Meteorology and atmospheric science terminology · MLC-0110

Meteorology and atmospheric science terms: B (491)

BAbbreviation used on long-term climate outlooks issued by CPC to indicate areas that are likely to be below...
Babinet pointA neutral point of skylight polarization located in the sky roughly 15 to 20 degrees above the sun, where the...
Babinet's principleA principle in optics stating that the diffraction pattern produced by an opaque body is identical to that...
Back door cold frontA cold front moving south or southwest along the Atlantic seaboard and Great Lakes; these are especially...
Back-building ThunderstormA thunderstorm in which new development takes place on the upwind side (usually the west or southwest side)...
Backdoor cold frontA type of cold front that approaches from the northeast or east, rather than the more typical northwest or...
BackfireA fire started to stop an advancing fire by creating a burned area in its path.
BackflowIn hydrologic terms, the backing up of water through a conduit or channel in the direction opposite to normal...
Background fieldAn initial estimate of the atmospheric state used in numerical weather prediction models before observations...
Background levelThe concentration of a substance in the atmosphere or environment that is naturally present or results from...
Background pollutionThe general level of atmospheric contaminants present in a region, originating from natural processes or...
BackingA counterclockwise change in wind direction over time at a specific location, or a counterclockwise turning...
Backing windA wind that changes its direction in a counter-clockwise manner over time at a fixed point, or with...
Backing winds, see Backing wind
BacklashThe mechanical clearance or play between interlocking parts of a mechanism, such as the gears in an...
BacklobeA minor lobe in the radiation pattern of an antenna, directed opposite to the main lobe. While the main lobe...
BackpropagationAn algorithm used to train artificial neural networks by iteratively adjusting the network's internal weights...
BackscatterThe redirection of radiation, such as light or sound waves, back towards its source due to interaction with...
Backscattering cross sectionA measure of the effective area of a target that intercepts and scatters electromagnetic radiation directly...
Back-sheared anvilAn anvil cloud that spreads upwind of the main updraft of a thunderstorm, against the direction of the...
BacksightIn hydrologic terms, a rod reading taken on a point of known elevation, a benchmark or a turning point...
BacktrackingThe process of tracing the trajectory of an air parcel or pollutant plume backward in time to determine its...
Backward chainingA reasoning method used in artificial intelligence and expert systems that starts from a potential conclusion...
Backward differenceA numerical approximation of a derivative where the value of a function at a point is subtracted from its...
Backward scattering coefficientA measure of the amount of light scattered by a medium in the direction opposite to the incident radiation...
BackwashThe seaward flow of water down a beach face following the breaking of a wave. This return flow is driven by...
BackwaterThe body of water in a river or stream where the water level is raised above its normal level due to a...
Backwater curveThe longitudinal profile of the water surface in a channel where flow is non-uniform due to the influence of...
Backwater effectIn hydrologic terms, the effect which a dam or other obstruction has in raising the surface of the water...
Backwater floodingHydrologic terms, upstream flooding caused by downstream conditions such as channel restriction and/or high...
Baffin CurrentA cold, southward-flowing ocean current that originates in Baffin Bay and flows along the coast of Baffin...
BaffleA plate, screen, or partition used within a meteorological instrument to obstruct, guide, or regulate the...
BagyoThe regional name for a tropical cyclone that forms or enters the Philippine Area of Responsibility (PAR) in...
BaiA yellow mist or dust haze that is common over China and Japan in spring and autumn. Strong winds raise loose...
Bai-uA distinct rainy season that occurs in East Asia, particularly in Japan, Korea, and parts of China, during...
BalanceA state of equilibrium within the atmosphere or a specific atmospheric system, where opposing forces or...
Balance equationA diagnostic equation in meteorology that relates the geopotential field to the wind field, specifically the...
Balance meterAn instrument designed to measure the net difference between incoming and outgoing energy fluxes at a...
Balance yearThe 12-month period over which the mass balance of a glacier or ice sheet is calculated, representing a full...
Bali windA strong easterly wind at the eastern end of the island of Java, in Indonesia. The name comes from...
Ball lightningA rare and unexplained atmospheric phenomenon described as a luminous, spherical object that appears during...
Ballistic densityA single constant air density, used in ballistic meteorology, that stands in for the real density profile...
BallonetAn internal, air-filled compartment within the envelope of a non-rigid airship or balloon. It is used to...
BalloonAn unpowered, lighter-than-air aircraft used in meteorology to carry instruments aloft for atmospheric...
Balloon ceilingThe ceiling classification used in United States weather observing practice when cloud height is obtained by...
Balloon soundingA meteorological observation technique involving the release of a weather balloon carrying a radiosonde...
BAMBinary Angular Measure
BandA range of wavelengths or frequencies within the electromagnetic spectrum, often used to describe specific...
Band absorptionThe selective absorption of electromagnetic radiation by atmospheric gases within specific wavelength or...
Band modelA simplified mathematical representation used to calculate the absorption and emission of radiation by...
Banded structureA meteorological phenomenon characterized by the appearance of elongated, parallel, or nearly parallel cloud...
Bandpass filterAn electronic or computational filter that allows signals within a specific range of frequencies or...
BandwidthThe range of frequencies or wavelengths in the electromagnetic spectrum that a remote sensing instrument...
BankA raised area of land along the side of a river, lake, or ocean, or a submerged elevation of the seafloor. In...
Bank storageThe water absorbed into the banks of a river or stream channel during periods of high flow, which is then...
BankfullThe water level, or stage, at which a stream, river or lake is at the top of its banks and any further rise...
Bankfull stageThe elevation of the water surface in a river or stream channel when the flow completely fills the channel...
Banner cloudA stationary cloud formation that appears to stream downwind from a mountain peak, resembling a flag or...
BAPSUBay Area Public Service Unit. Public Service section of the San Francisco Bay Area Weather Service Forecast...
BarA unit of pressure, commonly used in meteorology, defined as 100,000 Pascals (Pa) or 100 kilopascals (kPa)...
BaratA heavy northwest squall that strikes Manado Bay on the north coast of the island of Celebes, now Sulawesi...
