European Space Agency

European Space Agency

Royal Belgian Institute for Aeronomy

Royal Belgian Institute for Aeronomy

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ud317 - trace a magnetic drift shell

subroutine  ud317(mlab0, falt, ktyplus, altmin, ifail)
Parameters:

  • mlab0 [zlbl,in] :: Magnetic parameter of the drift shell, i.e. the magnetic field intensity at mirror point Bm and the integral invariant I

  • falt [real8,in] :: Boundary condition on the altitude

  • ktyplus [integer4,in] :: Controlling parameter

  • altmin [real8,out] :: Altitude of the lowest mirror point

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

Description

The subroutine ud317() traces a magnetic drift shell and has the same functionality as subroutine ud310(). The drift shell is defined as a set of magnetic field line segments where all the segments are characterized by the same integral invariant I and the same mirror-point magnetic field intensity. Both values of I and Bm are fixed by the argument mlab0. When the value of I is not validated, the subroutine ul242() is used to compute it from the value of the shell parameter L. The number of field line segments to be traced by the subroutine can not be defined by the user: the number fluctuates between 96 and 108.

The option ktyplus=3 can be used when the only information sought is related to the mirror, equatorial or foot points. It cannot be used if all the points along the drift shell are needed, e.g. to evaluate drift shell averaged atmospheric density.

History

  • The subroutines ud317() and uf417() do not exist in version 1.13 and earlier.

  • From version 2.00 to version 2.01, the number of generated field lines have been increased, and the diagnostics associated to negative values of argument ifail have been changed.

  • In version 2.01 and 2.02, only the error code -31702 is generated instead of both -31701 and -31702.

Diagnostics

  • -31701, the magnetic drift shell has been successfully traced, but the subroutine encountered some problems to determine the foot point locations (see -41704 and -41706)

  • -31702, value of Bm not validated in argument mlab0

Common Blocks

Dependencies

Called by

None

Calls

See also

Reported Bugs

None

Examples

UNILIB/tags/v3.02