Response of ionospheric electron temperature to solar wind dynamic pressure from Pioneer Venus.

Variations in electron temperature at an altitude of 250 km for various values of solar wind dynamic pressure varying from 2 x 10 to the -8th to about 1.7 x 10 to the -7th dynes/sq cm are examined using an electron temperature probe and magnetometer measurements from Pioneer Venus Orbiter. It is shown that there is a definitive relationship between the two parameters, with T(e) varying from 3000 K to more than 10,000 K in this dynamic pressure range. It is concluded that T(e) in the Venus ionosphere is largely controlled by solar wind conditions.