Meteorology and atmospheric science terminology · MLC-0110

Meteorology and atmospheric science terms: G (396)

• GGusts- A rapid fluctuation of wind speed with variations of 10 knots or more between peaks and lulls.
• GageIn hydrologic terms, 1) A device for indicating the magnitude or position of a thing in specific units, when...
• Gage datumA horizontal surface used as a zero point for measurement of stage or gage height. This surface usually is...
• Gaging stationIn hydrologic terms, a particular site on a watercourse where systematic observations of stage/ and or flow...
• GainA measure of a radar or radio antenna's ability to direct or concentrate a radio frequency signal in a...
• GaleA strong wind, typically associated with a Beaufort scale force of 8 or 9. A force 8 gale corresponds to wind...
• Gale warningA marine weather warning that sustained winds of 34 to 47 knots (39 to 54 mph, 63 to 87 km/h) are occurring...
• Gale watchA watch for an increased risk of a gale force wind event for sustained surface winds, or frequent gusts, of...
• Galerkin approximationA numerical method used to find approximate solutions to differential equations by projecting the residual...
• Galerkin methodsA class of numerical techniques for solving differential equations by transforming them into a system of...
• GalerneA cold, strong, and squally northwest wind that affects the western and central regions of France...
• GalileiA unit of acceleration, equal to one centimeter per second squared (cm/s²). It is primarily used in...
• GallegoA cold, penetrating wind from the north or northwest that affects Spain and Portugal, named for Galicia, the...
• GalleryIn hydrologic terms, a passageway within the body of a dam or abutment.
• GalliumA soft, silvery-white metal with a low melting point, sometimes used in specialized meteorological...
• GammaA unit of magnetic field intensity equal to 1 x 10.0^(-5) Gauss; also equal to 1 nanotelsa (nT).
• Gamma distributionA continuous probability distribution that is often used to model positive-valued random variables, such as...
• Gamma rayA form of electromagnetic radiation of very high frequency and energy, produced by radioactive decay of...
• Gamma-ray snow gaugeAn instrument used to measure the water equivalent of snowpack by detecting the attenuation of natural gamma...
• Gap windA strong local wind that blows through a gap, pass or gorge in a mountain range, driven mainly by the...
• Gap winds, see Gap wind
• GarbinA name for a southwesterly wind of southern European coasts. In southwestern France it denotes a...
• Garrett-Munk spectrumAn empirical model that describes the statistical distribution of energy among internal waves in the deep...
• GarúaA dense, drizzling fog or mist that forms along the arid coastal regions of Peru, Ecuador, and northern...
• Gas chromatographyAn analytical technique that separates and identifies components within a gaseous or volatile liquid sample...
• Gas constantA physical constant that relates the energy scale to the temperature scale for a given amount of substance...
• Gas filter correlation spectroscopyA remote sensing technique used to measure the concentration of specific atmospheric gases by exploiting...
• Gas lawsA set of empirical laws describing the relationships between the pressure, volume, and temperature of a gas...
• Gas thermometerA device that measures temperature by observing the pressure or volume changes of a fixed amount of gas. It...
• Gas transferThe movement of gases between different environmental compartments, such as from the atmosphere to the ocean...
• Gas-particle distribution factorA ratio giving the share of an airborne species found in the particle phase out of its combined gas and...
• Gas-phase kineticsThe study of the rates and mechanisms of chemical reactions occurring between molecules in the gaseous state...
• GateIn hydrologic terms, a device in which a leaf or member is moved across the waterway from an external...
• Gate-to-gate azimuthal shearA measure of the change in radial velocity between adjacent radar gates along a constant range from the...
• GatingA technique used in radar signal processing to isolate and analyze echoes from specific ranges or velocities...
• Gauge heightThe elevation of the water surface in a stream or river relative to an arbitrary fixed datum, typically...
• Gauge relationA relationship, drawn as a graph or fitted curve, between river stages observed at two gauging stations, one...
• Gauge zeroThe arbitrary reference elevation or datum from which gauge height measurements are taken at a stream gauging...
• Gauging sectionA specific cross-section of a river or stream where hydrometric measurements are regularly taken to monitor...
• Gauging siteA specific location established for the systematic measurement of hydrological or meteorological parameters...
• GaussA unit of magnetic flux density in the CGS (centimeter-gram-second) system of units, named after Carl...
• Gauss curveAnother name for the normal distribution curve, a symmetrical, bell-shaped probability distribution that...
• Gauss eliminationA systematic algorithm for solving systems of linear algebraic equations by transforming the system's...
• Gaussian gridA specific type of latitude-longitude grid used in atmospheric and climate models, where the grid points in...
• Gaussian plume modelA computer model used to calculate air pollution concentrations. The model assumes that a pollutant plume is...
• Gaussian plume models, see Gaussian plume model
• Gaussian processA stochastic process where any finite collection of random variables has a multivariate normal distribution...
• Gaussian puff modelA model used to calculate air pollution concentrations. The model assumes that a continuously emitted plume...
• Gaussian wave packetA localized wave disturbance whose amplitude is described by a Gaussian function, resulting in a...
• GCA minimumsThe lowest weather conditions, specified as a minimum ceiling height and visibility, under which a pilot is...
