Solar cycle variations in H(+) and D(+) densities in the Venus ionosphere - Implications for escape

Details Solar cycle variations in H(+) and D(+) densities in the Venus ionosphere - Implications for escape Solar cycle variations in H(+) and D(+) densities in the Venus ionosphere - Implications for escape

Dec 1992

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1992georl..19.2449d&link_type=abstract

Geophysical Research Letters (ISSN 0094-8276), vol. 19, no. 24, p. 2449-2452.

Physics

18

Deuterium, Hydrogen Ions, Pioneer Venus 1 Spacecraft, Planetary Ionospheres, Solar Activity, Venus Atmosphere, Abundance, Mass Spectrometers, Solar Cycles, Solar Planetary Interactions, Water

Scientific paper

The hydrogen ion concentrations recently observed on Venus, near solar minimum, by the Ion Mass Spectrometer on the Pioneer Venus Orbiter in the anti-solar sector of the ionosphere are more than an order of magnitude less than those previously observed at solar maximum. This strong solar cycle variation has a profound effect on the escape of hydrogen (and deuterium) from Venus; almost all escape occurs during solar maximum. After adjustment for solar cycle variation, a planet-averaged hydrogen escape flux of 0.6-1.4 x 10 exp 7/sq cm per sec is obtained along with a large deuterium fractionation factor of 0.1-0.14. These results suggest at least two plausible scenarios for the evolution of water on Venus: (1) water vapor on Venus may be approaching a steady state if the escape flux is balanced by endogenous sources of water or (2) the present day D/H ratio of 0.024 could be established by Rayleigh fractionation of an early low D/H water reservoir if the escape flux was sufficiently large in earlier times. An early water endowment at least 340 times today's abundance would be needed.

Affiliated with

Also associated with

No associations

Rating

Solar cycle variations in H(+) and D(+) densities in the Venus ionosphere - Implications for escape does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Solar cycle variations in H(+) and D(+) densities in the Venus ionosphere - Implications for escape, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Solar cycle variations in H(+) and D(+) densities in the Venus ionosphere - Implications for escape will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1114875