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Trapped Radiation ENvironment model Development

UF417

[ Name | Synopsis | Arguments | Description | Diagnostics | Common Blocks | Dependencies | See Also | Reported Bugs | Examples ]

Name

    Subroutine UF417 - search the geographic position of a magnetic field line (new)

Synopsis

      REAL*8        fim, fbm, glon, guess, falt
      INTEGER*4     ifail
      RECORD /zgeo/ mpos   
      
      CALL UF470 (fim, fbm, glon, guess, mpos, falt, ifail)

Arguments

    fim
    Value of the integral invariant I [in]
    fbm
    Magnetic field intensity at the mirror points [in]
    glon
    Equatorial longitude [in]
    guess
    Equatorial radius [in/out]
    mpos
    Equatorial location [out]
    falt
    Boundary condition on the altitude [in]
    ifail
    Error flag (see diagnostics) [out]

Description

    The subroutine UF417 searches iteratively a magnetic field line segment for which the integral invariant I, the magnetic field intensity Bm at the mirror points and the longitude of the point with the lowest magnetic field intensity are fixed. The values of I, Bm and longitude are passed through the arguments fim, fbm and glon, respectively. The functionality of subroutine UF417 is very similar to the one of subroutine UF410 which depends on the shell parameter L instead of I. The subroutine UF417 seems to be better suited for equatorial field line segment (I=0).

    The argument guess can be used to guess the geocentric radius of the point with the lowest magnetic field intensity. As a result, the magnetic field line segment is returned in the common block UC170, the argument guess is set to the current geocentric radius and the argument mpos contains the geographic location of the local magnetic equator. Note that the argument falt can be used such that the subroutine traces the field line till the foot points.

History

    The subroutines UF417 and UD317 do not exist in version 1.13 and earlier.

Diagnostics

    -41701, field line segment not found, probably the value of Bm is less than B0
    -41702, field line segment not found
    -41703, too many iterations
    -41704, field line segment found, but problem with the altitude boundary
    -41705, invalid value of flm or fbm argument
    -41706, field line segment found, but the field line is passing below the altitude boundary

Common Blocks

    UC160, general constants
    UC190, control parameters, set 1
    UC192, control parameters, set 2

Dependencies

Called by

    UD317, trace a magnetic drift shell

Calls

    UF411, search a local magnetic equator
    UF415, rebuild the labels of the field line
    UF420, trace a magnetic field line segment passing through a given position

See also

    None

Reported Bugs

    None

Examples

    None