BarbA short straight line drawn obliquely from the end of a wind-direction shaft on a synoptic chart, toward...
BarberA form of severe coastal weather where supercooled fog or sea spray freezes on contact with ships and other...
Barber pole[Slang], a thunderstorm updraft with a visual appearance including cloud striations that are curved in a...
BarchanA crescent-shaped sand dune with its convex side facing upwind and two 'horns' pointing downwind. These dunes...
Bare iceIce that is exposed directly to the atmosphere, without any insulating layer of snow or other material...
Bare soilLand surface that is devoid of vegetation cover, directly exposed to the atmosphere. The absence of...
Baric topographyThe representation of atmospheric pressure fields on constant pressure surfaces, typically depicted by...
BarinésA strong wind from the west or northwest that blows across the plains of Venezuela and announces the start of...
BaroclinicDescribing an atmospheric state where surfaces of constant pressure intersect surfaces of constant density or...
Baroclinic atmosphereAn atmospheric state where surfaces of constant pressure intersect surfaces of constant density or...
Baroclinic disturbanceA wave-like perturbation in the atmosphere that grows due to baroclinic instability, converting potential...
Baroclinic forecastA numerical weather prediction produced by a model that accounts for baroclinicity, the state where surfaces...
Baroclinic instabilityA dynamic process in a baroclinic atmosphere where small perturbations grow into large-scale weather systems...
Baroclinic leafA cloud feature observed in satellite imagery, characterized by a leaf-shaped pattern of mid- and high-level...
Baroclinic leaf shieldA cloud pattern on satellite images - frequently noted in advance of formation of a low pressure center.
Baroclinic modelA type of numerical weather prediction model that explicitly incorporates the effects of horizontal...
Baroclinic waveA type of atmospheric wave that develops in a baroclinic environment, characterized by a phase difference...
Baroclinic zoneA region in which a temperature gradient exists on a constant pressure surface. Baroclinic zones are favored...
BaroclinityThe atmospheric condition where surfaces of constant pressure (isobaric surfaces) intersect surfaces of...
BarogramA continuous graphical record of atmospheric pressure over time, typically produced by a barograph. The trace...
BarographAn instrument that continuously records atmospheric pressure over time, typically using a pen arm connected...
BarometerAn instrument used to measure atmospheric pressure. Common types include mercury barometers, which measure...
Barometer cisternThe reservoir of mercury at the base of a mercury barometer, into which the open end of the evacuated glass...
Barometer elevationThe specific vertical height above a standard reference datum, usually mean sea level, at which a barometer...
BarometricRelating to or indicated by a barometer, an instrument used for measuring atmospheric pressure. The term...
Barometric characteristicA qualitative description of the recent trend and magnitude of atmospheric pressure changes, often observed...
Barometric constantA numerical value used in barometric formulas to relate atmospheric pressure to altitude, often derived from...
Barometric correction tableA table or graph of the small corrections that compensate for the instrumental errors of a mercury barometer...
Barometric correctionsAdjustments applied to a pressure reading from a barometer to account for systematic errors and produce a...
Barometric hypsometryA method of determining atmospheric pressure indirectly by measuring the temperature at which water boils...
Barometric pressureThe pressure of the atmosphere as indicated by a barometer.
Barometric rateThe speed and direction of change in atmospheric pressure over a specific period. This rate indicates whether...
Barometric reduction tableA chart or set of data used to calculate the sea-level pressure from a given station pressure. The reduction...
Barometric waveA propagating disturbance in atmospheric pressure, often associated with large-scale atmospheric phenomena...
BarometryThe scientific field concerned with the measurement and study of atmospheric pressure. This discipline...
BaromilA unit of length used to graduate the scale of a mercury barometer, equal to the height of mercury that...
BaroswitchA pressure-activated electrical switch that responds to changes in atmospheric pressure. It consists of an...
BarothermographA self-recording instrument that traces atmospheric pressure and temperature on one chart, combining an...
BarothermohygrographA meteorological instrument that automatically records atmospheric pressure, air temperature, and relative...
BarotropicDescribing an atmospheric state where surfaces of constant pressure are parallel to surfaces of constant...
Barotropic atmosphereAn atmospheric condition where surfaces of constant pressure are parallel to surfaces of constant density or...
Barotropic disturbanceAn atmospheric wave or perturbation in which surfaces of constant pressure are parallel to surfaces of...
Barotropic forecastA weather prediction derived from numerical models that assume a barotropic atmosphere, meaning that the wind...
Barotropic instabilityA type of hydrodynamic instability that arises in a fluid flow where the basic state is barotropic, meaning...
Barotropic modelA numerical model based on an idealised barotropic atmosphere, in which density depends on pressure alone and...
Barotropic pressure functionA scalar function of pressure in a barotropic fluid, defined as the integral of dp divided by density, whose...
Barotropic systemA weather system in which temperature and pressure surfaces are coincident, i.e., temperature is uniform (no...
Barotropic vorticity equationA simplified form of the vorticity equation that describes the evolution of absolute vorticity in a...
BarotropyA state in a fluid where surfaces of constant pressure are parallel to surfaces of constant density. In a...
BarrageIn hydrologic terms, any artificial obstruction placed in water to increase water level or divert it. Usually...
BarrierA large-scale topographic feature, such as a mountain range, that obstructs or redirects atmospheric flow...
Barrier icebergA very large, flat-topped iceberg that has calved from an ice shelf, characterized by its extensive...
Barrier jetA low-level, narrow band of strong winds that forms parallel to a mountain range or other topographic...
Barrier layerA layer in the upper ocean between the base of the shallow, salinity-stratified mixed layer and the top of...
Barrier theoryAn early theory of cyclone development proposed by Exner, in which a slow-moving mass of cold air lying in...
Bartel's rotation numberThe serial number assigned to 27-day rotation periods of solar and geophysical parameters. Rotation 1 in this...
BaryeA unit of pressure in the CGS (centimeter-gram-second) system of units, defined as one dyne per square...
Basal slidingThe movement of a glacier or ice sheet over its bed, lubricated by a thin layer of meltwater at the...
Base dataThose digital fields of reflectivity, mean radial velocity, and spectrum width data in spherical coordinates...
