Implement mathematical representation of 1986 CIRA atmosphere
Environment/Atmosphere
The CIRA86 Atmosphere Model block implements the mathematical representation of the 1986 Committee on Space Research (COSPAR) International Reference Atmosphere (CIRA). The block provides values for absolute temperature, pressure, density, and speed of sound for the input geopotential altitude.
The CIRA86 Atmosphere Model block icon displays the input and output units selected from the Units list.
Specifies the input and output units:
Units  Height  Temperature  Speed of Sound  Air Pressure  Air Density 

 Meters  Kelvin  Meters per second  Pascal  Kilograms per cubic meter 
 Feet  Degrees Rankine  Feet per second  Poundforce per square inch  Slug per cubic foot 
 Feet  Degrees Rankine  Knots  Poundforce per square inch  Slug per cubic foot 
Specify the representation of the coordinate type. The default
is GPHeight
.
Pressure
Indicates pressure in pascal.
GPHeight
Indicates geopotential height in meters.
Specify mean value types. The default is Monthly
.
Monthly
Indicates monthly values. If you select Monthly
,
you must also set the Month parameter.
Annual
Indicates annual values. Valid when Coordinate type has
a value of Pressure
.
Indicates the month in which the mean values are taken. From
the list, select the desired month. This parameter applies only when Mean
value type has a value of Monthly
.
Specify if outofrange input invokes a warning, error, or no action.
Input  Dimension Type  Description 

First  Array  Contains the latitude in degrees (limited to +/80 degrees). 
Second  Array  Contains an

Output  Dimension Type  Description 

First  Array  Contains mean temperature in selected units. 
Second  Array  Contains an

Third  Array  Contains mean zonal winds in selected units. 
This function uses a corrected version of the CIRA data files provided by J. Barnett in July 1990 in ASCII format.
This function has the limitations of the CIRA 1986 model. The values for the CIRA 1986 model are limited to the regions of 80 degrees S to 80 degrees N on the Earth and geopotential heights of 0 to 120 kilometers. In each monthly mean data set, values at 80 degrees S for 101,300 pascal or 0 meters were omitted because these levels are within the Antarctic land mass. For zonal mean pressure in constant altitude coordinates, pressure data is not available below 20 kilometers. Therefore, this is the bottom level of the CIRA climatology.
Fleming, E. L., Chandra, S., Shoeberl, M. R., Barnett, J. J., Monthly Mean Global Climatology of Temperature, Wind, Geopotential Height and Pressure for 0120 km, NASA TM100697, February 1988