The thermosphere

Abstract

The influence of thermal conductivity on the temperature distribution in the thermosphere is discussed. It is inferred that the temperature gradient probably falls off rapidly above the base of the F 1 layer instead of remaining almost constant up to great altitudes, as is often assumed. The view that the temperature near the 250 km level is only about 800°K (as suggested by rocket and radio measurements) and the view that the temperature in the exosphere is at least 1500°K (as deduced from the generally accepted theory of the escape of atmospheric helium) appear irreconcilable.