Base floodIn hydrologic terms, the national standard for floodplain management is the base, or one percent chance...
Base flowThe portion of streamflow that is sustained by the slow seepage of groundwater into a stream channel, rather...
Base level of erosionThe lowest elevation to which a river or stream can erode its channel. The ultimate base level for all river...
Base lineA line of known length between two observing points, used as the base for triangulation in meteorological...
Base mapA map that provides fundamental geographic information, such as topography, political boundaries...
Base productsThose products that present some representation of the base data. This representation may not necessarily be...
Base reflectivityBase Reflectivity is the default image. Taken from the lowest (½° elevation) slice, it is the primary image...
Base StationIn hydrologic terms, a computer which accepts radio signals from ALERT gaging sites, decodes the data, places...
Base widthThe time span of the direct runoff hydrograph, from the start of the rising limb to the point where...
BaseflowIn hydrologic terms, streamflow which results from precipitation that infiltrates into the soil and...
Baseflow recession curveA graphical representation showing the decline in streamflow over time during periods without precipitation...
Baseflow storageThe volume of water held in a catchment's subsurface, such as in soil and shallow aquifers, that is available...
Baseline checkA pre-launch test in which the temperature, humidity and pressure outputs of a radiosonde are compared with...
Baseline monitoringThe systematic, long-term measurement of atmospheric composition and physical parameters at locations...
Basic flowThe fundamental, often time-averaged or spatially averaged, component of a fluid flow upon which...
BasinAn area of land drained by a river and its tributaries, so that all surface runoff leaves through a single...
Basin boundaryThe topographic dividing line around the perimeter of a basin, beyond which overland flow (i.e.; runoff)...
Basin lagThe time interval between the center of mass of a rainfall event over a drainage basin and the resulting peak...
Basin outletThe lowest point in a drainage basin where all surface water collected within the basin exits, typically a...
Basin rechargeThe process by which water infiltrates the ground and replenishes groundwater reserves within a drainage...
Basin responseThe hydrological behavior of a drainage basin in reaction to a precipitation event, characterized by changes...
Basis functionsA set of linearly independent functions used to construct other functions within a given function space...
BathyA prefix derived from the Greek word for deep, used in scientific terms to denote depth or a relationship to...
BathymeterAn instrument used for measuring the depth of a body of water, such as an ocean, sea, or lake. Modern...
Bathymetric chartA type of map that illustrates the underwater topography of a lakebed, riverbed, or seafloor. It provides a...
BathymetryThe measurement of the depth of water in oceans, seas, or lakes, and the study of the underwater topography...
BathythermographAn oceanographic instrument designed to measure and record water temperature as a function of depth. It...
Bathythermograph gridA calibrated transparent overlay, marked with lines representing temperature and depth, used to interpret the...
Bathythermograph printA photographic print made from the smoked-glass slide of a mechanical bathythermograph, exposed together with...
Bathythermograph slideA smoked glass slide used in older mechanical bathythermographs to record temperature and depth data. As the...
BaudA unit of measure for symbol rate, representing the number of signaling events or symbol changes per second...
Bay iceSea ice that forms or accumulates within the sheltered waters of a bay or inlet. Its characteristics, such as...
Bay of Bengal WaterA distinct water mass found in the Bay of Bengal, characterized by its relatively low salinity due to...
BayamoA violent squall that blows from the land on the south coast of Cuba, especially near the Bight of Bayamo...
Bayesian methodA statistical approach that updates the probability for a hypothesis as more evidence or information becomes...
BCKGBacking- A counterclockwise shift in wind direction (for example, south winds shifting to the east).
BCMBecome
BCMNGBecoming
BDBlowing Dust
B-displayA type of radar display that presents target range on the vertical axis and azimuth angle on the horizontal...
Beach erosionThe movement of beach materials by some combination of high waves, currents and tides, or wind.
Beaded lightningA rare form of lightning that appears as a series of luminous segments or beads along the lightning channel...
BeamA directed emission of electromagnetic radiation, such as from a radar or lidar system, used to probe the...
Beam fillingAn effect in remote sensing where the volume sampled by a sensor's beam contains a mixture of different...
Beam swingingA technique used in Doppler radar systems, particularly wind profilers, to measure the three-dimensional wind...
Beam widthAngular width of antenna pattern. Usually that width where the power density is one-half that of the axis...
Beam windA wind that blows perpendicular to the course of a vessel or aircraft, striking it directly on its side. This...
BeamwidthThe angular width of a radar or lidar beam, defined as the angle between the half-power points of the main...
BearingThe horizontal direction from an observer or reference point to an object or phenomenon, measured clockwise...
Bear's cage[Slang], a region of storm-scale rotation, in a thunderstorm, which is wrapped in heavy precipitation. This...
BeatingThe process of sailing a vessel against the wind by tacking, which involves sailing at an angle into the wind...
Beaufort forceA numerical value on the Beaufort wind scale that quantifies wind speed based on observed sea conditions or...
Beaufort scaleThe Beaufort wind scale is a system used to estimate and report wind speeds when no measuring apparatus is...
Beaufort weather notationA system of single letters, devised by Francis Beaufort in the nineteenth century, for recording weather in a...
Beaufort wind scaleA system for estimating wind speed based on observed sea state or terrestrial effects. It categorizes wind...
Beaumont periodA 48-hour weather spell used to warn of potato blight, in which at least 46 of the 48 consecutive hourly...
Beaver('s) tail[Slang], a particular type of inflow band with a relatively broad, flat appearance suggestive of a beaver's...
Beavertail antennaA type of radar antenna that produces a fan-shaped beam, narrow in one dimension and broad in the...
Bed loadIn hydrologic terms, sand, silt, gravel, or soil and rock detritus carried by a stream on or immediately...
Beginning of freezupIn hydrologic terms, date on which ice forming a stable winter ice cover is first observed on the water...
Beginning of the breakupIn hydrologic terms, date of definite breaking, movement, or melting of ice cover or significant rise of...
Bellamy methodA method of computing horizontal divergence and vorticity from wind observations at three stations forming a...
