Royal Belgian Institute for Aeronomy¶

ul242 - inverse the Hilton function¶

subroutine ul242(mlab, ifail)¶

Parameters:

mlab [zlbl,in/out] :: Magnetic parameter of a field line segment.
ifail [integer4,out] :: error flag (see Diagnostics)

Description¶

The subroutine ul242() determines the integral invariant I from the values of McIlwain’s shell parameter L and the magnetic field intensity Bm at the mirror points. The determination is done by evaluating the inverse of Hilton’s function. The inputs and result of the subroutine are passed by argument mlab in a similar way than for subroutine ul240().

Note

The behaviour of subroutine ul242() depends as subroutine ul240() on the argument kmflg of the common block uc190.

History¶

The subroutine ul242() is not included in version 1.13 and earlier.

From version 2.00 to 2.02, the subroutine presents a lack of accuracy at low I values.

Diagnostics¶

-24201, value of Bm not available

-24202, value of L not available

-24203, not able to compute I

-24204, Bm less than the equatorial value of the magnetic field intensity

Common Blocks¶

uc140 - magnetic field

uc160 - general constants

uc190 - control parameters, set 1

Dependencies¶

Called by¶

ud317 - trace a magnetic drift shell

uf410 - search the geographic position of a magnetic field line

Calls¶

None

Reported Bugs¶

In version 2.00 and earlier the subroutine was not accurate for Bm value near to B0, i.e. value of I near zero.

Examples¶