P13D-04
H Escape in 3D: MAVEN IUVS observations of the Mars corona
Monday, 14 December 2015: 14:25
2009 (Moscone West)
Michael Chaffin1, Jean-Yves Chaufray2, Justin Deighan1, Nicholas McCord Schneider3, William E. McClintock1, Ian F Stewart1, Ed Thiemann1, John T Clarke4, Greg Holsclaw1, Sonal Jain5, Matteo Michael James Crismani1, Arnaud Stiepen3, Franck Montmessin2, Francis Gerard Eparvier3, Phillip C Chamberlin6 and Bruce Martin Jakosky1, (1)Laboratory for Atmospheric and Space Physics, Boulder, CO, United States, (2)LATMOS Laboratoire Atmosphères, Milieux, Observations Spatiales, Paris Cedex 05, France, (3)University of Colorado at Boulder, Boulder, CO, United States, (4)Boston University, Boston, MA, United States, (5)University of Colorado at Boulder, LASP, Boulder, CO, United States, (6)NASA Goddard Space Flight Center, Greenbelt, MD, United States
Abstract:
Mars has lost a significant fraction of its initial water inventory to space, as evidenced by surface morphology and an enrichment of the heavy isotope deuterium relative to hydrogen. This loss continues today via thermal Jeans escape of neutral hydrogen from the extended H corona. The Mars Atmosphere and Volatile EvolutioN mission's Imaging Ultraviolet Spectrometer IUVS constrains this escape with high cadence, spatially resolved measurements of the corona in scattered sunlight in the Lyman alpha line of neutral H at 121.6 nm. These measurements indicate spatial variability in the corona never before recognized, with potential effects on reconstructing the escape history of water and on retrieved escape rates from previous spatially unresolved observations. I will present our current progress in retrieving escape rates and density distributions from the IUVS observations, including the degree to which observations of the H corona can constrain the thermospheric general circulation at Mars.