Below minimumsA condition in aviation meteorology where reported weather conditions, such as visibility or cloud ceiling...
Belt of fluctuationA zone of the subsurface between the highest and lowest levels reached by the water table, within which the...
Beltrami flowA type of fluid flow where the velocity vector is everywhere parallel to its own vorticity vector. This means...
Bemporad's formulaA mathematical expression used to calculate the optical air mass, which represents the effective path length...
Bénard cellA pattern of convective cells that forms in a fluid layer heated from below and cooled from above, or when a...
BenchmarkA reference point or standard used for comparison in meteorological measurements or models. It provides a...
Benchmark stationA long-term, stable meteorological or climatological observing site used as a reference standard for...
Benguela CurrentA broad, cold ocean current that flows northward along the west coast of Southern Africa, originating from...
Bent-back occlusionA type of occluded front where the cold front wraps around the low-pressure center and extends backward...
Bentu de soliA local name for the east wind on the coast of Sardinia, from Sardinian words meaning wind of the sun...
BenzeneA volatile organic compound (VOC) with the chemical formula C6H6, consisting of a six-carbon ring structure...
Benzo-a-pyreneA polycyclic aromatic hydrocarbon (PAH) formed during the incomplete combustion of organic matter. It is a...
BergA short name for an iceberg, a large mass of floating freshwater ice that has broken off a glacier or ice...
Berg windA hot, dry wind that descends from the interior plateau of South Africa towards the coast. It forms when...
Bergeron classificationA system for classifying air masses based on their temperature and moisture characteristics, developed by Tor...
Bergeron processThe process by which ice crystals in a cloud grow at the expense of supercooled liquid water droplets.
Bergeron-Findeisen processThe primary mechanism for precipitation formation in cold clouds, where both supercooled water droplets and...
Bergy bitA piece of floating glacier ice larger than a growler and smaller than an iceberg, standing roughly 1 to 5 m...
Bering Slope CurrentA northwestward boundary current along the continental slope of the eastern Bering Sea, formed where the...
Bermuda highA semi-permanent subtropical high-pressure system located in the North Atlantic Ocean, typically centered...
Bernal-Fowler rulesA set of two principles that describe the positions of hydrogen atoms within the crystalline structure of...
Bernoulli's theoremA principle in fluid dynamics stating that for an incompressible, inviscid fluid in steady flow, an increase...
Best numberA dimensionless quantity used to characterize the terminal settling velocity of spherical particles in a...
Best trackA post-analysis re-evaluation of a tropical cyclone's path and intensity, based on all available...
Beta driftThe movement of a tropical cyclone due to the variation of the Coriolis parameter with latitude, known as the...
Beta effectThe variation of the Coriolis parameter with latitude, which influences the dynamics of large-scale...
Beta gyreA pair of counter-rotating circulations, one cyclonic and one anticyclonic, that form on either side of a...
Beta particleA high-energy electron or positron emitted from an atomic nucleus during radioactive decay, specifically beta...
Beta planeAn approximation to a rotating spherical Earth in which motion is treated on a flat plane and the Coriolis...
Beta rayA stream of beta particles, which are high-energy electrons or positrons, emitted during radioactive decay...
Beta spiralA method devised by Stommel and Schott for inferring absolute geostrophic velocity in the ocean from density...
BFRBefore
BGNBegin
BHNDBehind
BIASA systematic difference between an estimate of and the true value of a parameter.
Bidirectional reflectance distribution functionA function giving the ratio of the radiance reflected from a surface into one direction to the irradiance...
Bidirectional reflectance factorThe ratio of the radiance reflected from a surface in a specific direction to the radiance that would be...
Bidirectional reflection functionA mathematical function that describes how light is reflected from an opaque surface, accounting for the...
Biennial iceSea ice that has survived one melt season and is in its second year of growth. It is thicker and stronger...
Biennial wind oscillationA quasi-periodic variation in atmospheric winds, particularly in the stratosphere, with a cycle length of...
Bifilar electrometerA sensitive electrostatic instrument in which two fine conducting filaments, stretched side by side, repel...
Bihemispherical reflectanceThe ratio of the radiant flux reflected by a surface to the radiant flux incident upon it, integrated over...
Billow cirrus cloudsHigh-level clouds characterized by wave-like or ripple patterns, often appearing as parallel bands or rolls...
Billow cloudA distinctive cloud formation characterized by parallel, wave-like rolls that appear stacked or layered in...
Billow waveAn atmospheric wave characterized by a series of parallel, cresting rolls that form at the interface between...
Bimetallic stripA temperature-sensitive element constructed from two different metals bonded together, each possessing a...
Bimetallic thermometerA temperature-measuring device constructed from two strips of different metals, such as steel and copper...
Bimodal spectrumA frequency distribution or spectrum that exhibits two distinct peaks or modes, indicating the presence of...
BINRadar sample volume.
Binary codeA system for representing data using only two symbols, typically 0 and 1, which correspond to on/off or...
Binary cyclonesA pair of tropical cyclones or extratropical cyclones that are close enough to each other to interact, often...
Binomial distributionA discrete probability distribution that describes the number of successes in a fixed number of independent...
BINOVCBreaks in Overcast
Bio-assayA procedure for determining the concentration or potency of a substance by measuring its effect on a living...
Biochemical oxygen demandA measure of the amount of dissolved oxygen consumed by aerobic microorganisms in water as they decompose...
BioclimatographA graphical representation illustrating the relationship between climatic conditions and the distribution of...
BioclimatologyThe scientific study of the interactions between living organisms and their atmospheric environment, focusing...
Biogenic ice nucleusA microscopic particle of biological origin, such as bacteria, fungi, or pollen, that can initiate the...
Biogenic trace gasesGaseous compounds present in the atmosphere in low concentrations that originate from biological sources...
Biogeochemical cycleThe pathway by which a chemical element or compound moves through both biotic (living) and abiotic...
Biomass burningThe combustion of living or dead organic matter, such as forests, grasslands, and agricultural residues. This...
BiometeorologyThe interdisciplinary scientific field that investigates the interactions between the atmosphere and living...
