Ground-Based Measurements of Joule Heating Rates
Abstract
Joule heating in the upper atmosphere is the most important energy dissipation process between the magnetosphere and the ionosphere. In this paper we examine the various terms in the equation that governs Joule heating. (1) The ionospheric electric field seasonal dependence is examined. It is found that the shape of the ionospheric plasma convection cells, and the latitude of the reversal from sunward to antisunward convection, are seasonally dependent. Statistical averages of the square of the ion velocity show a maximum in fall, and a minimum in summer. (2) Pedersen conductivities at F region altitudes are examined using Chatanika and Sondrestrom radar data. It is shown that during solar minimum conditions, the F region contributes less than 20% to the total height integrated Pedersen conductivity sigma p. In contrast, during solar maximum conditions the contribution to sigma from solar produced F-region ionization can be 60%. (3) The importance of the neutral wind term in Joule heating calculations is illustrated using a specific example. The Joule heating calculated by including the neutral wind term is 2 to 4 times smaller than that calculated without the neutral wind. But the reverse can also be true, as shown during a period when the neutral wind played the role of a dynamo in the ionosphere/magnetosphere current. Ionosphere, Joule heating, Incoherent scatter radar, Ionospheric currents, Neutral winds.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 03, 1989
- Accession Number
- ADA206816
Entities
People
- O. De La Beaujardiere
- Robert L. Johnson
- V. B. Wickwar
Organizations
- SRI International