- 行业: Weather
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The American Meteorological Society promotes the development and dissemination of information and education on the atmospheric and related oceanic and hydrologic sciences and the advancement of their professional applications. Founded in 1919, AMS has a membership of more than 14,000 professionals, ...
The accumulation of a net electrical charge on the surface of aircraft, or the separation of charge into two concentrations of opposite sign on distinct portions of the aircraft surface. Net charges appear as a result of autogenous electrification when aircraft fly through clouds of ice crystals or dust. Charge separation occurs by induction when aircraft fly through regions of strong atmospheric electric field, as in thunderstorms. Charging may also occur by the engine exhaust carrying away a net charge leaving the aircraft charged. Development of large local charges on aircraft parts may lead to appearance of corona discharge or St. Elmo's fire and is almost always accompanied by poor radio communication due to so-called precipitation static.
Industry:Weather
1. After U. S. Weather observing practice, the ceiling classification applied when the reported ceiling value has been determined by a pilot while in flight within one and one-half nautical miles of any runway of the airport. Aircraft ceilings may refer to vertical visibility or obscuring phenomena aloft as well as to clouds, and are designated A in aviation weather observations. 2. The maximum altitude at which any given aircraft can be operated safely.
Industry:Weather
Solid particles suspended in the air. Larger particles (>100 μm approximately) have terminal velocities greater than about 0. 5 m s−1 and fall out quickly. These include hail, snow, graupel, insect debris, room dust, soot aggregates, coarse sand, gravel, and sea spray. Medium-size particles (1 to 100 μm approximately) have sedimentation velocities greater than 0. 2 m h−1 and settle out slowly. These include fine ice crystals, pollen, hair, large bacteria, windblown dust, fly ash, coal dust, silt, fine sand, and small dust. Small particles (<1 μm, approximately) fall so slowly that they can take days to years to settle out of a quiescent atmosphere. For a turbulent atmosphere they may never fall out; however, they can be washed out by rain in a process called rainout or washout, leading to wet deposition onto the earth's surface. Examples of these particles include viruses, small bacteria, metallurgical fumes, soot, oil smoke, tobacco smoke, clay, and fumes. Oil and tobacco smoke are sticky, and are removed from the atmosphere when they happen to touch and stick to an object such as plant or house furnishings, in a process called dry deposition. See criteria pollutants, precipitation.
Industry:Weather
The fractional amount of carbon dioxide, CO2, that remains in the gas phase relative to a given increase in the total amount of CO2 (atmosphere and ocean combined). The relatively high solubility of CO2 in water causes it to partition more favorably in the oceans, and so any potential atmospheric increase is buffered.
Industry:Weather
A device incorporated in some types of mercury barometer to prevent air or other gaseous impurities from entering into the vacuum space.
Industry:Weather
An expendable instrument that is dropped from an aircraft and used to measure the profile of temperature in the water column. The probe consists of a thermistor in a weighted, streamlined case. It falls freely at a fixed, known rate so that the elapsed time can be converted to depth. It is connected by a thin, freely unwinding wire to a small buoy with a radio transmitter through which the data are transmitted to the aircraft, which continues its flight.
Industry:Weather
Hazardous air pollutants that are known or suspected to cause cancer or other serious health effects (such as birth or developmental defects). The U. S. Clean Air Act Amendments of 1990 require emission reductions for 188 hazardous air pollutants from industrial factories and other sources. As of 1996, the U. S. Environmental Protection Agency has issued standards for 47 source categories, such as chemical plants, oil refineries, aerospace manufacturers, and steel mills, as well as dry cleaners, commercial sterilizers, secondary lead smelters, and chromium electroplating processors. Compare designated pollutant, criteria pollutants; see downwash.
Industry:Weather
The temperature indicated by a thermometer exposed to the air in a place sheltered from direct solar radiation.
Industry:Weather
Pertaining to summer. The corresponding adjectives for autumn, winter, and spring are autumnal, hibernal, and vernal.
Industry:Weather
Pertaining to summer. The corresponding adjectives for autumn, winter, and spring are autumnal, hibernal, and vernal.
Industry:Weather
