Source rates and ion recycling rates for Na and K in Mercury's atmosphere

Details Source rates and ion recycling rates for Na and K in Mercury's atmosphere Source rates and ion recycling rates for Na and K in Mercury's atmosphere

Sep 2004

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2004icar..171....1k&link_type=abstract

Icarus, Volume 171, Issue 1, p. 1-19.

Computer Science

45

Mercury, Surface, Atmosphere

Scientific paper

The supply rates of Na and K to the atmosphere of Mercury by processes acting on the extreme surface-thermal vaporization, photon-stimulated desorption (PSD), and ion-sputtering-are limited by the rates at which atoms can be supplied to the extreme surface by diffusion from inside the regolith grains. Supply rates to the atmosphere are further regulated by ion retention and by gardening rates that supply new grains to the surface. We consider the limits on supply of sodium and potassium atoms to the atmosphere, and rates of photoion recycling to the surface. Thermal vaporization rates are severely limited by the ability of atoms to diffuse to the surface of the grain. Therefore, the diffusion-limited thermal vaporization rates on Mercury's surface are comparable to or less than the PSD rates. Ion sputtering is primarily due to highly ionized heavy ions, even though they represent a small fraction of the solar wind. We have shown that up to 60% of the Na photoions are deposited on the surface of Mercury. Ion recycling to the surface can have a long-term effect on the regolith abundance if an average recycling pattern persists such that more ions return to a particular area than are launched there. It is unknown whether the formation of latitude bands of >100% ion retention persist on average despite a rapidly changing magnetosphere. The total exospheric column of sodium observed at Mercury between 1997 to 2003 varied by a factor of 2-3 from perihelion to aphelion.

Affiliated with

Also associated with

No associations

Rating

Source rates and ion recycling rates for Na and K in Mercury's atmosphere 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 Source rates and ion recycling rates for Na and K in Mercury's atmosphere, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Source rates and ion recycling rates for Na and K in Mercury's atmosphere will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-796783