Open-file Report no.402

GSJ Open-file Report, no. 402

Calculation of the International Geomagnetic Reference Field (3)

Tadashi Nakatsuka (Institute of Geoscience, GSJ/AIST)

Abstract

International Geomagnetic Reference Field (IGRF) is a mathematical model of the geomagnetic field originating from the Earth's interior, and it is adopted at the meeting of the International Association of Geomagnetism and Aeronomy (IAGA).

This Open-file Report is a revised version for the former report with same title (GSJ Open-file Report, no. 184, 1992). The description on the adoption of new IGRF models since 1995 (until 2003) is added and the FORTRN source code is updated to cover the newer model calculation. The C language subprogram is also presented.

The history of the adoption of IGRF models are summarized as follows.

Date Place (Assembly) Adoption Time Span

Oct., 1968 Washington (IAGA Symp.) 1st Generation: IGRF1965 1955-1972

Sept., 1973 Kyoto (IAGA) Apply IGRF1965 until 1975 1955-1975

Sept., 1975 Grenoble (IUGG) 2nd Generation: IGRF1975 1955-1980

Aug., 1981 Edinburgh (IAGA) 3rd Generation: IGRF1980
Notion of DGRF/PGRF: DGRF1965-1975 1965-1985

Aug., 1985 Prague (IAGA) 4th Generation: IGRF1985, DGRF1980
non-definitive models IGRF1945-1960 1945-1990

Aug., 1987 Vancouver (IUGG) 5th Generation: definitive models DGRF1945-1960 1945-1990

Aug., 1991 Vienna (IUGG) 6th Generation: IGRF1990, DGRF1985 1945-1995

Sept., 1995 Boulder (IUGG) 7th Generation: IGRF1995, DGRF1990
non-definitive models IGRF1900-IGRF1940 1900-2000

July, 1999 Birmingham (IUGG) Set up Task Force do.

Dec., 1999 (Task Force) 8th Generation: IGRF2000 1900-2005

Aug., 2001 Hanoi (IAGA/IASPEI) DGRF1995 and DGRF2000 are to be discussed at Sapporo in 2003 do.

July, 2003 Sapporo (IUGG) 9th Generation: DGRF1995, DGRF2000
Notation by generation (e.g., IGRF-8 1997.5) 1900-2005

Date	Place (Assembly)	Adoption	Time Span
Oct., 1968	Washington (IAGA Symp.)	1st Generation: IGRF1965	1955-1972
Sept., 1973	Kyoto (IAGA)	Apply IGRF1965 until 1975	1955-1975
Sept., 1975	Grenoble (IUGG)	2nd Generation: IGRF1975	1955-1980
Aug., 1981	Edinburgh (IAGA)	3rd Generation: IGRF1980 Notion of DGRF/PGRF: DGRF1965-1975	1965-1985
Aug., 1985	Prague (IAGA)	4th Generation: IGRF1985, DGRF1980 non-definitive models IGRF1945-1960	1945-1990
Aug., 1987	Vancouver (IUGG)	5th Generation: definitive models DGRF1945-1960	1945-1990
Aug., 1991	Vienna (IUGG)	6th Generation: IGRF1990, DGRF1985	1945-1995
Sept., 1995	Boulder (IUGG)	7th Generation: IGRF1995, DGRF1990 non-definitive models IGRF1900-IGRF1940	1900-2000
July, 1999	Birmingham (IUGG)	Set up Task Force	do.
Dec., 1999	(Task Force)	8th Generation: IGRF2000	1900-2005
Aug., 2001	Hanoi (IAGA/IASPEI)	DGRF1995 and DGRF2000 are to be discussed at Sapporo in 2003	do.
July, 2003	Sapporo (IUGG)	9th Generation: DGRF1995, DGRF2000 Notation by generation (e.g., IGRF-8 1997.5)	1900-2005

The text of this report in Japanese consists of the following sections.
     1. Introduction
     2. Outline of IGRF, its history of adoption
     3. Basic formulation for IGRF
     4. Algorithm of calculation
     5. Function of subprograms presented
     6. Brief explanation for the subprograms
     7. How to use (example)
     References
     Appendix-1. Source list of FORTRAN subprograms
     Appendix-2. Source list of C language subprogram
     Appendix-3. Contents of attached diskette

Following files are included in this Open-file Report.

Filename Format Content

igrf.3a.doc MS Word Document (in Japanese) Body text of this Open-file Report (Former half, pp. 0-15)

igrf.3b.doc MS Word Document (in Japanese) Appendices of this Open-file Report (Latter half, pp. 16-39)

igrf.f Simple text Source code of FORTRAN subprograms

igrf.c Simple text Source code of C language subprograms

igrf01.coef Simple text Gauss coefficients data for the 1st generation IGRF

igrf02.coef Simple text Gauss coefficients data for the 2nd generation IGRF

igrf03.coef Simple text Gauss coefficients data for the 3rd generation IGRF

igrf04.coef Simple text Gauss coefficients data for the 4th generation IGRF

igrf05.coef Simple text Gauss coefficients data for the 5th generation IGRF

igrf06.coef Simple text Gauss coefficients data for the 6th generation IGRF

igrf07.coef Simple text Gauss coefficients data for the 7th generation IGRF

igrf08.coef Simple text Gauss coefficients data for the 8th generation IGRF

igrf09.coef Simple text Gauss coefficients data for the 9th generation IGRF

index.html HTML Document (in English) English abstract of this Open-file Report (This document)

indexJ.html HTML Document (in Japanese) Japanese abstract of this Open-file Report

