Definitions for "Air Mass"
Related Terms:
Stable air, Advection fog, Unstable air, Overrunning, Warm front, Air parcel, Arctic air, Lcl , Cold front, Front, Advection, Maritime air mass, Temperature inversion, Upslope fog, Tropical air, Continental air mass, Convection current, Low pressure, Stack effect, Inversion, Thermal inversion, Radiation fog, Entrainment, Cap , Virtual temperature, Contrail, Wind, Equivalent potential temperature, Sounding, Plume, Convection currents, Downdraft, Polar front, Atmospheric, Potential temperature, Aërostat, Orographic lifting, Clear-air turbulence, Thermal, Convection, Updraft, Frost point, Standard air, Hot air balloon, Rocketsonde, Dew point, Dry adiabatic lapse rate, Free air, Frontogenesis
An extensive body of air having the same properties of temperature and moisture in a horizontal plane.
A mass of air which is largely homogeneous in a horizontal direction. Its physical properties are determined by the nature of the surface over which it forms, and may be subsequently modified when the air mass moves over a different type of surface. Air masses are often separated from each other by frontal surfaces, which are discontinuities.
A large scale portion of the earth's atmosphere whose properties (principally temperature and moisture) are approximately uniform. A system commonly used to classify air according to their source regions. In this system, air masses are identified according to the thermal and moisture properties of their source region. Thermal identifications are tropical (T), polar (P), and less frequently, arctic (A) or antarctic (AA). Moisture characterizations are continental (c), which is relatively dry, and maritime (m), which is relatively moist.
A large expanse of air having similar temperature and humidity at any given height.
A body of air, about 1,500 km across, that has recognizable physical characteristics.
The ratio of the mass of atmosphere in the actual observer-sun path to the mass that would exist if the observer was at sea level, at standard barometric pressure, and the sun was directly overhead. Note--(sometimes called air mass ratio). Air mass varies with the zenith angle of the sun and the local barometric pressure, which changes with altitude. For sun zenith angle, Z, of 62 degrees or less and local atmospheric pressure, P, where Po is standard atmospheric pressure, AM approximately equal sec Z(P/Po). [ASTM E 772] Alternatively, the path length of light through the atmosphere is described in terms of an equivalent relative air mass. AM0 corresponds to the solar spectrum in outer space; at the equator, the average spectrum is AM1, and the reference spectrum for STC was defined to be AM1.5 (average spectrum at 45-degrees latitude).
A large body of air with only small horizontal variations of temperature, pressure, and moisture. Although an air mass has distinct boundaries, it may extend hundreds or even thousands of miles. Air masses are found when the atmosphere is in contact with a uniform land or ocean surface long enough for it to acquire the temperature and moisture of that surface. On the Earth, major air masses originate in polar or subtropical latitudes. We are usually within an air mass. When there is a change in temperature, a different air mass is moving in.
In meteorology, a continguous and widespread body of air that has been stagnant over a surface for a sufficient length of time to have been modifed by the surface. An example would be a maritime air mass that develops with high humidity over an ocean. The formation of air masses is favored in regions of surface high pressure regions due to the ambient light winds allowing the long residence time necessary for modification. Given the prevailing global circulation patterns, warm air mass formation is favored at 30 latitude and cold air mass formation at 90 latitude, with the boundary between these two regions being known as the polar front.
A large volume of air with uniform properties of temperature and moisture.
body of air within which temperature and moisture are uniform
A large volume of air (often covering thousands of square kilometers) with temperature and humidity characteristics that vary little horizontally.
A large body of air with about the same characteristics, such as temperature, pressure, and humidity.