• GDROn a buoy report, direction, in degrees clockwise from true North, of the GSP, reported at the last hourly...
• GegenscheinA faint patch of light in the night sky centered on the antisolar point, directly opposite the Sun. It is...
• GEMPAKGeneral Environmental Meteorological Package (programming language)
• GENGeneral
• General broadcastA routine radio transmission of weather and sea-state information to ships and other users over a broad area...
• General circulationThe large-scale, planetary-wide patterns of atmospheric and oceanic motion that redistribute heat and...
• General circulation modelA complex numerical model that simulates the Earth's climate system by solving a set of mathematical...
• General circulation models, see General circulation model
• General windLand management agency term for winds produced by synoptic-scale pressure systems on which smaller-scale or...
• Generalized absorption coefficientA measure of how effectively a substance absorbs electromagnetic radiation over a broad range of wavelengths...
• Generalized coordinatesA set of independent parameters used to specify the configuration of a dynamic system, not necessarily...
• Generalized hydrostatic equationA modified form of the hydrostatic equation that accounts for additional forces or coordinate systems beyond...
• Generating areaThe region of the sea surface where a wind field is actively building waves, characterized by the wind speed...
• Generating cellA localized region within a cloud system where new precipitation particles are actively forming and growing...
• GenitusA qualifier in cloud classification showing that a cloud formed from the growth or spreading of part of...
• Genoa cycloneA low-pressure system that forms or intensifies in the lee of the Alps over the Gulf of Genoa and the...
• Gentle breezeA wind with a speed ranging from 8 to 12 miles per hour (13 to 19 kilometers per hour) on the Beaufort scale...
• Geocentric reference systemA coordinate system whose origin is located at the center of the Earth. This system is used for precise...
• Geodesic gridA type of grid used in numerical models, particularly for global atmospheric and oceanic simulations, where...
• GeodesyThe scientific discipline concerned with measuring and representing the Earth's shape, orientation in space...
• Geodetic SatelliteAn artificial satellite specifically designed to measure the Earth's shape, gravity field, and crustal...
• Geographic effect on windsThe influence of Earth's surface features, such as mountains, coastlines, and land-sea boundaries, on the...
• Geographically possible sunshine durationThe longest time the Sun could shine on a given day at a place under a perfectly clear sky, allowing for the...
• GeohydrologyIn hydrologic terms, the branch of hydrology relating to subsurface, or subterranean waters.
• GeoidThe theoretical shape of the Earth's surface that would coincide with mean sea level if the oceans were...
• GEO-KOMPSAT 2AA South Korean geostationary weather satellite launched on 4 December 2018 and operated by the Korea...
• Geologic ageA division of geologic time, representing a relatively short interval within an epoch, characterized by...
• Geologic epochA subdivision of a geologic period, representing a distinct interval of Earth's history characterized by...
• Geologic eraA major division of geologic time, encompassing multiple periods and characterized by profound global changes...
• Geologic periodA primary division of geologic time, longer than an epoch and shorter than an era, characterized by major...
• Geologic timeThe vast span of time from Earth's formation to the present, organized into a hierarchical system of eons...
• Geomagnetic coordinatesA coordinate system used to describe locations on Earth relative to the geomagnetic poles and equator, which...
• Geomagnetic elementsIn solar-terrestrial terms, the components of the geomagnetic field at the surface of the earth. In SESC use...
• Geomagnetic equatorThe great circle on the Earth that lies 90 degrees from the two geomagnetic poles, the equator of the...
• Geomagnetic fieldThe magnetic field observed in and around the earth. The intensity of the magnetic field at the earth's...
• Geomagnetic latitudeThe angular distance of a point on the Earth's surface north or south of the geomagnetic equator, measured...
• Geomagnetic meridianA great circle on the Earth's surface that passes through the geomagnetic north and south poles. These lines...
• Geomagnetic poleEither of the two antipodal points where the axis of the best-fitting dipole centered in the Earth meets the...
• Geomagnetic stormIn solar-terrestraial terms, a worldwide disturbance of the earth's magnetic field, distinct from regular...
• GeomagnetismThe study of the Earth's magnetic field, its origin, variations, and effects. This field is generated by...
• Geometric meanA type of mean or average that indicates the central tendency of a set of numbers by multiplying them...
• Geometric opticsA model of light propagation that treats light as rays traveling in straight lines, neglecting its wave...
• GeomorphologyThe scientific study of the Earth's surface features, their formation, evolution, and the processes that...
• Geophysical dayA day set aside in the international geophysical calendar for coordinated observations by stations around the...
• Geophysical eventsIn solar-terrestrial terms, flares (Importance two or larger) with Centimetric Outbursts (maximum of the flux...
• GeophysicsThe study of the Earth using quantitative physical methods, encompassing phenomena such as seismic waves...
• GeopotentialThe work required to raise a unit mass from sea level to a specific height in the Earth's gravitational...
• Geopotential fieldA scalar field representing the geopotential at every point in the atmosphere. It describes the distribution...
• Geopotential heightThe height of a pressure surface above mean sea level, adjusted to account for variations in gravity with...
• Geopotential meterA unit of geopotential height, defined as the geopotential divided by the standard acceleration of gravity...
• Geopotential surfaceA surface in the atmosphere where the geopotential is constant. These surfaces are analogous to equipotential...