BiosphereThe global sum of all ecosystems, encompassing all life on Earth and the regions it inhabits. This includes...
Biosphere reservesProtected areas designated under the UNESCO Man and the Biosphere (MAB) Programme to serve as living...
Bipolar patternA spatial pattern in cloud-to-ground lightning locations in which flashes of opposite polarity cluster in...
Birainy climateA climate regime characterized by two distinct rainy seasons separated by two relatively dry periods within a...
Bird burstA characteristic pattern on a weather radar display caused by a large flock of birds taking off at once...
BirefringenceAn optical property of anisotropic materials in which the refractive index depends on polarization and...
BiseA cold, dry northerly or northeasterly wind that blows across Switzerland and France, particularly in the...
Bishop's ringA large, whitish or bluish-white halo observed around the sun or moon, often with a brownish-red outer...
BistaticDescribing a remote sensing configuration where the transmitter and receiver are situated at separate...
Bistatic radarA radar system in which the transmitting and receiving antennas are separated by a considerable distance...
BitA binary digit, the smallest unit of data in computing and digital communications, representing either a 0 or...
Bit rateThe number of bits of data transmitted or processed per unit of time, a fundamental measure of data transfer...
BivaneA meteorological instrument designed to measure both horizontal and vertical components of wind direction. It...
BKNBroken
BLAbbreviation for Boundary Layer; a layer of air adjacent to a bounding surface. Specifically, the term most...
Black blizzardA severe dust storm, particularly common in the Great Plains of the United States during the 1930s Dust Bowl...
Black fogA type of fog that appears dark due to the presence of a high concentration of smoke, soot, or industrial...
Black frostA type of frost that occurs when the air temperature drops below freezing, but the humidity is too low for...
Black iceA thin coating of ice on a surface, especially a road or pavement, that is transparent and appears black...
Black northeasterA severe weather phenomenon characterized by strong northeasterly winds, heavy rainfall, and rough seas...
Black squallA squall that arrives with dark, heavy cloud and precipitation, named for the black appearance of the cloud...
Black stormA severe dust storm characterized by extremely dark skies due to the vast amount of suspended soil particles...
Black stratusA thin low stratus or stratocumulus layer that looks darker than the snow-covered ground around it on...
BlackbodyA theoretical object that perfectly absorbs all electromagnetic energy striking its surface, regardless of...
Blackbody radiationElectromagnetic radiation emitted by an idealized physical body that absorbs all incident electromagnetic...
Blackbody temperatureThe temperature that a blackbody would have if it emitted the same amount of radiation as a given object...
Black-bulb thermometerA thermometer with its bulb painted black and often enclosed in a vacuum tube, designed to measure radiant...
Blackthorn winterA period of cold weather that occurs in early spring in the British Isles, coinciding with the blossoming of...
BLDBuild
BLDUPBuildup
Blending heightThe height above a heterogeneous surface at which the flow no longer varies horizontally with the individual...
Blind rollersA long ocean swell that rises steeply, almost to the point of breaking, as it passes over a shoal or runs...
BlinkA luminous reflection on the underside of clouds, caused by light reflected from a snow or ice-covered...
BlipA transient, often small, echo or signal appearing on a radar screen, indicating the presence of a target...
BlizzardA severe winter storm characterized by heavy snowfall, strong winds, and extremely low visibility. Official...
Blizzard warningIssued for winter storms with sustained or frequent winds of 35 mph or higher with considerable falling...
BLOBelow
Blocked flowFlow approaching a mountain barrier that is too weak or too stable to be carried over the barrier.
BlockingA large-scale atmospheric circulation pattern characterized by a persistent, quasi-stationary high-pressure...
Blocking highA large, quasi-stationary high-pressure system that disrupts the typical zonal flow of the westerlies...
Blood rainPrecipitation that appears reddish due to the presence of dust or sand particles suspended within the...
BlowingA descriptor used to amplify observed weather phenomena whenever the phenomena are raised to a height of 6...
Blowing dustDust or sand particles lifted from the ground by wind to heights of two meters or more, reducing horizontal...
Blowing dust advisoryThis product is issued when widespread, synoptically driven blowing dust is reducing visibilities to 1 mile...
Blowing dust or sandStrong winds over dry ground, that has little or no vegetation, can lift particles of dust or sand into the...
Blowing dust warningThis product is issued when widespread, synoptically driven blowing dust is reducing visibilities to ¼ mile...
Blowing sandSand particles lifted from the ground by wind to a height of at least two meters, impairing horizontal...
Blowing snowSnow particles lifted from the ground by wind to a height of two meters or more, reducing horizontal...
Blowing snow advisoryIssued when wind driven snow reduces surface visibility, possibly, hampering traveling. Blowing snow may be...
Blowing sprayWater droplets lifted from the surface of a large body of water, such as an ocean or large lake, by strong...
Blue flashA rare optical phenomenon observed at sunrise or sunset, appearing as a momentary blue or green flash of...
Blue iceGlacial ice that appears blue due to its density and the way it absorbs and scatters light. As snow compacts...
Blue jetsUpward-propagating electrical discharges that emanate from the top of active thunderstorms into the...
Blue moonThe second full moon occurring within a single calendar month, or the third full moon in an astronomical...
Blue noiseA type of signal or spatial pattern whose power spectrum has minimal energy at low frequencies and increasing...
Blue watch or blue box[Slang], a severe thunderstorm watch.
Blue-ice areaA region on an ice sheet or glacier where snow accumulation is negative due to wind scouring and sublimation...
BlunkA sudden squall at sea, a stormy gust that blows up without warning and can hit a ship hard. The word belongs...
BlusterySame as Breezy; 15 to 25 mph winds.
BLVbefore
BLZDBlizzard- A blizzard means that the following conditions are expected to prevail for a period of 3 hours or...
BNBlowing Sand
BNDRYBoundary
Bodily tidesThe deformation of the solid Earth caused by the gravitational forces of the Moon and the Sun. These forces...
Body wavesSeismic waves that travel through the interior of the Earth, as opposed to surface waves that travel along...
BogA wetland ecosystem characterized by acidic, nutrient-poor soil and a thick layer of peat, primarily composed...
