The latest versions (1989c, 1996, 2001, and 2004) of the models and related software can be retrieved from the homepage: http://modelweb.gsfc.nasa.gov/magnetos/data-based/modeling.html
The Tsyganenko model is a semi-empirical best-fit representation for the magnetic field, based on a large number of satellite observations (IMP, HEOS, ISEE, POLAR, Geotail, etc). The model includes the contributions from external magnetospheric sources: ring current, magnetotail current system, magnetopause currents and large-scale system of field-aligned currents. The model author also provides programs GEOPACK-2005 which calculate contribution from internal sources and coordinate transformations.
Additionaly NSSDC has a separate module which calculates contribution from Earth's internal field sources(e.g.:International Geomagnetic Reference Field (IGRF) model) for computing the B and other related parameters, and tracing the field lines.
N. A. Tsyganenko, A. V. Usmanov, Determination of the Magnetospheric Current System Parameters and Development of Experimental Geomagnetic Field Models Based on Data from IMP and HEOS Satellites, Planet. Space Sci. 30, 985-998, 1982.
N. A. Tsyganenko, A. V. Usmanov, V. O. Papitashvili, N. E. Papitashvili, V. A. Popov, Software for Computations of Geomagnetic Field and Related Coordinate Systems, Soviet Geophysical Committee, Special Report, 58 pp., Moscow, 1987.
N. A. Tsyganenko, Global Quantitative Models of the Geomagnetic Field in the Cislunar Magnetosphere for Different Disturbance Levels, Planet. Space Sci. 35, 1347-1358, 1987.
N. A. Tsyganenko, A Magnetospheric Magnetic Field Model with a Warped Tail Current Sheet, Planet. Space Sci. 37, 5-20, 1989.
N. A. Tsyganenko, Modeling the Earth's Magnetospheric Magnetic Field Confined Within a Realistic Magnetopause, J.Geophys.Res., 100, 5599-5612, 1995.
N. A. Tsyganenko and D.P. Stern, Modeling the Global Magnetic Field of the Large-Scale Birkeland Current Systems, J. Geophys.Res., 101, 27187-27198, 1996.
N. A. Tsyganenko, A model of the near magnetosphere with a dawn-dusk asymmetry - 1. Mathematical Structure, J. Geophys.Res., 107, A8, 10.1029/2001JA000219, 2002.
N. A. Tsyganenko, A model of the near magnetosphere with a dawn-dusk asymmetry - 2. Parameterization and fitting to observations, J. Geophys.Res., 107, A7, 10.1029/2001JA000220, 2002.
N. A. Tsyganenko, H. J. Singer, and J. C. Kasper, Storm-time distortion of the inner magnetosphere: How severe can it get? J. Geophys.Res., 108, A5, 10.1029/2002JA009808, 2003.
N. A. Tsyganenko and M. I. Sitnov, Modeling the dynamics of the inner magnetosphere during strong geomagnetic storms, J. Geophys.Res., 110, A3, 10.1029/2004JA010798, 2005.
Please check model homepage for more recent publications.
NASA Official: Dr. Robert McGuire, Head of the Space Physics Data Facility