# atmoscira

Use COSPAR International Reference Atmosphere 1986 model

## Description

example

[T,pressureOrAltitude,zonalWind] = atmoscira(latitude,ctype,coord) implements the mathematical representation of the Committee on Space Research (COSPAR) International Reference Atmosphere (CIRA) 1986 model. The CIRA 1986 model provides a mean climatology using a latitude, latitude, and a representation of coordinate type, ctype. The mean climatology consists of temperature T, zonal wind zonalWind, and pressure or geopotential height pressureOrAltitude. The provision encompasses nearly pole-to-pole coverage (80 degrees S to 80 degrees N) for 0 km to 120 km. This provision also encompasses the troposphere, middle atmosphere, and lower thermosphere. Use this mathematical representation as a function of pressure or geopotential height.

This function uses a corrected version of the CIRA data files provided by J. Barnett in July 1990 in ASCII format.

[T,pressureOrAltitude,zonalWind] = atmoscira(latitude,ctype,coord,mtype) uses a mean value type, mtype, to implement these values.

[T,pressureOrAltitude,zonalWind] = atmoscira(latitude,ctype,coord,mtype,month) uses a monthly mean value type, month, to implement these values.

[T,pressureOrAltitude,zonalWind] = atmoscira(latitude,ctype,coord,month) uses a mean value type, mtype, and a monthly mean value type, month, to implement these values.

[T,pressureOrAltitude,zonalWind] = atmoscira(___,action) uses the argument action to determine action reporting.

## Examples

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Using the CIRA 1986 model at 45 degrees latitude and 101,300 pascals for January with out-of-range actions generating warnings, calculate the mean monthly values. Calculate values for temperature (T), geopotential height (alt), and zonal wind (zwind).

[T,alt,zwind] = atmoscira(45,'Pressure',101300)
T =
280.6000
alt =
-18
zwind =
3.3000

Using the CIRA 1986 model at 45 degrees latitude and 20,000 m for October, calculate the mean monthly values. Calculate values for temperature (T), pressure (pres), and zonal wind (zwind).

c

[T,pres,zwind] = atmoscira(45,'GPHeight',20000,'Monthly',10)
T =
215.8500
pres =
5.5227e+03
zwind =
9.5000

For September, use the CIRA 1986 model at 45 degrees latitude and –30 degrees latitude. Also use the model at 2000 pascals and 101,300 pascals. Calculate mean monthly values for temperature (T), geopotential height (alt), and zonal wind (zwind).

[T,alt,zwind] = atmoscira([45 -30],'Pressure',[2000 101300],9)
T =
223.5395  290.9000
alt =
1.0e+04 *
2.6692    0.0058
zwind =
0.6300   -1.1000

Using the CIRA 1986 model at 45 degrees latitude and 2000 pascals, calculate annual values. Calculate values for temperature (T), geopotential height (alt), and zonal wind (zwind).

[T,alt,zwind] = atmoscira(45,'Pressure',2000,'Annual')
T =
221.9596    5.0998    6.5300    1.9499    1.3000    1.0499    1.3000
alt =
1.0e+04 *
2.6465    0.0417    0.0007    0.0087    0.0001    0.0015    0.0002
zwind =
4.6099   14.7496    0.6000    1.6499    4.6000    0.5300    1.4000

Use the CIRA 1986 model at 45 and –30 degrees latitude and 20,000 m for October with out-of-range actions generating errors. Calculate values for temperature (T), pressure (pres), and zonal wind (zwind).

[T,pres,zwind] = atmoscira([45 -30],'GPHeight',20000,10,'Error')
T =
215.8500  213.9000
pres =
1.0e+03 *
5.5227    5.6550
zwind =
9.5000    4.3000

## Input Arguments

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Geodetic latitudes, specified as an array, in degrees, where north latitude is positive and south latitude is negative.

Data Types: double

Representation of coordinate type, specified as of these values.

Coordinate TypeDescription
'Pressure'

Pressure in pascals

'GPHeight'

Geopotential height in meters

#### Dependencies

• When ctype is set to 'Pressure', pressureOrAltitude returns the altitude.

• When ctype is set to 'GPHeight', pressureOrAltitude returns the geopotential height.

Data Types: char | string

Pressures or geopotential heights, specified as an array depending on the value of ctype:

Coordinate TypeDescription
'Pressure'

Pressure in pascals

'GPHeight'

Geopotential height in meters

#### Dependencies

• When ctype is set to 'Pressure', the function interprets coord as an array of pressures.

• When ctype is set to 'GPHeight', the function interprets coord as an array of geopotential heights.

Data Types: double

Mean value type of data type string, specified as one of these values.

Mean Value TypeDescription

'Monthly' (default)

Monthly values.

'Annual'

Annual values. Valid when ctype has a value of 'Pressure'.

#### Dependencies

'Annual' is available only when ctype is set to 'Pressure'.

Data Types: char | string

Month in which model takes mean values, specified as one of these values.

ValueMonth

1

January

2

February

3

March

4

April

5

May

6

June

7

July

8

August

9

September

10

October

11

November

12

December

Data Types: double

Function behavior when inputs are out of range, specified as one of these values.

ValueDescription
'None'No action.
'Warning'Warning in the MATLAB® Command Window and model simulation continues.
'Error'MATLAB returns an exception and model simulation stops.

Data Types: char | string

## Output Arguments

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Temperatures, returned as an array depending on the value of mtype.

mtype ValueDescription

'Monthly'

Array of m temperatures, in kelvin

'Annual'

Array of m-by-7 values:

• Annual mean temperature in kelvin

• Annual temperature cycle amplitude in kelvin

• Annual temperature cycle phase in month of maximum

• Semiannual temperature cycle amplitude in kelvin

• Semiannual temperature cycle phase in month of maximum

• Terannual temperature cycle amplitude in kelvin

• Terannual temperature cycle phase in month of maximum

#### Dependencies

'Annual' is available only when ctype is set to 'Pressure'.

Geopotential heights or pressures, returned as an array, depending on the value of ctype.

If mtype is 'Annual', pressureOrAltitude is an array of m-by-7 values for geopotential heights. The function defines this array only for the northern hemisphere (latitude is greater than 0).

• Annual mean geopotential heights in meters

• Annual geopotential heights cycle amplitude in meters

• Annual geopotential heights cycle phase in month of maximum

• Semiannual geopotential heights cycle amplitude in meters

• Semiannual geopotential heights cycle phase in month of maximum

• Terannual geopotential heights cycle amplitude in meters

• Terannual geopotential heights cycle phase in month of maximum

#### Dependencies

• When ctype is set to 'Pressure', pressureOrAltitude returns the altitude.

• When ctype is set to 'GPHeight', pressureOrAltitude returns the geopotential height.

Zonal winds, returned as an array depending on the value of mtype:

mtype ValueDescription

'Monthly'

Array in meters per second.

'Annual'

Array of m-by-7 values:

• Annual mean zonal winds in meters per second

• Annual zonal winds cycle amplitude in meters per second

• Annual zonal winds cycle phase in month of maximum

• Semiannual zonal winds cycle amplitude in meters per second

• Semiannual zonal winds cycle phase in month of maximum

• Terannual zonal winds cycle amplitude in meters per second

• Terannual zonal winds cycle phase in month of maximum

## Limitations

• This function has the limitations of the CIRA 1986 model and limits the values for the CIRA 1986 model.

• The CIRA 1986 model that atmoscira implements limits values to latitudes of 80 degrees S to 80 degrees N on Earth and geopotential heights of 0 to 120 kilometers. atmoscira clips output beyond these ranges.

The CIRA 1986 model data also has missing data points.

• In each monthly mean data set, the model omits values at 80 degrees S for 101,300 pascals or 0 meters because these levels are within the Antarctic land mass.

• In the annual mean data set for latitudes 70, 75, and 80 degrees S, the model also omits these values:

• 101,300 and 78,895 pascal

• 0 and 2,500 meters

As a result of the missing data points, input for pressures above 61,441 pascal or geopotential heights below 5000 meters at these latitudes generate NaN output.

For zonal mean pressure in constant altitude coordinates, pressure data is not available below 20 km. This value is the bottom level of the CIRA climatology.

When atmoscira detects an out-of-range input, the function uses the action argument to determine the function behavior.

## References

[1] Fleming, E. L., S. Chandra, M. R. Shoeberl, and J. J. Barnett. Monthly Mean Global Climatology of Temperature, Wind, Geopotential Height and Pressure for 0-120 km. NASA TM100697, February 1988.

## Version History

Introduced in R2007b

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