Filename	Format	Content
igrf.3a.doc	MS Word Document (in Japanese)	Body text of this Open-file Report (Former half, pp. 0-15)
igrf.3b.doc	MS Word Document (in Japanese)	Appendices of this Open-file Report (Latter half, pp. 16-39)
igrf.f	Simple text	Source code of FORTRAN subprograms
igrf.c	Simple text	Source code of C language subprograms
igrf01.coef	Simple text	Gauss coefficients data for the 1st generation IGRF
igrf02.coef	Simple text	Gauss coefficients data for the 2nd generation IGRF
igrf03.coef	Simple text	Gauss coefficients data for the 3rd generation IGRF
igrf04.coef	Simple text	Gauss coefficients data for the 4th generation IGRF
igrf05.coef	Simple text	Gauss coefficients data for the 5th generation IGRF
igrf06.coef	Simple text	Gauss coefficients data for the 6th generation IGRF
igrf07.coef	Simple text	Gauss coefficients data for the 7th generation IGRF
igrf08.coef	Simple text	Gauss coefficients data for the 8th generation IGRF
igrf09.coef	Simple text	Gauss coefficients data for the 9th generation IGRF
index.html	HTML Document (in English)	English abstract of this Open-file Report (This document)
indexJ.html	HTML Document (in Japanese)	Japanese abstract of this Open-file Report

References (in chronological order)

Chapman, S. and J. Bartels (1940) Spherical harmonic analysis in geophysics. Geomagnetism, vol.2, 606-638. Oxford Univ. Press, New York.
International Astronomical Union (IAU) (1966) Proceedings of the Twelfth General Assembly, Hanburg, Germany. Trans. IAU, 12B, 594-595.
IAGA Commision 2 Working Group No.4, Analysis of the Geomagnetic Field (1969) The International Geomagnetic Reference Field 1965.0, J. Geomag. Geoelectr., 21, 569-571; J. Geophys. Res., 74, 4407-4408.
International Association of Geomagnetism and Aeronomy (IAGA) (1973) Transactions of the Second General Scientific Assembly, Kyoto, Japan. IAGA Bull., no.35, 147, Resolution 18.
IAGA Division I Study Group, Geomagnetic Reference Fields (1975) International Geomagnetic Reference Field 1975, J. Geomag. Geoelectr., 27, 437-439; Eos Trans. AGU, 57, 120-121 (1976); J. Geophys. Res., 81, 5163-5164 (1976); Geophys. J. Roy. Astron. Soc., 44, 733-734 (1976).
Peddie, N. W. (1981) International Geomagnetic Reference Field 1980: a report by IAGA Division I Working Group 1, J. Geomag. Geoelectr., 33, 607-611; Geophys. J. Roy. Astron. Soc., 68, 265-268 (1982); Geophysics, 47, 841-842 (1982).
IAGA Division 1 Working Group 1 (1981) International Geomagnetic Reference Fields: DGRF 1965, DGRF 1970, DGRF 1975, and IGRF 1980, Eos Trans. AGU, 62, 1169.
Peddie, N. W. (1982) International Geomagnetic Reference Field: the third generation, J. Geomag. Geoelectr., 34, 309-326.
Peddie, N. W. (1983) International Geomagnetic Reference Field - its evolution and the difference in total field intensity between new and old models for 1965-1980, Geophisics, 48, 1691-1696.
IAGA Division I Working Group 1 (1985) International Geomagnetic Reference Field Revision 1985, J. Geomag. Geoelectr., 37, 1157-1163; IAGA News, no.24, 60-64; Pure Appl. Geophys., 123, 641-645; Eos Trans. AGU, 67, 523-524 (1986); Geophys. J. Roy. Astron. Soc., 85, 217-220 (1986); Geophysics, 51, 1020-1023 (1986).
Nakatsuka, T. (1986) Calculation of the International Geomagnetic Reference Field. GSJ Open-file Report, no.27, 25p., Geol. Surv. Japan (in Japanese).
Barraclough, D. R. (1987) International Geomagnetic Reference Field: the fourth generation, Phys. Earth Planet. Inter., 48, 279-292.
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Langel, R. A. (1992) International Geomagnetic Reference Field: the sixth generation, J. Geomag. Geoelectr., 44, 679-707.
Nakatsuka, T. (1992) Calculation of the International Geomagnetic Reference Field (2). GSJ Open-file Report, no.184, 27p. + 1 diskette, Geol. Surv. Japan (in Japanese).
IAGA Division V Working Group 8 (1995) International Geomagnetic Reference Field, 1995 Revision, J. Geomag. Geoelectr., 47, 1257-1261; Geophys. J. Int., 125, 318-321 (1996); Phys. Earth Planet. Inter., 97, 23-26 (1996); Pure Appl. Geophys., 147, 195-202 (1996).
Barton, C. E. (1997) International Geomagnetic Reference Field: the seventh generation, J. Geomag. Geoelectr., 49, 123-148.
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Mandea, M. and S. Macmillan (2000) International Geomagnetic Reference Field - the eighth generation, Earth Planets Space, 52, 1119-1124.
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Macmillan, S. and S. McLean (2003) IAGA Division V-MOD Geomagnetic Field Modeling: Minutes Hanoi 2001. http://www.ngdc.noaa.gov/IAGA/vmod/min2001.html, 23 September, 2003.
IAGA Division V Working Group 8 (2003) The 9th Generation International Geomagnetic Reference Field, Earth Planets Space, 55(8), i-ii.