Bogus observationAn artificial observation constructed by analysts or by a program and inserted into an objective analysis or...
Bogus vortexAn artificially generated cyclonic circulation inserted into the initial conditions of a numerical weather...
BohorokA warm, dry, and gusty downslope wind on the leeward side of the Barisan Mountains in Sumatra, Indonesia...
BoilTo undergo a phase transition from liquid to gas, characterized by the formation of bubbles within the liquid...
Boiling pointThe temperature at which a liquid's vapor pressure equals the external pressure exerted on it, causing the...
Bolling-AllerodA relatively warm and moist interstadial period that occurred during the last deglaciation, marking a...
BologramA graphical representation of the distribution of radiant energy across different wavelengths, typically used...
BolometerAn instrument designed to measure the intensity of radiant energy by detecting the heat produced when...
Boltzmann's constantA fundamental physical constant that relates the average kinetic energy of particles in a gas to the absolute...
BombPopular expression of a rapid intensification of a cyclone (low pressure) with surface pressure expected to...
Bomb cycloneA rapidly intensifying extratropical cyclone that experiences a dramatic drop in central atmospheric pressure...
Bond energyThe amount of energy required to break a specific chemical bond between two atoms in a molecule, or the...
Book-end vorticesA pair of counter-rotating vortices at the two ends of a bow echo or squall line, with a cyclonic one at the...
BoraA cold, dry, and often gusty katabatic wind that descends from mountainous regions towards the coast...
Bora fogA dense fog of fine water droplets that forms when a strong bora wind tears spray from the sea surface and...
Bora scuraA specific type of bora wind that is accompanied by cloudy skies and precipitation, contrasting with the...
Border iceIn hydrologic terms, an ice sheet in the form of a long border attached to the bank or shore.; shore ice.
BoreA rapidly propagating wave or surge that moves through a fluid, often characterized by a distinct leading...
BorealDescribing the northern climatic zone characterized by long, cold winters and short, cool summers. This...
Boreal forestA vast biome characterized by coniferous trees, primarily spruce, fir, and pine, adapted to cold climates. It...
Boreal woodlandAn open-canopy vegetation type of subarctic and subalpine habitats, with sparse stands of short needleleaf or...
Boreal zoneThe biome situated in high northern latitudes, characterized by coniferous forests dominated by pines...
BoreasThe personification of the north wind in ancient Greek mythology, often depicted as a winged, bearded old...
BorinoA light and gentle form of the bora wind, occurring along the Adriatic coast, especially near Trieste. Unlike...
BornanA violent squall wind on Lake Geneva that blows from the Dranse valley on the Savoy shore out over the lake...
Bottlinger's ringsA rare halo in the form of a small ellipse around the sun or, more often noticed, around the subsun, seen...
Bottom currentA flow of water moving along the floor of an ocean, sea, or lake. These currents are driven by density...
Bottom frictionThe resistive force exerted by the seafloor or land surface on the overlying fluid, such as water or air, as...
Bottom temperatureThe temperature of the water layer immediately adjacent to the bed of an ocean, sea, or lake. This...
Bottom waterThe densest water mass lying on the floor of an ocean basin, formed in polar regions where surface water made...
Bouguer-Lambert lawA principle describing the attenuation of light as it passes through an absorbing medium. It states that the...
Bouguer's lawA principle describing the attenuation of light as it passes through an absorbing medium, stating that the...
Boundary conditionsThe set of physical constraints or values specified at the edges or limits of a computational domain in...
Boundary currentsStrong, narrow ocean currents that flow along the eastern or western edges of ocean basins, driven by wind...
Boundary layerThe lowest part of the troposphere, directly influenced by the Earth's surface and responding to surface...
Boundary layer radarA specialized radar system designed to observe atmospheric phenomena within the planetary boundary layer...
Boundary layer separationA phenomenon where a fluid flow detaches from a solid surface, typically occurring when the fluid encounters...
Boundary mixingTurbulent mixing of water properties near the boundaries of a stratified ocean, such as the sloping seafloor...
Boundary-value problemA mathematical problem involving a differential equation where the solution is sought within a domain...
Bounded weak echo regionA radar signature in a supercell, seen as a vertical column of weak reflectivity at low and mid levels that...
Bourdon tubeA pressure-sensing element consisting of a flattened, curved metal tube that tends to straighten out when...
Boussinesq approximationA simplification used in fluid dynamics for flows where density variations are small, except when they are...
Boussinesq equationA nonlinear partial differential equation, or system of equations, for long waves in shallow water that...
Boussinesq numberA dimensionless ratio of the characteristic vertical length scale of a low-Mach-number flow to the scale...
BOVCBase of Overcast
Bow echoA radar reflectivity signature characterized by an arc-shaped line of thunderstorms, indicating strong...
Bowen ratioThe ratio of sensible heat flux to latent heat flux from a surface, representing the partitioning of...
Box modelA computer model used to calculate air pollution concentrations. A box model is based on the assumption that...
Box modelsSimplified conceptual models that divide a system, such as the atmosphere or an ocean basin, into a series of...
Boyden indexA stability index for thunderstorm forecasting, devised by Boyden in the United Kingdom, computed from the...
Boyle's lawThe gas law stating that for a fixed mass of ideal gas at constant temperature, pressure and volume are...
Boys cameraA specialized high-speed photographic instrument designed to resolve the temporal structure of a lightning...
BPI panAn instrument for measuring the rate of water evaporation, developed by the U.S. Bureau of Plant Industry. It...
BRMist
Brackish iceIn hydrologic terms, ice formed from brackish water.
Brackish waterWater that has a salinity level between that of freshwater and seawater, typically found in estuaries...
Bragg scatteringThe coherent backscattering of waves from a periodic spatial structure whose spacing is half the wavelength...
Braided streamIn hydrologic terms, characterized by successive division and rejoining of streamflow with accompanying...
BrashAccumulations of fragmented ice pieces, smaller than 2 meters (6.6 feet) across, resulting from the breaking...
Brash iceIn hydrologic terms, accumulation of floating ice made up of fragments not more than 2 meters across; the...