• Geopotential thicknessThe vertical distance, expressed in geopotential meters, between two constant pressure surfaces in the...
• Geopotential topographyThe representation of atmospheric pressure surfaces by their geopotential height above mean sea level. These...
• GEOSATA United States Navy altimeter satellite, launched in 1985, designed to measure sea surface height with high...
• GeosphereThe solid part of the Earth, including the crust, mantle, and core. It encompasses all the rocks, minerals...
• Geostationary Earth Radiation BudgetAn instrument designed to measure the Earth's radiation budget from a geostationary orbit, providing data on...
• Geostationary Lightning MapperA satellite instrument that detects and maps total lightning (in-cloud, cloud-to-cloud, and cloud-to-ground)...
• Geostationary Meteorological SatelliteA type of weather satellite that orbits the Earth at an altitude of approximately 35,786 kilometers (22,236...
• Geostationary operational environmental satelliteA type of weather satellite that orbits the Earth at the same rate as the Earth's rotation, remaining above a...
• Geostationary Operational Meteorological SatelliteThe Russian geostationary meteorological satellite program, which began with GOMS Elektro, launched in 1994...
• Geostationary satelliteAn artificial satellite that orbits the Earth directly above the equator at an altitude where its orbital...
• GeostrophicA condition of atmospheric or oceanic flow in which the Coriolis force exactly balances the horizontal...
• Geostrophic adjustmentThe process by which a fluid system, such as the atmosphere or ocean, responds to an initial imbalance...
• Geostrophic advectionThe horizontal transport of a scalar quantity, such as temperature or moisture, by a geostrophic wind. This...
• Geostrophic approximationA simplification of the equations of motion in which the horizontal pressure gradient force is assumed to be...
• Geostrophic balanceA condition in fluid dynamics where the horizontal pressure gradient force is precisely offset by the...
• Geostrophic coordinatesA transformed set of horizontal coordinates used in semigeostrophic theory, in which each position is shifted...
• Geostrophic currentAn ocean current that results from a balance between the Coriolis force and the horizontal pressure gradient...
• Geostrophic departureThe difference between the actual wind velocity and the geostrophic wind velocity at a given point in the...
• Geostrophic deviationThe vector difference between the actual wind velocity and the geostrophic wind velocity. This deviation...
• Geostrophic dividersA specialized plotting tool used in meteorology to graphically determine the geostrophic wind speed and...
• Geostrophic drag coefficientA dimensionless parameter that relates the surface stress (drag) exerted by the atmosphere to the geostrophic...
• Geostrophic equilibriumA state of motion in which the horizontal Coriolis force exactly cancels the horizontal pressure gradient...
• Geostrophic flowAn idealized horizontal flow in a rotating fluid, such as the atmosphere or ocean, where the Coriolis force...
• Geostrophic fluxThe transport of a quantity, such as heat, momentum, or mass, by a geostrophic flow. This flux is calculated...
• Geostrophic momentum approximationAn approximation of the horizontal momentum equations in which the momentum being accelerated is replaced by...
• Geostrophic vorticityThe component of vorticity that is derived solely from the geostrophic wind field. It represents the rotation...
• Geostrophic windA theoretical wind that results from a perfect equilibrium between the pressure gradient force and the...
• Geostrophic wind levelThe atmospheric altitude above which the wind is considered to be in geostrophic balance, meaning the...
• Geostrophic wind scaleA graphical tool used on weather maps to estimate the magnitude of the geostrophic wind based on the spacing...
• GeosynchronousTerm applied to any equatorial satellite with an orbital velocity equal to the rotational velocity of the...
• Geosynchronous satelliteAn Earth satellite whose orbital period equals the Earth's rotation period of about 23 hours 56 minutes...
• GERBThe Geostationary Earth Radiation Budget experiment, an instrument designed to measure the Earth's radiation...
• Gerdien aspiratorAn instrument designed to measure the electrical conductivity of the atmosphere by collecting charged...
• Gerstner waveAn exact, rotational solution to the Euler equations for a periodic surface gravity wave on an inviscid...
• GestaltThe overall pattern, configuration, or structure of a meteorological field as displayed on a weather map or...
• GeyserA type of hot spring that periodically erupts, forcefully ejecting a column of hot water and steam into the...
• GFGround Fog- Fog produced over the land by the cooling of the lower atmosphere as it comes in contact with the...
• GFS(Global Forecast System) One of the operational forecast models run at NCEP. The GFS is run four times daily...
• GharbiA local wind in North Africa, particularly in Morocco, that blows from the west or southwest. This wind is...
• GhibliA hot, dry, southerly or southeasterly wind that occurs in Libya, originating over the Sahara Desert. This...
• GhostA spurious indication on a radar display that does not correspond to a real target at the position shown...
• Gibbs functionA thermodynamic potential, also known as Gibbs free energy, that measures the maximum reversible work that...
• GiblaA hot, dry, and dusty southerly wind experienced in Tunisia and other parts of North Africa, originating from...
• Gibraltar outflow waterA mass of warm, highly saline water that flows from the Mediterranean Sea into the Atlantic Ocean through the...
• GigahertzA unit of frequency equal to one billion (10^9) cycles per second. In meteorology, it describes the frequency...
