- A rubber seal used around stems of some valves to prevent water from leaking past.
- Browse Related Terms: Bonnet, Butterfly valve, Conifers, Fixed cone valve (Howell Bunger valve), Gate valve, Hollow-jet valve, Howell Bunger valve., Needle valve, O-ring, Petcock, Tube valve, Valve
All > Science > Energy > Renewable Energy > Solar Energy
- See ozone
- Browse Related Terms: Hydrofluorocarbon (HFC), Nitrogen dioxide (NO2), Nitrogen Oxides (NOx), NO2, NOx, O3, Ozone (O3), Volatile organic compound (VOC)
- Loosely woven hemp rope that has been treated with oil or other waterproofing agent; it is used to caulk joints in a bell and spigot pipe and fittings.
- Browse Related Terms: Class (pipe and fittings), Hub, Oakum, Sewer tile, Spigot, Standpipe, Surge chamber
All > Science > Energy > Renewable Energy > Solar Energy
- An isolated, fertile tract or green locality in a desert region, made so by the presence of water. See also Palm oasis
- Browse Related Terms: arid, Desert, Mantle hot spot, Mesic habitat, OASIS, Prehistoric resources, Rain shadow effect, Semi-arid, Shadow zone, Shrink-swell potential, Upper-air sounding
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- A species that depends completely upon habitat along a body of water.
- Browse Related Terms: Breeding potential, Endangered species, Endangered species act (ESA), ESA, Exotic species, Extirpated species, Fishery, Indicator, Indigenous, Microclimate, Obligate riparian species, Relict, Threatened, Threatened species
All > Science > Energy > Renewable Energy > Solar Energy
- Restricted to a particular condition of life; for example, dependent on a particular habitat to be able to breed. See also Riparian obligate species; Sand dune obligate species
- Browse Related Terms: Carrying Capacity, Compensation, Desert focal bird species, Ecological resources, Endangered Species Act of 1973 (ESA), fragmentation, Fragmentation of habitat, Habitat degradation, Obligate species, Riparian obligate species, Sand dune obligate species, Shrub-steppe, Shrubsteppe obligate, Snag, steppe, Wildlife corridor, Xeric (habitat)
All > Science > Weather > Climate Change
the tilt of the earth's axis of rotation, currently 23.4 degrees.
- Browse Related Terms: Arctic high, Eccentricity, Equinox, obliquity, orbital cycles, Precession, precession (of the equinoxes), Spring equinox
Observation(s)
- Browse Related Terms: AMOS, Blowing, Cooperative Observer, GoMoos, Hourly Precipitation Data (HPD), Isochrone, Mesonet, Meteogram, Nadir, OBS, parameter, Rawinsonde Observation, Reconnaissance Code, report, Station Model, Upper Level
Obscure
- Browse Related Terms: BASE DATA, BASE PRODUCTS, Base Reflectivity, Layer Composite Reflectivity Average, Layer Composite Reflectivity Maximum, OBSC, Radar Range, Range, Reflectivity Cross Section, Severe Weather Analysis, Spectrum Width Cross Section, Storm Relative Mean Radial Velocity Map, Storm Relative Mean Radial Velocity Regi, Storm Tracking Information, VAD, Weak Echo Region
Any atmospheric phenomenon, except clouds, that restricts vertical visibility (e.g., dust, rain, snow, etc.).
- Browse Related Terms: Condensation Funnel, D, Debris Cloud, Dry Microburst, Dust Devil, Dust Plume, Dust Whirl, funnel cloud, Gunge, Landspout, Multiple Vortex Tornado, Obscuration, Obscuring Phenomena, ROTG, SUF, Tornado, Waterspout, Whirlwind
Any atmospheric phenomenon, except clouds, that restricts vertical visibility (e.g., dust, rain, snow, etc.).
- Browse Related Terms: Condensation Funnel, D, Debris Cloud, Dry Microburst, Dust Devil, Dust Plume, Dust Whirl, funnel cloud, Gunge, Landspout, Multiple Vortex Tornado, Obscuration, Obscuring Phenomena, ROTG, SUF, Tornado, Waterspout, Whirlwind
All > Science > Weather > Climate Change
Observation A weather or meteorological observation is an evaluation of one or more meteorological elements that describes the state of the atmosphere either at the Earth's surface or aloft.
