atmo-, atm- +
(Greek: vapor, steam; air, gas; respiration)
2. The general name for an instrument which measures the evaporation rate of water into the atmosphere.
Atmometrics involves the measuring of the evaporation of water from a free water surface; such as, a pan of water set into the ground so the water's surface is even with the ground's surface, or from a porous, water-saturated surface; such as, filter paper placed over a graduated cylinder of water.
The atmosphere consists of four distinct layers, whose boundaries are not precise:
- The troposphere (extending from sea level to about 5-10 miles [10 to 20 km] above the earth.
- The stratosphere (up to about 30 miles [50 km]).
- The mesosphere (up to about 60 miles [96 km]).
- The thermosphere (up to about 300 miles or more [480 km]).
The upper region of the troposphere is often regarded as a separate region known as the exosphere.2. The gas bound gravitationally to a planet or the pressure of the air on the earth at mean sea level; approximately 14.7 pounds per square inch or 760 millimeters high at 0 degrees Celsius under standard gravity: "Through the powerful telescope, the astronomers were able to study the atmosphere of the distant planets."
"Although some details about the atmospheres of other planets and satellites are known, only the earth's atmosphere has been well studied, the science of which is called meteorology."3. The outer layers of a star: "The atmosphere surrounding the star appears to cause the twinkle effect which romantic couples dream about."
4. A supposed outer envelope of effective influences surrounding various bodies: "The atmosphere of the capital city was one of individuals and corporations attempting to influence politicians."
5. Prevailing psychological climate; pervading tone or mood; characteristic mental or moral environment; fascinating or beguiling associations or effects: "The atmosphere in the office appeared to be edgy as if there were major staff changes anticipated but no one knew when that would happen."
6. Applied to the background sounds that evoke a particular mood, impression, setting, etc., in a broadcast program, etc.: "The atmosphere created by the music was dark and mysterious."
7. The air in any particular place; especially, as affected in its condition by heat, cold, purifying or contaminating influences, etc.: "The old wood stove was not well maintained and smoked, creating a smoky atmosphere in the cabin."
8. The predominant tone or mood of a work of art or the pervading quality, effect, or mood; especially, as associated with a particular place: "Henry lived in a dark old house with a depressing atmosphere."
9. A distinctively exotic or romantic quality or effect: "Willy and Gertrude went to an Italian restaurant where there was lots of atmosphere."
2. Dependent on, caused by, or resulting from the collection of gases surrounding the surface of the earth or other celestial bodies: "The moon glimmered through the atmospheric haze caused by the wispy clouds in the sky."
3. Giving or creating a distinctive quality or effect in a location: "The atmospheric music in the background of the restaurant encouraged patrons to relax and to enjoy their meals."
2. The reduction of the energy of microwaves by the presence of moisture in the gases surrounding the earth: "The static in the skies at night in the local area appeared to cause the atmospheric absorption of the microwaves, which were interfering with the radar system."
Scintillation refers to the rapid fluctuations in the amplitude and phase of electromagnetic or acoustic waves that have propagated through a medium containing fluctuations in refractive index, such as the atmosphere.
The most common example of optical scintillation is the "twinkling" of stars observed through the atmosphere because it arises as a result of random angular scattering produced by refractive index fluctuations.
Fluctuations in the amplitude of different frequency components in the spectrum of an object can give rise to apparent changes in its color (chromatic scintillation); an example is the random red and blue twinkling of bright stars near the horizon.
Scintillation statistics have been used to study turbulence in regions ranging from the planetary boundary layer to the ionosphere, as well as interplanetary and interstellar space and it is important for astronomical imaging, optical and radio communications, laser and acoustical propagation, active and passive remote sensing, and the performance of the Global Positioning System.
2. The thin layer of air adjacent to the earth's surface, usually considered to be less than 300 feet (91 meters) high.
3. The thin layer of air adjacent to the earth's surface, extending up to the so-called anemometer level (the base of the Ekman layer [thin top layer of the sea]); within this layer the wind distribution is determined largely by the vertical temperature gradient and the nature and contours of the underlying surface, and shearing stresses are approximately constant.