The Semi-Empirical Low-Latitude Ionospheric Model (SLIM) is based on a theoretical simulation of the low latitude ionosphere. Electron density profiles (180 km to 1800 km) are determined for different latitudes (every 4 degrees between 24 N and 24 S dip latitude) and local times (every hour) by solving the continuity equation for O+ ions. The profiles are normalized to the F2-peak density and are then represented by Modified Chapman function using six coefficients per individual profiles. Calculations are performed for the equinox, June solstice, and December solstice, and for solar cycle minimum and maximum. In total the SLIM model consists of 3 _ 2 _13 _ 24 = 1,872 profiles and 1,872 _ 6 = 11,232 coefficients. Input parameters used in the theoretical calculation include the MSIS model neutral temperatures and densities, the IRI model temperature ratios and the diurnal ion drift patterns observed by the Jicamarca incoherent scatter radar for the different seasons (see also the FAIM Model).
Availability: The profile tables and coefficients are available from authors.
D. N. Anderson, M. Mendillo, and B. Herniter, A Semi-Empirical, Low-Latitude Ionospheric Model, Air Force Geophysics Laboratory, Report AFGL-TR-85-0254, Hanscom AFB, Massachusetts, 1985.
D. N. Anderson, M. Mendillo, and B. Herniter, A Semi-Empirical Low-Latitude Ionospheric Model, Radio Sci. 22, 292, 1987.
NASA Official: Dr. Robert McGuire, Head of the Space Physics Data Facility