- Browse Related Terms: analysis, Atmospheric phenomenon, Error, Global Observing System, Observation, Observational network, Past weather, Polar explorer, Present weather, Pressure Tendency, Sea Level Pressure, single-column modeling (SCM), stable state, station pressure, Surface observation, surface weather chart, Synoptic analysis, Synoptic chart, Synoptic code, Synoptic hour, Synoptic meteorology, Synoptic weather observation, tree rings, Upper air observation
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- A hole used to observe the ground-water surface at atmospheric pressure within soil or rock.
A non-pumping well used for observing the elevation of the water table or piezometric surface.
- Browse Related Terms: Artesian Well, Creep, Earth pressure, Isochrome, Liquefaction, Observation well, Pascal (Pa), Phreatic surface, Swell pressure, Triaxial shear test
In hydrologic terms, a non-pumping well used for observing the elevation of the water table or piezometric surface
All > Science > Weather > Climate Change
Observational network A group of stations (surface meteorological, upper-air, or other stations) spread over a given area for making regular observations.
- Browse Related Terms: analysis, Atmospheric phenomenon, Error, Global Observing System, Observation, Observational network, Past weather, Polar explorer, Present weather, Pressure Tendency, Sea Level Pressure, single-column modeling (SCM), stable state, station pressure, Surface observation, surface weather chart, Synoptic analysis, Synoptic chart, Synoptic code, Synoptic hour, Synoptic meteorology, Synoptic weather observation, tree rings, Upper air observation
All > Science > Astronomy > Astrophysics
The flux due to a light emitting object measured at the observer (in most cases, at the earth or a satellite). Observed brightness is proportional to 1 divided by the distance to the object squared. The full moon has a greater observed brightness than the star, Vega, even though Vega has a greater luminosity.
- Browse Related Terms: Angular Size, Apparent luminosities, Constant of Proportionality, Dark Matter, Flux, Heavenly Bodies, Intrinsic Luminosity, Inverse Square, Luminosity, Main Sequence Star, Observed Brightness, Parallax, Parsec, Relative Brightness, Standard Candle, Type Ia Supernova, Variable Stars
All > Science > Energy > Renewable Energy > Solar Energy
A black or dark-colored volcanic glass.
- Browse Related Terms: Andesite, Aquifer-volcanic rock, Basalt, Dome, volcanic, Obsidian, Rhyolite, Rhyolitic domes, Scoria, Tertiary volcanics (Tv), Tuff, Vent, Volcanic vent, Volcanic-rock aquifer
All > Science > Weather > Climate Change
A composite of two fronts, formed as a cold front overtakes a warm or quasi-stationary front. Two types of occlusions can form depending on the relative coldness of the air behind the cold front to the air ahead of the warm or stationary front. A cold occlusion results when the coldest air is behind the cold front and a warm occlusion results when the coldest air is ahead of the warm front.
- Browse Related Terms: Advection fog, arctic air, Arctic air mass, Arctic front, Arctic Sea Smoke, cold front, contrail (condensation trail), front, front (or frontal zone), frontal inversion, Occluded Front, Polar low, Sea smoke, stationary pressure, Vortex, Warm front
A composite of two fronts, formed as a cold front overtakes a warm or quasi-stationary front. Two types of occlusions can form depending on the relative coldness of the air behind the cold front to the air ahead of the warm or stationary front. A cold occlusion results when the coldest air is behind the cold front and a warm occlusion results when the coldest air is ahead of the warm front.
A mesocyclone in which air from the rear-flank downdraft has completely enveloped the circulation at low levels, cutting off the inflow of warm unstable low-level air.
- Browse Related Terms: CFP, Cold Occlusion, FROPA, Katafront, Occluded Front, Occluded Mesocyclone, OCFNT, PSG, Stationary Front, Warm Occlusion, Warm Sector, WFP, Wrapping Gust Front, WRM, WRMFNT
An optical, ultrasonic, or infrared sensor that turns room lights on when they detect a person's presence and off after the space is vacated.
- Browse Related Terms: Fresnel lens, Light Quality, Light Trapping, Occupancy Sensor, Refraction, Smart Window, Task Lighting, total internal reflection, Visible Light Transmittance