Brazil CurrentA warm ocean current that flows southward along the southeastern coast of South America, originating from the...
BRDBorder
BreachIn hydrologic terms, the failed opening in a dam.
Breadth-first searchAn algorithm for traversing or searching tree or graph data structures, which are common in atmospheric...
BreakA temporary period of improved weather conditions, such as clearing skies or the cessation of precipitation...
Breakdown fieldThe minimum electric field strength required to cause electrical discharge or breakdown in a gas, such as...
BreakerA surface ocean wave that collapses or 'breaks' as it approaches a coastline or shallow water, typically due...
Breaker depthThe water depth at which an ocean wave begins to break, transforming from a smooth swell into a turbulent...
Breakers, see Breaker
Breaking-drop theoryA theory of thunderstorm electrification based on the Lenard effect, in which the breakup of large water...
Breaks in overcastPeriods of partial clearing or visible patches of sky within an otherwise continuous layer of overcast cloud...
Breakthrough curveA graph illustrating the concentration of a substance at the outlet of a system as a function of time, after...
BreakupThe process by which a continuous ice cover, such as on a lake, river, or sea, disintegrates into smaller...
Breakup dateIn hydrologic terms, date on which a body of water is first observed to be entirely clear of ice and remains...
Breakup jamIn hydrologic terms, an ice jam that occurs as a result of the accumulation of broken ice pieces.
Breakup periodIn hydrologic terms, the period of disintegration of an ice cover.
Breakup seasonThe annual period in spring during which ice on rivers, lakes, and coastal seas fractures, melts, and clears...
BreakwaterA coastal structure built offshore or perpendicular to the shore to protect a harbor, anchorage, or coastline...
Bred modesPerturbations that grow rapidly within a numerical weather prediction model, identified through a breeding...
Bred vectorsPerturbations to an atmospheric state that are repeatedly evolved forward in time by a numerical weather...
Breeding methodA technique for generating the initial perturbations used in ensemble weather forecasting to represent...
BreezeA light wind, typically characterized by a gentle and pleasant flow of air. In the Beaufort scale, a breeze...
Breezy15 to 25 mph winds
BremsstrahlungElectromagnetic radiation generated when a charged particle, such as an electron, is decelerated or deflected...
BrevaA local thermal wind that blows across Lake Como in northern Italy, typically from the south during the...
Brewer-Dobson circulationA large-scale pattern of atmospheric circulation that transports air from the tropical troposphere into the...
Brewster pointOne of the neutral points in the polarization pattern of skylight, a point where the scattered light is...
BRFBrief
BrickfielderA hot, dry and dusty north wind that blows from the interior of Australia toward the southern coast, notably...
Bridled-cup anemometerA cup anemometer whose multi-cup rotor, mounted on a vertical axis, turns against restraining springs, so the...
BriefingA concise presentation of current and forecast meteorological conditions, provided to individuals or groups...
Brier scoreA verification measure used to assess the accuracy of probabilistic forecasts for binary events, such as the...
Bright bandA distinct horizontal layer of enhanced radar reflectivity observed in precipitation, typically located just...
Bright segmentA faintly glowing band of sky above the horizon after sunset or before sunrise, also called the twilight arch...
Bright sunshineDirect solar radiation intense enough to cast a distinct shadow, as measured by a sunshine recorder. This...
Bright Surge on the DiskIn solar-terrestrial terms, a bright gaseous stream (surge) emanating from the chromosphere.
Bright Surge on the LimbIn solar-terrestrial terms, a large gaseous stream (surge) that moves outward more than 0.15 solar radius...
BrightnessThe apparent radiance of an object as measured by a remote sensing instrument, particularly a satellite...
Brightness temperatureThe temperature a blackbody would have to radiate with the same intensity at a given wavelength as the...
BrineWater saturated or nearly saturated with dissolved salts, primarily sodium chloride, resulting in a high...
Brine slushSlush that cannot quite turn to ice because of its high salt content, found most often between young sea ice...
BrisaA regional name for a prevailing seasonal wind: the northeast wind along the coast of South America and the...
Brisk15 to 25 mph winds
Brisk wind advisoryA Small Craft Advisory issued by the National Weather Service for ice-covered waters.
BrisoteA Cuban name for the northeast trade wind when it blows more strongly than usual. The trade wind is the...
British thermal unitA unit of heat energy in the imperial system, representing the quantity of thermal energy needed to increase...
BRKBreak
BRN(Bulk Richardson Number) A non-dimensional number relating vertical stability and vertical shear (generally...
BroadbandA method of signaling in which multiple signals share the bandwidth of the transmission by the subdivision of...
Broadband radiationElectromagnetic radiation integrated across a wide portion of the electromagnetic spectrum, encompassing a...
Broad-crested weirA hydraulic structure used to measure the flow rate of water in open channels, characterized by a crest that...
Brocken specterAn optical phenomenon sometimes occurring at high altitudes when the image of an observer placed between the...
Brocken spectreAn optical phenomenon in which an observer's magnified shadow is cast upon a cloud or fog bank opposite the...
BrokenA sky condition where between 5/8 and 7/8 of the sky is covered by clouds. This classification is used in...
Broken levelA layer of the atmosphere with 5/8 to 7/8 sky cover (cloud cover).
Bromine compoundsChemical substances containing bromine that are present in the atmosphere, playing a role in atmospheric...
BrontidesLow-frequency rumbling sounds, often described as distant thunder or cannon fire, that are heard without any...
BrontometerAn instrument designed to detect and record atmospheric phenomena associated with thunderstorms, such as...
Brown cloudA large-scale atmospheric haze layer, primarily composed of airborne particulate matter and pollutants such...
Brown snowSnowfall that appears discolored due to the incorporation of dust, soot, or other particulate matter from the...
Brownian motionThe random, erratic movement of microscopic particles suspended in a fluid, resulting from their collision...
Brownian rotationThe random, erratic rotational motion of an aerosol or other small particle suspended in a fluid, caused by...
BrubuA strong, dry, and gusty easterly wind that occurs on the island of Sulawesi, Indonesia. This local wind is a...
Brückner cycleA proposed quasi-periodic oscillation in climate, characterized by alternating periods of cooler, wetter...
