weather Service forecast product providing updated information whenever a storm warning is in effect on any of the Great Lakes.
Great Lakes Weather Broadcast(LAWEB) - A National Weather Service product containing an observation summary prepared to provide Great Lakes mariners with a listing of weather…
Green Building or Green DesignBuilding design that yields environmental benefits, such as savings in energy, building materials, and water consumption, or reduced waste generation.
Green CertificatesGreen certificates represent the environmental attributes of power produced from renewable resources.
Green Fluorescent Protein(Abbreviation: GFP). A protein derived from a species of jelly fish, that fluoresces when exposed to ultra violet light.
Green LineThe green line is one of the strongest (and first-recognized) visible coronal lines. It identifies moderate temperature regions of the CORONA.
Green loggingThe logging of timber that is still alive.
Green PowerA popular term for energy produced from clean, renewable energy resources.
Green PricingA practice engaged in by some regulated utilities (i.e. power providers) where electricity produced from clean, renewable resources is sold at a higher…
Green revolutionAdvances in genetics, petrochemicals, and machinery that culminated in a dramatic increase in crop productivity during the third quarter of the 20th…
Green ton2,000 pounds of undried biomass material. Moisture content must be specified if green tons are used as a measure of fuel energy.
GreenfieldsNewly developed commercial real estate on what was previously undeveloped open space.
Greenhouse EffectA popular term used to describe the heating effect due to the trapping of long wave (length) radiation by greenhouse gases produced from natural and human…
Greenhouse GasSome greenhouse gases, which contribute to the greenhouse effect, occur naturally in the atmosphere while others result from human activities such as the…
Greenhouse Gas (GHG)Any gas that absorbs infrared radiation in the atmosphere. Greenhouse gases include, but are not limited to, water vapor, carbon dioxide (CO2), methane…
Greenhouse gase (GHG)Heat-trapping gases that cause global warming. Natural and human-made greenhouse gases include water vapor, carbon dioxide, methane, nitrogen oxides…
Greenhouse GasesThose gases, such as water vapor, carbon dioxide, tropospheric ozone, methane, and low level ozone that are transparent to solar radiation, but opaque to…
Greenland HighGreenland High The anticyclone that appears to overlie Greenland; analogous to the Antarctic anticyclone.
GreenwayA linear open space; a corridor composed of natural vegetation. Greenways can be used to create connected networks of open space that include traditional…
Greenwich Mean Time (GMT)Same as Coordinated Universal Time (UTC); the international time standard kept at Greenwich, England.
GreywaterWaste water from a household source other than a toilet. This water can be used for landscape irrigation depending upon the source of the greywater.
GRIB(Gridded Binary Format) - A format used for meteorological data. Typically used in the past for computer generated model data but will be used…
GridA common term referring to an electricity transmission and distribution system.
Grid connectionJoining a plant that generates electric power to a utility system so that electricity can flow in either direction between the utility system and the…
Grid operatorAn entity that oversees the delivery of electricity over the grid to the customer, ensuring reliability and safety.
Grid-Connected SystemIndependent power systems that are connected to an electricity transmission and distribution system (referred to as the electricity grid) such that the…
Grids1) Squared off areas across the terrain used to define forecast areas. Often 5x5 or 2.5x2.5 kilometer in size.
Grizzly (grizzlie)A coarse screen used to remove oversize pieces from earth or blasted rock. A gate or closure on a chute.
Gro-luxäA wide-spectrum fluorescent lamp suitable for artificial light for plant growth.
Gross Calorific ValueThe heat produced by combusting a specific quantity and volume of fuel in an oxygen-bomb colorimeter under specific conditions.
Gross crop valueThis value is the sum of annual receipts from sale of crops produced. Production of crops, such as pasture and hay which normally are consumed on the farm…
Gross GenerationThe total amount of electricity produced by a power plant.
Gross heating value (GHV)The maximum potential energy in the fuel as received, considering moisture content (MC). It reflects the heat used to evaporate moisture.
Gross Vehicle Weight Rating (GVWR)The maximum weight of a vehicle, including curb weight (the weight of the vehicle on its own) and payload (the weight of cargo).
GroundA device used to protect the user of any electrical system or appliance from shock.
Ground Blizzard WarningWhen blizzard conditions are solely caused by blowing and drifting snow.
Ground ClutterA pattern of radar echoes from fixed ground targets (buildings, hills, etc.) near the radar.
Ground failurePermanent ground displacement capable of damaging structures that may occur as a result of differential settlement, liquefaction, lateral spreading, or…
Ground fault matsMats made of insulating materials that do not conduct electricity.
Ground Fog(abbrev. GF) Fog produced over the land by the cooling of the lower atmosphere as it comes in contact with the ground.
