[ Name | Synopsis | Arguments | Description | Diagnostics | Common Blocks | Dependencies | See Also | Reported Bugs | Examples ]
Subroutine UM510 - select a geomagnetic field model
INTEGER*4 kint, kunit, ifail REAL*8 year CHARACTER*32 lbint CALL UM510 (kint, year, lbint, kunit, ifail)
- Index of the geomagnetic field model (-2, -1, 0, 1, 2, 3 or 4) [in]
- Epoch of the geomagnetic field calculation expressed in year [in]
- Label of the geomagnetic field model [out]
- File unit for the summary table (see note of subroutine UT990) [in]
- Error flag (see diagnostics) [out]
The subroutine UM510 may be used to initialize the geomagnetic
field description inside the common block UC140.
kintargument allows to choose between four models as listed below.
||Geomagnetic field model||Remarks|
|1||Jensen & Cain (1962)||fixed to epoch 1960|
|-1||Jensen & Cain (1962)||fixed to epoch 1960 and corrected for the SAA westward drift|
|-2||GSFC 12/66||fixed to epoch 1970 and corrected for the SAA westward drift|
|3||Dipole magnetic field||-|
|4||DGRF/IGRF 45-95||use the Kluge algorithm to evaluate the geomagnetic field|
yearargument specifies the epoch used to evaluate the geomagnetic field model. The Jensen & Cain model does not depend on time and has its epoch fixed to 1960. When
kunitis greater than zero, a summary table is written by the subroutine. As result, the
lbintargument contains a string with the label of the selected internal magnetic field model.
The Jensen & Cain model has been used to produce the NASA trapped
radiation belt models AP-8 MIN, AE-8 MIN and AE-8 MAX. The
GSFC 12/66 model, updated to 1970, has been used to generate AP-8
MAX model. Since these NASA models were built more than twenty years
ago, the location of the South Atlantic Anomaly (SAA) has shifted
considerably to the West compared to its location predicted by the two
old magnetic field models, due to the secular variation of
the geomagnetic field distribution. When the
is set to -1 or -2, the effect of this drift will be compensated by
applying an eastward rotation to the geographic coordinates before
the evaluation of the internal magnetic field.
- Cain, J.C., Hendricks, S.J., Langel, R.A. and Hudson, W.V., A proposed model for the international geomagnetic reference field-1965, J.Geomag.Geoelectr. 19 (1967) 335-355
- Heynderickx, D., Comparison between methods to compensate for the secular motion of the south atlantic anomaly, Aeronomica Acta 385 (1994)
- Jensen, D.C. and Cain, J.C., An interim geomagnetic field, JGR 67 (1962) 3568
In version 2.02 and earlier the string returned by argument
lbintis not correctly copied in the argument
mint.labelof common block UC140.
-51001, invalid geomagnetic field model index
-51002, geomagnetic field uncorrectly loaded
-51003, error on output device
set the Jensen & Cain 1960 model coefficients
UM512, set the GSFC 12/66 model coefficients
UM513, set the DGRF/IGRF model coefficients
UM517, transform from Schmidt to Kluge normalisation
- Problems have been discovered in subroutine UM510 when the
kintis set to 4 (evaluation of DGRF/IGRF by the Kluge algorithm).
#1, evaluation of the magnetic field vector
#2, evaluation of the (B, L) coordinates
#3, evaluation of the third invariant
#4, search the point with the lowest altitude on a magnetic drift shell
#5, namelist to initialize UNILIB
#7, iso-contour of the shell parameter
G.06 How to start using the UNILIB library ?
T.03 How to customize the magnetic field model used by the library ?
T.04 Why are Roederer's L* and McIlwain's L parameters different ?