Publication Date:
2011-08-24
Description:
During the final, low solar activity phase of the Pioneer Venus (PV) mission, the Orbiter Ion Mass Spectrometer (OIMS) measurements found all ion species, in the midnight-dusk sector, reduced in concentration relative to that observed at solar maximum. Molecular ion species comprised a greater part of the total ion concentration as O(+) and H(+) had the greatest depletions. The nightside ionospheric states were strikingly similar to the isolated solar maximum 'disappearing' ionospheres. Both are very dynamic states characterized by a rapidly drifting plasma and 30-100 eV superthermal O(+) ions.
Keywords:
LUNAR AND PLANETARY EXPLORATION
Type:
Geophysical Research Letters (ISSN 0094-8276); 20; 23; p. 2735-2738
Format:
text