Ground Heat FluxThe flux of heat from the ground to the earth's surface; a component of the surface energy budget.
Ground LoopIn geothermal heat pump systems, a series of fluid-filled plastic pipes buried in the shallow ground, or placed in a body of water, near a building.
Ground motionA general term including all aspects of ground motion, namely particle acceleration, velocity, or displacement, from an earthquake or other energy source.
Ground motion (shaking)The movement of the Earth's surface from earthquakes. Ground motion is produced by seismic waves that are generated by a sudden slip on a fault and travel…
Ground motion parametersNumerical values representing vibratory ground motion, such as particle acceleration, velocity, and displacement, frequency content, predominant period…
Ground receive sitesA satellite dish and associated computer which receives signals from the GOES satellite, decodes the information, and transmits it to a another site for…
Ground ReflectionSolar radiation reflected from the ground onto a solar collector.
Ground StrokeThe current that propagates along the ground from the point where a direct stroke of lightning hits the ground.
Ground WaterWater that flows or seeps downward and saturates soil or rock, supplying springs and wells.
Ground Water DivideA line on a water table where on either side of which the water table slopes downward.
Ground Water FlowStreamflow which results from precipitation that infiltrates into the soil and eventually moves through the soil to the stream channel.
Ground Water HydrologyThe branch of hydrology that specializes in ground water; its occurrence and movements; its replenishment and depletion; the properties of rocks that…
Ground Water MiningPumping ground water from a basin where the safe yield is very small, thereby extracting ground water which had accumulated over a long period of time.
Ground water mining (overdraft)Pumping of ground water for irrigation or other uses, at rates faster than the rate at which the ground water is being recharged.
Ground Water OutflowThat part of the discharge from a drainage basin that occurs through the ground water.
Ground water rechargeThe flow to ground water storage from precipitation, inflitration from streams, and other sources of water.
Ground Water RunoffThat part of the runoff which has passed into the ground, has become ground water, and has been discharged into a stream channel as spring, or seepage…
Ground water tableThe upper boundary of ground water where water pressure is equal to atmospheric pressure, i.e.
Grounded iceIce that has run aground or is contact with the ground underneath it.
GroundwaterAll water below the surface of the land. It is water found in the pore spaces of bedrock or soil, and it reaches the land surface through springs or it…
Groundwater basin: (1) A general term used to define a groundwater flow system that has defined boundaries and may include permeable materials that are capable of storing…
Groundwater overdraftThe condition in which water extractions from an aquifer exceed recharge processes in such excess as to cause substantial and sustained decreases in…
Groundwater rechargeInflow of water to a ground-water reservoir from the surface. Infiltration of precipitation and its movement to the water table is one form of natural…
Group VelocityThe speed at which a particular wave front or swell train advances.
GroutA fluid mixture of cement and water or sand, cement, and water used to seal joints and cracks in a rock foundation.
Grout BlanketAn area of the foundation systematically grouted to a uniform shallow depth.
Grout capA concrete pad or wall constructed to facilitate subsequent pressure grouting of the grout curtain beneath the grout cap.
Grout CurtainA barrier produced by injecting grout into a vertical zone, usually narrow (horizontally), and in the foundation to reduce seepage under a dam.
Grout Curtain (Grout Cutoff)A vertical zone, usually thin, in the foundation into which grout is injected to reduce seepage beneath a dam.
GroutingFilling cracks and crevices with a cement mixture.
Growing Degree DayThe number of degrees that the average temperature is above a baseline value. For example, 40 degrees for canning purposes; 45 degree for potatoes; and 50…
Growing SeasonThe period, often the frost-free period, during which the climate is such that crops can be produced.
GrowlerSimilar to a bergy bit, but smaller, extending less than 1 meter above the sea surface and occupying an area of 20 square meters or less.
growth cabinetAn enclosed space in which environmental conditions can be controlled. The degree of control over temperature, light and humidity is a function of the…
growth factor(grohth FAK-ter) A substance made by the body that functions to regulate cell division and cell survival.
Growth FactorsSubstances sometimes given to transplant patients to stimulate the production of blood cells, or to stem cell donors to mobilize stem cells into the…
growth hormoneA protein made by the pituitary gland that helps control body growth and the use of glucose and fat in the body. Also called somatotropin.
growth inhibitorAny substance inhibiting the growth of an organism. The inhibitory effect can range from mild inhibition (growth retardation) to severe inhibition or…
Growth ManagementA term that encompasses a whole range of policies designed to control, guide, or mitigate the effects of growth.
growth phaseEach of the characteristic periods in the growth curve of a bacterial culture, as indicated by the shape of a graph of viable cell number versus time…