• Gill anemometerA type of propeller anemometer designed to measure wind speed and direction, particularly in turbulent or...
• GISGeographic Information System. A computer-based graphics program that allows the superposition of plan-maps...
• G/KGGrams per Kilogram
• GlacialRelating to or characterized by the presence and action of glaciers or ice sheets. It describes periods of...
• Glacial anticycloneA persistent high-pressure system that forms over large continental ice sheets, such as those that covered...
• Glacial driftAll rock and sediment material transported and deposited by a glacier or by meltwater streams originating...
• Glacial epochA major geological period characterized by the presence of extensive ice sheets and glaciers across large...
• Glacial geologyThe branch of geology that studies the processes and landforms associated with glaciers and ice sheets, both...
• Glacial maximumA period within a glacial epoch when global ice volume and the extent of glaciers and ice sheets reached...
• Glacial periodA colder interval within a glacial epoch characterized by the expansion of glaciers and ice sheets across...
• Glacial reboundThe slow, upward movement of the Earth's crust in regions that were once depressed by the immense weight of...
• Glacial troughA U-shaped valley carved by the erosive action of a glacier, typically characterized by steep, straight sides...
• GlaciationThe process of being covered by glaciers or ice sheets, or the geological period during which this occurs. It...
• Glaciation limitThe lowest elevation at which perennial snow and ice can persist on a mountain or landmass, indicating the...
• GlacierA large, persistent body of dense ice that forms from accumulated snow over many years, compacting under its...
• Glacier dammed lakeIn hydrologic terms, the lake formed when a glacier flows across the mouth of an adjoining valley and forms...
• Glacier floodA sudden release of a large volume of water from a glacier or glacier-dammed lake, often triggered by the...
• Glacier flowThe movement of glacial ice under its own weight and the influence of gravity, occurring through internal...
• Glacier frontThe lowest, outermost edge of a glacier, where the ice terminates and often melts or calves into water. This...
• Glacier iceDense, recrystallized ice that forms from compacted snow over many years, characterized by its blue...
• Glacier tongueA narrow, elongated extension of a glacier that projects into a valley or out over a body of water. This...
• Glacier windA shallow, cold wind that flows down the surface of a glacier, driven by the cooling of air in contact with...
• GlacierizationThe process by which an area becomes covered by glaciers or ice sheets. This involves the long-term...
• GlaciologyThe scientific study of glaciers, ice sheets, and all natural phenomena involving ice, including their...
• GlaçonA relatively flat piece of floating sea ice less than 20 m across, which is the French term for what the WMO...
• GlareIntense and uncomfortable brightness caused by direct or reflected sunlight, often reducing visibility and...
• Glare iceA coating of clear, smooth, and transparent ice formed on surfaces, typically from the freezing of rain or...
• GlazeA coating of clear, smooth ice, with some trapped air pockets, formed on exposed objects when a film of...
• Glaze stormA weather event characterized by the accumulation of a layer of ice, known as glaze, on exposed surfaces...
• Glazed frostA deposit of clear, hard ice that forms on surfaces when supercooled water droplets or rain freeze upon...
• GLF(Open Lakes Forecast) - A National Weather Service marine forecast product for the U.S. waters within a Great...
• Glide pathThe vertical descent path that an aircraft follows when approaching a runway, usually set at an angle of...
• GlitterA shimmering or sparkling effect observed on a water surface, caused by the reflection of sunlight or...
• Global area coverageA type of satellite data product that provides a lower-resolution, daily global view of the Earth's surface...
• Global baseline datasetsCollections of long-term, consistent, and high-quality observational data that serve as a reference for...
• Global circuitA conceptual model describing the continuous flow of electrical current through the Earth's atmosphere...
• Global Data Processing SystemAn international network of operational meteorological centers coordinated by the World Meteorological...
• Global Ensemble Forecast SystemA weather forecast model made up of 21 separate forecasts, or ensemble members. The National Centers for...
• Global Forecast System(GFS)- One of the operational forecast models run at NCEP. The GFS is run four times daily, with forecast...
• Global Level of the Sea SurfaceThe full name behind the acronym GLOSS, a program of the Intergovernmental Oceanographic Commission that...
• Global Observing SystemA coordinated worldwide system of meteorological and environmental observing stations and platforms, managed...
• Global Positioning SystemA satellite-based navigation system that provides precise location and time information anywhere on Earth...
• Global radiationThe total solar radiation received on a horizontal surface, comprising both direct solar radiation and...
• Global Telecommunications SystemA coordinated global network of telecommunication facilities and arrangements for the rapid collection...
• Global temperature changeThe net result of four primary factors including the greenhouse effect, changes in incoming solar radiation...
• Global WarmingAn overall increase in world temperatures which may be caused by additional heat being trapped by greenhouse...
• GloryAn optical phenomenon appearing as one or more concentric rings of colored light, centered on the observer's...
• Glow dischargeA luminous electrical discharge that occurs in a gas at low pressure, characterized by a faint glow. This...
• GLS(Great Lakes Storm Summary) A National Weather Service forecast product providing updated information...
• GMDSS(Global Maritime Distress and Safety System)- The Global Maritime Distress and Safety System (GMDSS) is...
• GMNOn a buoy report, the minute of the hour that the GSP occurred, reported at the last hourly 10-minute segment.
• GMTGreenwich Mean Time (now known as Universal Coordinated Time)
• GNDGround
• GNRLGeneral
• GoesA series of geostationary operational environmental satellites operated by the United States, providing...
• GOES High-Resolution Interferometer SounderAn advanced instrument designed for future Geostationary Operational Environmental Satellites to provide...
• GOES VariableA digital broadcast format, abbreviated GVAR, in which the Imager and Sounder instruments of GOES-8 through...
• GOES-RThe designation for the next generation of Geostationary Operational Environmental Satellites, which began...
• Goldbeater's skin hygrometerA type of hygrometer that measures atmospheric humidity by observing the expansion and contraction of a thin...
• GolfadaA heavy gale or storm wind of the Mediterranean Sea, the name coming from the sailors' speech of the Spanish...
• GoMoosGulf Of Maine Ocean Observing System
• GoniometerAn instrument used to measure angles, particularly in the context of atmospheric science for determining the...
• Goodness of fitA statistical measure that describes how well a mathematical model or distribution fits a set of observed...
• Gorge windA localized wind that is channeled and intensified as it flows through a narrow valley or gorge. The...
• Gosling blastA sudden squall of rain or sleet, a traditional English country name for a short sharp storm of this kind...
• Gowk stormA period of stormy, unseasonably cold weather that occurs in late spring, particularly in parts of the United...
• GPSAn acronym for Global Positioning System. A network of satellites which provide extremely accurate position...
• Grab samplingA method of collecting a single, discrete sample of air or water at a specific time and location, intended to...
• GRADGradient- A rate of change with respect to distance of a variable quantity, as temperature or pressure, in...
• Gradex methodA hydrological method, proposed in France by Guillot and Duband in the late 1960s, for estimating the...
• GradientThe rate of change of a physical quantity with respect to distance in a particular direction. In meteorology...
• Gradient currentAn ocean current driven by horizontal differences in water density, which create pressure gradients within...
• Gradient flowAtmospheric motion where the air parcel is in equilibrium between the pressure gradient force, the Coriolis...
• Gradient high windsThese high winds usually cover a large area and are due to synoptic-scale, extra-tropical low pressure...
• Gradient Richardson numberA dimensionless parameter used in fluid dynamics and meteorology to characterize the stability of a...
• Gradient transport theoryA conceptual framework that describes the transport of atmospheric properties, such as heat, momentum, and...
• Gradient windThe theoretical horizontal wind that results from a balance between the pressure gradient force, the Coriolis...
• Gradient-based similarity theoryA similarity approach for the stably stratified atmospheric boundary layer in which the scaling variables are...
• GradingThe process by which a land surface is worn down toward a uniform, nearly level slope, as when erosion and...
• Gradual commencementIn solar-terrestrial terms, the commencement of a geomagnetic storm that has no well-defined onset
• GraduationThe process of smoothing or adjusting a series of observed data points to remove irregularities and reveal...
• Grains of iceVery small white opaque grains of ice, usually under 1 mm across and fairly flat or elongated, that fall from...
• GramA unit of mass in the metric system, equal to one thousandth of a kilogram. In meteorology, it is frequently...
• Gram calorieA unit of energy representing the amount of heat required to raise the temperature of one gram of water by...
• Gram-moleThe amount of a substance that has a mass in grams numerically equal to its molecular weight. This unit is...
• Granular snowA type of coarse, grainy snow composed of large, distinct ice crystals that are loosely bonded together. It...
• GranulationIn solar-terrestrial terms, the cellular structure of the photosphere visible at high spatial resolution.
• GranulesSmall, transient convective cells visible on the Sun's photosphere, appearing as bright, polygonal areas...
• Grashoff numberA dimensionless number in fluid dynamics that characterizes the ratio of buoyancy forces to viscous forces...
• GrassVegetation consisting of herbaceous plants with narrow leaves growing from the base, forming a ground cover...
• Grass minimumThe lowest temperature recorded overnight by a thermometer placed horizontally just above the tips of short...
• Grass temperatureThe temperature measured by a thermometer with its bulb exposed to the open air and positioned just above the...
• GraupelPrecipitation consisting of ice particles that form when supercooled water droplets accrete onto an ice...
• Gravimetric hygrometryA method for measuring atmospheric humidity by determining the mass of water vapor absorbed from a known...
• GravitationThe universal force of attraction between all matter, proportional to the product of their masses and...
• Gravitational headThe potential energy per unit weight of a fluid due to its elevation above a reference datum. In atmospheric...
• Gravitational potentialThe potential energy per unit mass at a given point in a gravitational field. It represents the work done by...
• Gravitational potential energyThe energy an air parcel possesses due to its vertical position within Earth's gravitational field. It is...
• Gravitational tideThe periodic deformation of the Earth's atmosphere, oceans, and solid body caused by the gravitational pull...
• Gravitational waterWater that moves downward through the soil profile under the influence of gravity, eventually draining away...
• GravityThe force that attracts a body toward the center of the Earth, or toward any other physical body having mass...
• Gravity currentA horizontal flow of a fluid driven by density differences, where a denser fluid displaces a lighter fluid...
• Gravity damIn hydrologic terms, a concrete structure proportioned so that its own weight provides the major resistance...
• Gravity flowThe movement of a fluid, such as air or water, driven primarily by density differences under the influence of...
• Gravity Recovery and Climate ExperimentNASA satellites that detect small changes in the Earth’s gravitational field caused by the redistribution of...
• Gravity waveA wave in a fluid medium where the restoring force is gravity or buoyancy. In the atmosphere, these waves are...
• Gravity wave dragA force exerted on the atmosphere by the breaking of gravity waves, which are oscillations in a fluid medium...
• Gravity wave drag parameterizationA method used in atmospheric models to represent the momentum transfer from the atmosphere to the Earth's...
• Gravity windA local wind system driven by the gravitational force acting on a mass of air that is denser than its...
• Gray absorberA hypothetical substance or atmospheric layer that absorbs radiation with an absorptivity that is constant...
• Gray iceNewly formed sea ice that is between 10 and 15 centimeters thick, characterized by its grayish appearance...
• GraybodyA hypothetical object that emits and absorbs radiation at a constant emissivity, which is less than one...
• GrayscaleA range of shades from pure black to pure white, used to represent data where color information is not...
• GRDLGradual
• Grease iceA very early stage of sea ice formation, consisting of a soupy layer of ice crystals on the ocean surface...
• Great Basin highA semi-permanent high-pressure system that develops over the Great Basin region of the western United States...
• Great circleA circle on the surface of a sphere whose plane passes through the center of the sphere. The equator and all...
• Great circle trackA great-circle track is the shortest distance between two points on a sphere, and when viewed on a...
• Great Lakes faxbackDissemination systems housed at Weather Forecast Office (WFO) Cleveland by which Great Lakes customers...
• Great Lakes Freeze-Up/Break-Up Outlook(FBO) - A National Weather Service product to keep mariners informed of the projected freeze-up date or...
• Great Lakes Marine ForecastA National Weather Service coded summary appended to each of the Great Lakes Open Lakes forecasts.
• Great Lakes storm summary(GLS) - A National Weather Service forecast product providing updated information whenever a storm warning is...
• Great Lakes weather broadcast(LAWEB) - A National Weather Service product containing an observation summary prepared to provide Great...
• Great-circle courseThe shortest path between two points on the surface of a sphere, which follows an arc of a great circle. In...
• GrecoA northeasterly wind occurring in the central Mediterranean Sea, particularly the Ionian Sea. The name...
• Green flashA rare optical phenomenon occurring at sunrise or sunset, where a green spot or ray of light is visible above...
• Green icebergAn iceberg that appears green due to the presence of marine algae or dissolved organic matter incorporated...
• Green lineThe green line is one of the strongest (and first-recognized) visible coronal lines. It identifies moderate...
• Green rimA thin green fringe along the upper edge of the Sun's disk when the Sun is near the horizon, caused by...
• Green snowSnow that exhibits a green coloration, typically caused by the presence of microscopic algae or other...
• Green thunderstormA thunderstorm cloud that exhibits a greenish hue, often associated with severe weather conditions. The green...
• Greenhouse effectThe process by which certain gases in a planet's atmosphere trap thermal radiation, warming the surface to a...
• Greenhouse gas stabilizationThe process of achieving and maintaining a specific concentration of greenhouse gases in the atmosphere to...
• Greenhouse gasesAtmospheric gases that absorb and emit infrared radiation, thereby trapping heat within the Earth's...
• Greenland anticycloneA persistent high-pressure system located over the Greenland ice sheet, characterized by descending air and...
• Greenland ice sheetA vast body of glacial ice covering approximately 80% of the surface of Greenland, making it the...
• Greenland Sea Deep WaterA cold, dense water mass formed in the Greenland Sea through intense cooling and convection, which then sinks...
• Green's functionA mathematical tool used to solve inhomogeneous linear differential equations, particularly those arising in...
• Green's theoremA mathematical relationship that connects a line integral along a simple, closed, piecewise-smooth curve in a...
• GregaleA strong, cold, and dry northeasterly wind that affects the central Mediterranean Sea, particularly Malta and...
• G-regionA historical designation for a hypothesized layer of ionization in the ionosphere situated above the F...
• Gregori windA local easterly wind of the Tyrol region of the Alps, noted for blowing in March and April. The name is a...
• Grenade soundingA method of atmospheric sounding that involves launching small explosive devices, or grenades, into the upper...
• GRIBA World Meteorological Organization (WMO) standard format for the efficient storage and transmission of...
• GridA network of intersecting lines, typically orthogonal, used to discretize a continuous spatial domain for...
• Grid headingA direction measured relative to a grid north, which is a fixed direction on a grid system, rather than true...
• Grid lengthThe spatial resolution or distance between adjacent grid points in a numerical model of the atmosphere or...
• Grid meridiansLines of constant grid longitude in a grid coordinate system, which are parallel to the central grid...
• Grid navigationA navigational technique used primarily in polar regions for determining direction and position relative to a...
• Grid nephoscopeAn instrument used to determine the direction and speed of cloud movement by observing the apparent motion of...
• Grid telescopingA technique used in numerical models where the spatial resolution of the computational grid is varied, with...
• Grid turbulenceTurbulence generated by passing a fluid flow through a grid or screen, often used in laboratory experiments...
• GriddingThe process of interpolating irregularly spaced data points onto a regular grid or mesh. This technique is...
• Grids, see Grid
• Gross interception lossThe total amount of precipitation that is caught and held by vegetation surfaces, such as leaves and...
• Gross primary productionThe total amount of organic matter, or biomass, produced by photosynthetic organisms within an ecosystem over...
• Gross-austauschThe large-scale turbulent exchange of mass and atmospheric properties such as heat, momentum, and water...
• GrosswetterlageA large-scale, quasi-stationary atmospheric circulation pattern that dominates the weather over a broad...
• Ground blizzard warningWhen blizzard conditions are solely caused by blowing and drifting snow.
• Ground checkA verification process for meteorological instruments or data, performed by comparing readings against a...
• Ground clutterUnwanted echoes on a weather radar display caused by the radar beam striking fixed objects on the Earth's...
• Ground flashA lightning discharge that occurs between a thundercloud and the Earth's surface. This type of lightning is...
• Ground fluxThe rate at which heat is conducted into or out of the ground through its surface, written G in the surface...
• Ground fogA fog layer near the surface that hides less than six tenths of the sky and does not reach the base of any...
• Ground frostThe formation of ice crystals on surfaces exposed to the air near the ground, such as grass, car windshields...
• Ground heat fluxThe flux of heat from the ground to the earth's surface; a component of the surface energy budget.
• Ground iceA body of ice formed in or on the ground in perennially frozen regions (permafrost). It includes several...
• Ground illuminationThe amount of light reaching the Earth's surface from natural or artificial sources, influencing visibility...
• Ground inversionAn atmospheric condition where temperature increases with height immediately above the Earth's surface...
• Ground layerThe lowest portion of the atmospheric boundary layer, directly influenced by the Earth's surface. This layer...
• Ground receive sitesIn hydrologic terms, a satellite dish and associated computer which receives signals from the GOES satellite...
• Ground speedThe horizontal velocity of an aircraft or other moving object relative to the Earth's surface. It is the...
• Ground stateThe lowest energy level that an atom, molecule, or other quantum system can occupy. In atmospheric science...
• Ground streamerA luminous discharge that propagates upward from the Earth's surface towards a downward-moving leader during...
• Ground strokeThe current that propagates along the ground from the point where a direct stroke of lightning hits the...
• Ground swellOcean waves that have traveled a considerable distance from their generating storm system, resulting in long...
• Ground targetAny object or area on the Earth's surface that is being observed or measured by remote sensing instruments...
• Ground trackThe path on the Earth's surface directly beneath an aircraft or satellite as it moves through the atmosphere...
• Ground truthInformation collected directly from the Earth's surface to verify and calibrate data obtained through remote...
• Ground visibilityThe horizontal visibility near the Earth's surface as determined by an accredited observer or an automated...
• Ground waterIn hydrologic terms, water within the earth that supplies wells and springs; water in the zone of saturation...
• Ground water divideIn hydrologic terms, A line on a water table where on either side of which the water table slopes downward...
• Ground water flowIn hydrologic terms, streamflow which results from precipitation that infiltrates into the soil and...
• Ground water hydrologyThe branch of hydrology that specializes in ground water; its occurrence and movements; its replenishment and...
• Ground water outflowIn hydrologic terms, the part of the discharge from a drainage basin that occurs through the ground water...
• Ground water overdraftPumpage of ground water in excess of safe yield.
• Ground water runoffThat part of the runoff which has passed into the ground, has become ground water, and has been discharged...
• Ground waveAn electromagnetic wave that travels along the surface of the Earth, following its curvature. This type of...
• Ground-check chamberA sealed enclosure used for testing and calibrating radiosondes and other meteorological instruments at...
• Ground-controlled approachA type of instrument approach procedure where an air traffic controller on the ground provides verbal...
• Grounded iceIn hydrologic terms, ice that has run aground or is contact with the ground underneath it
• Groundhog DayA traditional observance held annually on February 2nd in parts of North America, where a groundhog's...
• Grounding lineThe boundary where a glacier or ice sheet stops resting on bedrock and begins to float on water, so the ice...
• Ground-to-cloud dischargeA rare type of lightning discharge where the electrical breakdown initiates from the ground and propagates...
• GroundwaterWater held underground within the soil, rock fractures, and pore spaces of geological formations. It fills...
• Groundwater basinA hydrogeologic unit defined by the extent of a groundwater system, encompassing the subsurface area where...
• Groundwater damA subsurface barrier constructed across an aquifer to impede the natural flow of groundwater, thereby raising...
• Groundwater datingA technique used to determine the residence time or age of groundwater, indicating how long it has been...
• Groundwater depletion curveA streamflow recession curve plotted for a period without precipitation, adjusted so that its slope shows how...
• Groundwater divideA boundary in the subsurface that separates groundwater flow in different directions, analogous to a surface...
• Groundwater flowThe movement of water beneath the Earth's surface through saturated zones within soil and rock. This flow is...
• Groundwater hydrologyThe scientific study of the occurrence, movement, and distribution of water beneath the Earth's surface. This...
• Groundwater levelThe elevation of the water table, which is the upper surface of the zone of saturation where all pore spaces...
• Groundwater miningThe extraction of groundwater from an aquifer at a rate that exceeds its natural recharge rate. This practice...
