Extension of the MSIS Thermosphere Model into the middle and lower atmosphere

TLDR

The MSIS‑86 model was revised and extended into the mesosphere and lower atmosphere to provide a single analytic model for climatological average temperature and density profiles under various geophysical conditions. The model uses Handbook for MAP 16 tabulations for the lower atmosphere, supplemented by historical rocket and incoherent scatter data in the upper mesosphere and lower thermosphere, and represents major atmospheric variations with low‑order spherical harmonics and Fourier series in latitude, annual, semiannual, local time, and longitude. The model fits lower‑atmosphere temperature data with a 3 K standard deviation and pressure data with 2 %, and comparisons with rocket and other observations show it reasonably represents the climatological average, though discrepancies exist near the mesopause.

Abstract

The MSIS‐86 empirical model has been revised in the lower thermosphere and extended into the mesosphere and lower atmosphere to provide a single analytic model for calculating temperature and density profiles representative of the climatological average for various geophysical conditions. Tabulations from the Handbook for MAP 16 are the primary guide for the lower atmosphere and are supplemented by historical rocket and incoherent scatter data in the upper mesosphere and lower thermosphere. Low‐order spherical harmonics and Fourier series are used to describe the major variations throughout the atmosphere including latitude, annual, semiannual, and simplified local time and longitude variations. While month to month details cannot be completely represented, lower atmosphere temperature data are fit to an overall standard deviation of 3 K and pressure to 2%. Comparison with rocket and other data indicates that the model represents current knowledge of the climatological average reasonably well, although there is some conflict as to details near the mesopause.