Solar cycle variation of the upper atmosphere temperature of Mars
- Univ. of Graz (Austria)
Neutral gas temperatures inferred from topside plasma scale heights of electron density distributions obtained from observations by US and USSR Mars missions imply a much higher dependence of solar activity (expressed by the 10.7 cm radio flux F{sub 10.7}) than that found for Venus. This dependence, however, does not appear to be consistent with the observed solar cycle dependence of ionospheric peak plasma densities. The reason for this discrepancy seems to lie in the fact, that photochemical equilibrium applies only to altitudes below 170 km, whereas topside scale heights are usually derived for a much greater altitude range and thus may be modified by transport and other processes. If scale heights are obtained by matching a Chapman-layer to plasma density profiles near the ionosphere peak, the derived neutral temperatures show a much weaker dependence on F{sub 10.7}, in fact one essentially the same as for Venus. Thus, the response of the upper atmosphere for Mars, at least near the ionospheric peak, appears to be virtually identical to that of Venus.
- OSTI ID:
- 6050747
- Journal Information:
- Geophysical Research Letters (American Geophysical Union); (USA), Vol. 16:5; ISSN 0094-8276
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
MARS PLANET
PLANETARY ATMOSPHERES
DATA ANALYSIS
ELECTRON DENSITY
PHOTOCHEMICAL REACTIONS
PLANETARY IONOSPHERES
PLASMA DENSITY
SOLAR ACTIVITY
TEMPERATURE DEPENDENCE
VARIATIONS
VENUS PLANET
ATMOSPHERES
CHEMICAL REACTIONS
PLANETS
640107* - Astrophysics & Cosmology- Planetary Phenomena