Accession Number : AD0616810

Title :   SATELLITE MEASUREMENTS OF THE DIURNAL VARIATION OF ELECTRON TEMPERATURES IN THE F REGION.

Descriptive Note : Environmental research papers,

Corporate Author : AIR FORCE CAMBRIDGE RESEARCH LABS L G HANSCOM FIELD MASS

Personal Author(s) : Sagalyn,R. C. ; Smiddy,M. ; Bhargava,Y. N.

Report Date : APR 1965

Pagination or Media Count : 25

Abstract : Simultaneous measurements of electron temperatures and densities have been obtained in the F region with spherical electrostatic analyzers mounted on two Air Force satellites with polar, nearly circular orbits. Large diurnal variations of electron temperature are observed between 200 and 330 km. This is characterized by sharp increase in electron temperature of the order of 2000 degrees within two hours after ionospheric sunrise. At ground sunset a rapid decrease of electron temperature, T, commences. The rate of change of T is, however, an order of magnitude smaller than at sunrise. After ionospheric sunset, the temperature decrease with time is greatly reduced; a minimum of 1000 = 200 K is measured before sunrise. Above 200 km, the rapid change in temperature at sunrise and sunset is accompanied by over an order of magnitude change in electron density. Below 200 km the amplitude of the diurnal variation of T decreases rapidly with altitude. Over the latitude range = 75 degrees variations of temperature with local time are greater than the variations with latitude; however, there are observed small but significant increases in temperature and charge density in the southern hemisphere which are correlated with geomagnetic position. (Author)

Descriptors :   (*ELECTRON DENSITY, DIURNAL VARIATIONS), (*DIURNAL VARIATIONS, ELECTRON DENSITY), (*METEOROLOGICAL SATELLITES, IONOSPHERE), TEMPERATURE, ELECTRONS, POLAR ORBIT TRAJECTORIES

Distribution Statement : APPROVED FOR PUBLIC RELEASE