BrumaA haze that appears in the afternoon on the coast of Chile when marine air moves onto the land. The name is...
Brunt-Väisälä frequencyThe natural oscillation frequency of a parcel of fluid displaced vertically within a stably stratified...
BrüschaA northwest wind in the Bergell Valley, known in Italian as Val Bregaglia, in the canton of Graubünden in...
BSBlowing Snow
BTRBetter
BTWNBetween
Bubble burstingThe process by which a gas bubble at a liquid's surface ruptures, ejecting tiny droplets into the air. In...
Bubble gaugeA type of water level measuring instrument that determines depth by sensing the pressure required to force...
Bubble highA small high-pressure area with its own anticyclonic circulation, roughly 80 to 480 km across, that is often...
Bubble nucleusA microscopic particle or cavity within a liquid that serves as a site for the formation and growth of a gas...
Bubbler gageIn hydrologic terms, a water stage recording device that is capable of attaching to a LARC for data...
BubblesSmall pockets of gas enclosed within a liquid or solid, typically spherical in shape. In atmospheric science...
Bubbly iceIce that contains numerous small air pockets or bubbles trapped within its structure. This type of ice forms...
Bucket temperatureThe temperature of the sea surface measured by collecting a sample of seawater in a bucket and then inserting...
Bucket thermometerA simple thermometer used to measure the temperature of water collected in a bucket, typically from the sea...
Budget yearThe one-year period used in glacier mass balance accounting, beginning at the start of the accumulation...
Budgets of atmospheric speciesA quantitative accounting of the sources, sinks, and transport processes that control the concentration of a...
Buffer factorThe ratio of the fractional change in the CO2 partial pressure of seawater to the fractional change in its...
BUFKITA software tool used by forecasters to examine the vertical profile and other aspects of the atmosphere.
Buildup indexA numerical index used in fire weather forecasting to estimate the cumulative effect of drying on forest...
Bulk averageAn average value of a physical property, such as temperature or velocity, calculated over a defined volume or...
Bulk heat fluxThe total rate of heat transfer across an interface, such as the air-sea interface, calculated using...
Bulk methodA simplified approach to parameterizing turbulent fluxes of heat, moisture, and momentum between the...
Bulk mixed layer modelA simplified conceptual model that represents a well-mixed layer of fluid, such as the oceanic mixed layer or...
Bulk Richardson numberA dimensionless stability measure computed from differences across a layer rather than from local gradients...
Bulk transfer coefficientA dimensionless parameter that quantifies the efficiency of turbulent exchange processes, such as momentum...
Bulk transfer lawA set of empirical relationships used to estimate turbulent fluxes of momentum, heat, and moisture between...
Bulk turbulence scaleA scale for the nocturnal stable boundary layer equal to its bulk depth scale divided by the surface...
Bull's eye squallA squall that springs up in otherwise fair weather, particularly off the coast of South Africa. It takes its...
BummockA downward projection from the underside of a sea ice cover, formed by the crushing and piling of ice under...
BumpinessA qualitative description of atmospheric turbulence experienced by aircraft, resulting in irregular vertical...
BuoyA floating platform, either moored or drifting, equipped with sensors to collect and transmit meteorological...
BuoyancyThe upward force exerted by a fluid that opposes the weight of an immersed object, or in atmospheric science...
Buoyancy fluxThe rate at which buoyant energy is transferred vertically through a fluid, typically in the atmospheric...
Buoyancy frequencyThe natural oscillation frequency of a fluid parcel displaced vertically in a stably stratified fluid, also...
Buoyancy length scaleA characteristic vertical length over which buoyancy forces significantly influence fluid motion...
Buoyancy subrangeA specific range of eddy sizes within a turbulent flow where buoyancy forces significantly influence the...
Buoyancy velocityA velocity scale for buoyancy-driven turbulence, formed from the buoyancy flux B and a height z as the cube...
Buoyancy waveA type of internal gravity wave that occurs in a stably stratified fluid, where buoyancy acts as the...
Buoyancy wavenumberThe wavenumber in stably stratified turbulence that is set by the buoyancy frequency divided by the...
Buoyant instabilityA condition in the atmosphere where an air parcel, if displaced vertically, becomes warmer and less dense...
Buoyant subrangeA range of eddy sizes within a turbulent flow where buoyancy forces are a dominant factor in the energy...
BuranA strong, cold northeasterly wind that blows across the steppes of Siberia and Central Asia, particularly in...
BurgaA storm of strong wind with sleet or driven snow in Alaska, also spelled boorga, from the Russian word for a...
Burger numberA dimensionless parameter in geophysical fluid dynamics that compares the relative strength of stratification...
Burger's vortexA theoretical model of a steady, axisymmetric vortex that includes the effects of both viscosity and axial...
Burn areaThe total extent of land surface that has been affected by fire, typically measured after a wildfire event...
Burn offTo dissipate or clear away fog, mist, or low clouds due to solar heating of the Earth's surface. As the sun...
Burning indexA numerical rating that indicates the potential for fire behavior in a given area, considering factors like...
BurstIn solar-terrestrial terms, a transient enhancement of the solar radio emission, usually associated with an...
BursterA sudden, strong squall or gust of wind, often associated with a cold front or thunderstorm, particularly in...
Business as usualA scenario or projection in climate modeling that assumes no new policies or actions are taken to mitigate...
Businger-Dyer relationshipA set of empirical formulas describing the vertical profiles of mean wind speed, temperature, and humidity...
BustSlang for an inaccurate forecast, especially one where significant weather (e.g., heavy snowfall) is...
ButadieneA highly reactive volatile organic compound (VOC) present in the atmosphere primarily as a result of...
Buttress damButtress dams are comprised of reinforced masonry or stonework built against concrete. They are usually in...
Buys Ballot's lawA fundamental principle in meteorology that describes the relationship between wind direction and pressure...
BWERAbbreviation for Bounded Weak Echo Region; a radar signature within a thunderstorm characterized by a local...
BYDBeyond

491 of 10,702 terms in Meteorology and atmospheric science terminology (MLC-0110). Request the full dataset.