Atmospheric Water Vapor, Precipitable Water Vapor, or Humidity is a measure of the water vapor content of
the air. It is one of the most important greenhouse gases of the
atmosphere. More than fifty percent of all of the atmospheric water vapor is found below an
altitude of 2 km, and only a minute fraction of the total occurs above the tropopause. Water vapor is
a major vehicle for the transport of energy (latent heat) and acts as a regulator of
planetary temperatures through absorption and emission of radiation, most significantly in
the thermal infrared (the greenhouse effect).
There are a number of atmospheric variables
that are used to express the amount of water vapor present in the atmosphere. Some of them are briefly described below.
Absolute Humidity: the mass of water vapor per unit volume of air containing the water vapor (units g/m
3
)
Specific Humidity: It is the ratio of the weight of water vapor in
a specified volume to weight of dry air in the same volume (dimensionless).
Absolute Humidity:
The mass of water vapor per unit volume of air containing the water vapor (units g/m
3
)
Specific Humidity:
The ratio of the weight of water vapor in
a specified volume to the weight of dry air in the same volume (dimensionless).
Relative Humidity:
The ratio of actual measured water vapor amount to the saturation vapor
pressure (the maximum possible water vapor amount after which it condenses as dew) at a specific
temperature.
Precipitable Water Vapor:
The amount of water (depth of vertical column of unit-cross-sectional area) which would be obtained if all the water vapor in a specified
column of the atmosphere were condensed to liquid.
Dewpoint Temperature:
The temperature to which a given parcel of air must be cooled (at constant pressure) for saturation to occur. It is also used as a measure of humidity.
Daily time ordered collection of data records at 65.536 second intervals, gridded to the UARS pressure array. Each measured parameter is stored in a separate data file.
Daily time ordered collection of data records at 65.536 second intervals, gridded to the UARS pressure array. Each measured parameter is stored in a separate data file.
TMI Hydrometeor (cloud liquid water, prec. water, cloud ice, prec. ice) profiles in 14 layers at 5 km horizontal resolution, along with latent heat and surface rain, over a 760 km swath
Available Services:
HIRDLS V003 Level-2 daily data product contains vertical profiles of Ozone (O3), Nitric Acid (HNO3) and Temperature, as well as Cloud Top Pressure at spatial resolution of about 100 km along orbit track. This product (HIRDLS2.003) is based on the HIRDLS v2.04.09 algorithm.
Available Services:
Rain rate, cloud liquid water, rain water, cloud ice, grauples at 14 levels for a latitude band from 40 degree N to 40 degree S, from PR and TMI
Available Services:
Daily latitude and time ordered collection of data records at 4 degree latitude intervals, gridded to the UARS pressure array. Each measured parameter is stored in a separate data file.
Daily time ordered collection of data records at 65.536 second intervals, gridded to the UARS pressure array. Each measured parameter is stored in a separate data file.
0.5 x 0.5 degree gridded monthly product comprised of mean 2A12 data and calculated vertical hydrometeor profiles as well as mean surface rainfall
Available Services:
HIRDLS V004 Level-2 daily data product contains vertical profiles of Ozone (O3), Nitric Acid (HNO3), CFC-11, CFC-12, Aerosol Extinction (12.1 micron) and Temperature, as well as Cloud Top Pressure at spatial resolution of about 100 km along orbit track. This product (HIRDLS2.004) is based on the HIRDLS v2.04.19 algorithm.
Available Services:
Daily latitude and time ordered collection of data records at 4 degree latitude intervals, gridded to the UARS pressure array. Each measured parameter is stored in a separate data file.
Daily latitude and time ordered collection of data records at 4 degree latitude intervals, gridded to the UARS pressure array. Each measured parameter is stored in a separate data file.
Daily time ordered collection of data records at 65.536 second intervals, gridded to the UARS pressure array. Each measured parameter is stored in a separate data file.
Atmos Composition
