Accession Number : AD0748392

Title :   Periodic Changes in Atmospheric Variability Between 140 and 195 km.

Descriptive Note : Research rept. Jun 71-Feb 72,

Corporate Author : AEROSPACE CORP EL SEGUNDO CALIF LAB OPERATIONS

Personal Author(s) : Prag,Arthur B.

Report Date : 15 AUG 1972

Pagination or Media Count : 30

Abstract : An empirical model has been constructed to account for the large atmospheric density variations observed from the drag on OV1-15 and ATS-2 between about 140 and 195 km. There are seven statistically significant temporal terms: one involving a(p), one involving the calcium plage index, an annual term, a semi-annual term, two one-third-annual terms and a local-time term. The altitude dependence for undisturbed conditions is expressed as a sum of two exponentials. It is predicted that the amplitude of the 'semi-annual' variation will be independent of solar activity for all but the most disturbed solar conditions and that the phase of the October maximum and the January minimum will be earlier as solar activity increases. The April maximum and the July minimum will be approximately independent of solar activity. (Author)

Descriptors :   (*UPPER ATMOSPHERE, DENSITY), SCIENTIFIC SATELLITES, ORBITS, DRAG, CORRELATION TECHNIQUES

Subject Categories : Atmospheric Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE