AIR DENSITY AT HEIGHTS NEAR 190 KM IN 1966-7, FROM THE ORBIT OF SECOR 6.
ROYAL AIRCRAFT ESTABLISHMENT FARNBOROUGH (ENGLAND)
Pagination or Media Count:
The air density at a height of 191 km between 14 June 1966 and 5 July 1967 has been evaluated by analyzing the orbit of the satellite Secor 6 1966-51B. The 154 values of density obtained show that nearly all geomagnetic disturbances are accompanied by increases in density, of larger magnitude than expected. Surprisingly, however, the strong 27-day recurrence tendencies in solar activity, as represented by the 10.7-cm radiation energy, are quite absent from the density variations. When the effect of the day-to-night variation is removed, the most important variation in air density at 191 km during 1966-7 is found to be a semi-annual oscillation, with the maximum density, in October 1966 and April 1967, exceeding the minimum, in July 1966 and January 1967, by a factor of 1.45. This semi-annual variation, which is very similar in form to that found at a height of 1130 km from Echo 2, has during 1966-7 displaced solar activity as the main source of atmospheric variation at heights near 200 km. Author
- Atmospheric Physics
- Unmanned Spacecraft