European Space Agency

Royal Belgian Institute for Aeronomy

ua636 - evaluate a weighted amospheric mass

subroutine  ua636(ktrl, eng, mpos, mb, rmass, ifail)

Parameters:

• ktrl [integer4,in] :: control parameter

• eng [real8,in] :: Energy

• mpos [zgeo,in] :: geographic location

• mb [zvec,in] :: magnetic field vector (unused)

• rmass [real8,out] :: weighted atmospheric mass

• ifail [integer4,out] :: error flag (see Diagnostics)

Description

The subroutine ua636() provides an easy way to average atmospheric density numbers. The argument ktrl is used to control the kind of average (see Table below). When the argument ktrl is different from zero, the weighting includes particle cross sections evaluated by subroutine ua637() or ua638(). The cross sections compiled by Pierrard (see subroutine ua637()) are used when ktrl is set to 1 or 2, while the Hassit cross sections (see subroutine ua636()) are used when ktrl is set to 11 or 12. When the argument ktrl is equal to 0, the density numbers are weighted only by the atomic mass of each component.

ktrl	Weight for the density numbers
0	Atomic mass
1,11	(Atomic mass) x (Proton cross section)
2,12	Proton cross section
1,2	Subroutine ua637() is used
11,12	Subroutine ua638() is used (Hassit)

Note

The units of the output argument rmass are function of the paramater ktrl. The argument eng is then used to indicate the particle energy. The argument mpos indicates where the atmospheric densities have to be evaluated. The subroutine ua636() can be used as argument of subroutine ud320(). Be aware that before any call to the subroutine ua636(), an atmospheric model has to be selected with the help of subroutine ua610().

History

• In version 2.00 and earlier, the sysnopsis of subroutine ua636() does not include the argument mb. This argument has been added from version 2.01 to follow a modification of synopsys in subroutines ud320() and ud321().

Diagnostics

• -63601, atmospheric model incompatible with ktrl parameter

• -63602, illegal ktrl parameter

Common Blocks

• uc150 - atmospheric model

Dependencies

Called by

None

Calls

• ua630 - evaluate the atmospheric densities

• ua634 - compute mass density from number density

• ua635 - evaluate the Debye length

• ua637 - proton cross sections

• ua638 - Hassitt proton cross sections

See also

• ud320 - evaluate a double time integral over a drift shell

• ua610 - select an atmospheric, ionospheric and/or plasmaspheric model

Reported Bugs

None

Examples

None

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UNILIB/tags/v3.02