A very large body of atmosphere defined by essentially similar horizontal air temperatures. Moisture conditions are also usually similar throughout the mass.
a large body of air with uniform characteristics horizontally
a body of air that extends over a large area and has nearly uniform temperature and humidity in any horizontal direction
a body or 'mass'of air in which the horizontal gradients or changes in temperature and humidity are relatively slight
a huge volume of air covering thousands of square miles or kilometers that is relatively uniform in temperature and humidity
a large body of air (See Fig
a large body of air, sometimes extending thousands of kilometres, which has relatively uniform characteristics of temperature and moisture
a large body of air that, at any one height, has a relatively steady temperature and moisture content throughout
a large body of air that has similar moisture (density) and temperature characteristics
a large body of air that has similar temperature and moisture properties throughout
a LARGE Body of Air that may extend over a large part of a Continent or Ocean
a large body of air that shares similar levels of temperature, moisture, and atmospheric pressure
a large body of air with relatively uniform temperature and moisture characteristics
a large body of air with similar
a large portion of air that originates over a certain area
a large section of the troposphere with uniform properties of temperature and moisture in the horizontal
a large unit of air and can cover hundreds of thousands of square miles
an expansive area of air with uniform temperature and moisture content
an extensive body of air that has a relatively homogeneous temperature and moisture content over a significant altitude
a uniform body of air that moves unmodified from location to location
a vast pool of air having similar temperature and moisture characteristics over its horizontal extent
a very large body of air that has similar properties
a large body of air with a fairly uniform temperature and moisture throughout. The transition zone between different air masses is called a front. In a cold front, cold air is replacing warm; in a warm front, warm air is replacing the cold.
An extensive body of air in a horizontal plane having fairly uniform properties of temperature and moisture.
A large body of air where the horizontal distribution of temperature, pressure, and moisture is nearly uniform.
a large quantity of air throughout which temperature and moisture content is fairly constant.
A parcel of air that contains uniform properties. Air masses are defined by their origin (Polar, Tropical. Equatorial or Southern) and their qualities (continental or maritime) .
A large body of air characterized by similar physical qualities. (ie. warm air mass, cold air mass, etc.)
A large body of air having uniform temperature and moisture.
A measure of distance that light travels through the earth's atmosphere.
A large body of air with relatively uniform characteristics such as temperature and humidity.
A large volume of air with certain meteorological or polluted characteristics--e.g., a heat inversion or smogginess--while in one location. The characteristics can change as the air mass moves away.
A large body of air that has nearly uniform conditions of temperature and humidity.
A measure of how far light travels through the Earth's atmosphere. One air mass, or AM1, is the thickness of the Earth's atmosphere. Air mass zero (AM0) describes solar irradiance in space, where it is unaffected by the atmosphere.
a body of air that extends hundreds or thousands of kilometers horizontally and is relatively uniform in temperature and moisture content (see continental arctic, continental polar, continental tropical, maritime polar, and maritime tropical air masses); because all thunderstorms are associated with some type of forcing mechanism, synoptic-scale or otherwise, the term is somewhat controversial and should be used with discretion
A large body of air with nearly uniform temperature and moisture content.
A body of air with similar properties of density, heat and moisture content throughout. An air mass will usually cover many thousands of square miles. It is at the interface or boundaries of differing air masses that stormy, unsettled weather occurs.
a large body of air all of similar temperature and humidity.
A wide-spread body of air that is approximately homogeneous in horizontal extent, particularly with reference to vertical temperature and moisture distribution.
A large, horizontal body of air with a uniform distribution of moisture and temperature throughtout.
a large, horizontal parcel of air that has similar temperatures and humidity throughout.
An extensive body of air throughout which the horizontal temperature and moisture characteristics are similar.
An extensive body of the atmosphere whose physical properties, particularly temperature and humidity, exhibit only small and continuous differences in the horizontal. It may extend over an area of several million square kilometers and over a depth of several kilometers.
An extensive body of air with uniform conditions of moisture and temperature in the horizontal.
A large body of air having similar temperature and moisture characteristics.
A body of air covering a relatively wide area and exhibiting horizontally uniform properties.
a very large area of air with the same temperature throughout
is a large body of air which has the same condition of moisture and temperature throughout its horizontal levels
A large body of air with the uniform temperature and humidity of its source region.