Structure of the ionized lunar sodium and potassium exosphere: Dawn-dusk asymmetry
Article first published online: 17 APR 2014
©2014. American Geophysical Union. All Rights Reserved.
Journal of Geophysical Research: Planets
Volume 119, Issue 4, pages 798–809, April 2014
How to Cite
2014), Structure of the ionized lunar sodium and potassium exosphere: Dawn-dusk asymmetry, J. Geophys. Res. Planets, 119, 798–809, doi:10.1002/2013JE004529., et al. (
- Issue published online: 13 MAY 2014
- Article first published online: 17 APR 2014
- Accepted manuscript online: 18 MAR 2014 06:19PM EST
- Manuscript Accepted: 13 MAR 2014
- Manuscript Revised: 4 MAR 2014
- Manuscript Received: 16 SEP 2013
- lunar exosphere;
- pickup ions;
We present latitude and longitude distributions of Na+ and K+ fluxes from the Moon derived from Kaguya low-energy ion data. Although the latitude distribution agrees with previous ground-based telescope observations, dawn-dusk asymmetry has been determined in the longitude distribution. Our model of the lunar surface abundance and yield of Na and K demonstrates that the abundance decreases to approximately 50% at dusk compared with that at dawn due to the emission of the exospheric particles assuming the ion fluxes observed by Kaguya are proportional to the yield. It is also implied that the surface abundance of Na and K need to be supplied during the night to explain the observed lunar exosphere with dawn-dusk asymmetry. We argue that the interplanetary dust as well as grain diffusion and migration/recycling of the exospheric particles may be major suppliers.