• Groundwater moundA localized rise in the water table, typically forming beneath an area of concentrated recharge, such as an...
• Groundwater runoffThe portion of precipitation that infiltrates the ground and moves through the subsurface to eventually...
• Groundwater stationA facility equipped with instruments for monitoring one or more characteristics of groundwater at a specific...
• Groundwater storageThe total volume of water held in aquifers and other underground formations within a defined area. This...
• Group velocityThe velocity at which the overall shape or envelope of a wave packet or wave train propagates through a...
• Grout curtainA barrier produced by injecting grout into a vertical zone, usually narrow (horizontally), and in the...
• Growing degree-dayA measure of heat accumulation used to predict plant and insect development rates, calculated by summing the...
• Growing degree-hourA unit of heat accumulation similar to a growing degree-day, but calculated on an hourly basis. It provides a...
• Growing seasonThe period of the year when local weather conditions, particularly temperature and precipitation, are...
• GrowlerA small piece of floating glacier ice, smaller than a bergy bit, that rises less than 1 m above the sea...
• GRTgreat
• GRTSTGreatest
• G-scaleA scale used to classify the intensity of geomagnetic storms, which are disturbances in Earth's magnetosphere...
• GSPOn a buoy report, maximum 5-second peak gust during the measurement hour, reported at the last hourly...
• GSTOn a buoy report, peak 5 or 8 second gust speed (m/s) measured during the eight-minute or two-minute period...
• GSTYGusty
• GTRGreater
• GubaA rain squall at sea in the waters of New Guinea, a sudden, violent burst of wind and rain over coastal water...
• Guiana CurrentA warm ocean current flowing westward along the northeastern coast of South America, from the mouth of the...
• Guinea CurrentA warm, relatively fresh surface current flowing eastward along the Guinea coast of West Africa into the Gulf...
• Gulf of PapagayoA region off the Pacific coast of Nicaragua and Costa Rica where strong, dry gap winds emerge from the...
• Gulf of TehuantepecA large embayment on the Pacific coast of southern Mexico, known for its strong, gusty winds. These winds...
• Gulf StreamA powerful, warm, and swift Atlantic ocean current that develops in the Gulf of Mexico and follows the...
• Gulf Stream ringsLarge, rotating eddies that pinch off from the main body of the Gulf Stream. Warm core rings form on the...
• Gulf Stream SystemA powerful, warm, and swift ocean current that originates in the Gulf of Mexico and flows northeastward along...
• Gully-squallA sudden, strong downdraft of wind that is channeled through a narrow valley, ravine, or gully, causing a...
• GUNAAverage of GHMI, EGRI, NGPI, and GFSI GHMI: Previous cycle GFDL, adjusted using a variable intensity offset...
• GungeSlang for anything in the atmosphere that restricts visibility for storm spotting, such as fog, haze...
• GustA rapid and brief increase in wind speed above the average wind speed being measured at a given moment. A...
• Gust amplitudeThe maximum change in wind speed during a wind gust, measured as the difference between the peak gust speed...
• Gust decay timeThe interval required for a wind gust's speed to decrease from its peak value back to the mean wind speed or...
• Gust durationThe total time span during which wind speed exceeds a predefined threshold above the mean wind speed. This...
• Gust formation timeThe period over which wind speed rapidly increases from a lower, ambient level to its peak value during a...
• Gust frequencyThe rate at which wind gusts occur within a given time frame, expressed as the number of gust events per unit...
• Gust frontThe leading edge of a mass of cold, dense air that spreads out horizontally from a thunderstorm or downburst...
• Gust loadThe transient aerodynamic force exerted on an object, such as an aircraft wing or a building, due to a sudden...
• Gust peak speedThe highest wind speed reached within a gust, normally taken as the maximum three-second average speed in the...
• Gust probeA specialized instrument designed to measure rapid fluctuations in wind speed and direction, particularly...
• Gust vectorA representation of the instantaneous wind velocity during a gust, indicating both its speed and direction...
• Gust-gradient distanceThe horizontal distance over which a gust's speed changes from its mean value to its peak value. This metric...
• GustinessThe characteristic of wind exhibiting frequent and rapid fluctuations in speed and direction, rather than...
• Gustiness componentsThe individual elements that describe the turbulent, fluctuating nature of wind, typically resolved into...
• Gustiness factorA dimensionless measure of gust intensity: the difference between the wind speed in gusts and the speed in...
• GustnadoA short-lived, shallow vortex that forms along a thunderstorm's gust front, appearing as a rotating column of...
• GustsondeA parachute-borne probe released from high altitude to sense the vertical motions of turbulent air as it...
• Guti weatherA spell of dense, low stratocumulus overcast, often with drizzle, that affects Zimbabwe (formerly Rhodesia)...
• GuttationThe process by which plants exude droplets of xylem sap from the tips or edges of their leaves, typically...
• Guyana CurrentA warm ocean current that flows westward along the northern coast of South America, originating from the...
• GyresLarge systems of rotating ocean currents, driven by global wind patterns, the Coriolis effect, and...
• Gyro-frequencyThe angular frequency at which a charged particle, such as an electron or ion, orbits a magnetic field line...

396 of 10,756 terms in Meteorology and atmospheric science terminology (MLC-0110). Request the full dataset.