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…
Growth phase (curve)The characteristic periods in the growth of a bacterial culture, as indicated by the shape of a graph of viable cell number versus time.
Growth rateA growth rate measures the percentage increase in the value of a variety of markets, companies, or operations.
growth regulatorA synthetic or natural compound that at low concentrations elicits and controls growth responses in a manner similar to hormones.
growth retardantA chemical that selectively interferes with normal hormonal promotion of growth and other physiological processes, but without appreciable toxic effects.
growth ringRings visible in a cross-section of a woody stem, such as a tree trunk. Each ring represents the xylem formed in one year as a result of fluctuating…
growth substanceAny organic substance, other than a nutrient, that is synthesized by plants and regulates growth and development.
guanylic acidSynonym for guanosine monophosphate (abbreviation: GMP), a (ribo)nucleotide containing the.
guard cellSpecialized epidermal cells found in pairs around a stoma. Their function is to control the opening and closing of the stoma through changes in turgor.
Guard gate (emergency)The first gate in a series of flow controls, remaining open while downstream gates or valves are operating.
guide RNAAn RNA molecule that contain sequences that function as a template during RNA editing. See: guide sequence.
guide sequenceAn RNA molecule (or a part of it) which hybridizes with eukaryotic mRNA and aids in the splicing of intron sequences.
Gulf StreamWarm water current extending from the Gulf of Mexico and Florida up the U.S. east coast then east northeast to Iceland and Norway.
GungeSlang for anything in the atmosphere that restricts visibility for storm spotting, such as fog, haze, precipitation (steady rain or drizzle), widespread…
GURTAbbreviation for genetic use restriction technology.
gus geneAn E. coli gene that encodes for production of beta-glucuronidase (GUS). Because this activity is absent in plants, the gene is commonly utilized as a…
Gust(Abbrev. G) - A rapid fluctuation of wind speed with variations of 10 knots or more between peaks and lulls.
Gust FrontThe leading edge of gusty surface winds from thunderstorm downdrafts; sometimes associated with a shelf cloud or roll cloud.
Gustnado(or Gustinado) - [Slang], gust front tornado. A small tornado, usually weak and short-lived, that occurs along the gust front of a thunderstorm.
Guy WireCable use to secure a wind turbine tower to the ground in a safe, stable manner.
GyandromorphOrganisms that have both male and female cells and therefore express both male and female characteristics.
gymnospermA class of plant (e.g. conifers) whose ovules and the seeds into which they develop are borne unprotected, rather than enclosed in ovaries, as are those…
gynandromorphAn individual in which one part of the body is female and another part is male; a sex mosaic.
gynogenesisFemale parthenogenesis : after fertilization of the ovum, the male nucleus is eliminated and the haploid (gynogenetic) individual possesses the maternal…
GypsumA soft mineral composed of hydrated calcium sulfate (CaSO4?2H20); occurs as an evaporite residue from ancient lakes in arid basins (e.g.
Gypsum badlandsBadlands dominated by soils derived from the mineral gypsum (hydrated calcium sulfate).
GyresOceanic current systems of planetary scale driven by the global wind system.
HPrefix used to designate the human form of an enzyme. For example, hGH is human growth hormone.
H-AlphaIn solar-terrestrial terms, this absorption line of neutral hydrogen falls in the red part of the visible spectrum and is convenient for solar…
H-component of the Geomagnetic Field(Geomagnetic Elements) In solar-terrestrial terms, the components of the geomagnetic field at the surface of the earth.
H0On a buoy report, Significant Wave Height is the average height (meters) of the highest one-third of the waves during a 20 minute sampling period.
H5500 millibar level height (in a standard atmosphere this is near 5,500 meters (18,000 ft)
H7height of the 700 millibar level. In a standard atmosphere this is near 3,000 meters (10,000 ft)
H<sub>0</sub>, Hubble ConstantA measure of the expansion rate and age of the universe. It appears to be between 60 and 80 kilometers per second per megaparsec.
HabitatThe natural environment where people, animals and plants live. In an aquatic environment, it includes the water, topography, structure and cover present…
Habitat alterationA change in the particular environment or place where an organism or species lives.
Habitat Areas of Particular Concern (HAPC)(HAPC)A habitat area designated by a Fishery Management Council under the Magnuson-Stevens Fishery Conservation and Management Act of 1976 to help focus…
Habitat degradationDecline in habitat quality that accompanies non-natural forms of disturbance.
Habitat FragmentationDivision of large tracts of natural habitat into smaller, disjunct parcels.
Habitat typeAn aggregation of all land areas potentially capable of producing similar plant communities at climax.
habituationThe phenomenon whereby, after a number of sub-cultures, cells can grow without the addition to the tissue culture medium of previously obligatory factors.
haemoglobinProtein containing iron, located in erythrocytes of vertebrates; important for the transportation of oxygen to the cells of the body.
haemolymphThe mixture of blood and other fluids in the body cavity of an invertebrate.
haemophiliaA sex-linked hereditary bleeding disorder in which it takes a long time for the blood to clot and abnormal bleeding occurs.
Hague LineThe North Atlantic boundary between the U.S. and Canada fishing waters as determined by the World Court in The Hague, Netherlands.
HailShowery precipitation in the form of irregular pellets or balls of ice more than 5 mm in diameter, falling from a cumulonimbus cloud.
Hail ContaminationA limitation in NEXRAD rainfall estimates whereby abnormally high reflectivities associated with hail are converted to rainfall rates and rainfall…
Hail IndexAn indication of whether the thunderstorm structure of each storm identified is conducive to the production of hail.
Hail SizeTypically refers to the diameter of the hailstones. Warnings and reports may report hail size through comparisons with real-world objects that correspond…
Hail SpikeAn area of reflectivity extending away from the radar immediately behind a thunderstorm with extremely large hail.
hailstonesTransparent or partially opaque particles of ice that range in size from that of a pea to that of golf balls.
Haines IndexThis is also called the Lower Atmosphere Stability Index. It is computed from the morning (12Z) soundings from RAOB stations across North America.
hairpin loopA region in one strand of a polynucleotide which, due to an inverted repeat in the sequence, may under appropriate conditions fold back on itself and form…