Solar Ionizing Radiation at Mars: Predictions vs. MAVEN Observations

Tuesday, 15 December 2015
Poster Hall (Moscone South)
William K Peterson1, Edward Thiemann2, Francis Epavier3, Laila Andersson1, Davin E Larson4, David L Mitchell5, Christian Xavier Mazelle6, Joseph Scott Evans7, Juan M Fontenla8, Shaosui Xu9, Michael Warren Liemohn9, Shotaro Sakai10 and Thomas Cravens11, (1)University of Colorado at Boulder, Boulder, CO, United States, (2)Laboratory for Atmospheric and Space Physics, Boulder, CO, United States, (3)Univ Colorado, Boulder, CO, United States, (4)Space Sciences Laboratory, Berkeley, CA, United States, (5)University of California Berkeley, Berkeley, CA, United States, (6)University Paul Sabatier Toulouse III, Toulouse Cedex 09, France, (7)Computational Physics Inc, Springfield, VA, United States, (8)NorthWest Research Associates Boulder, Boulder, CO, United States, (9)University of Michigan Ann Arbor, Ann Arbor, MI, United States, (10)University of Kansas, Physics & Astronomy, Lawrence, KS, United States, (11)University of Kansas, Lawrence, KS, United States
The primary source of energy in the Martian upper atmosphere is solar ionizing radiation. The first of the many processes that convert solar radiation to thermal energy is the production of photoelectrons. Observations on the MAVEN spacecraft of both photoelectrons and broad band solar ionizing radiation allow quantitative comparison of model calculations of the photoelectron energy spectra below 200 km with observations.

We compare and contrast photoelectron energy spectra observed before and after an X class solar flare on October 19, 2014 with calculations from three photoelectron production and transport codes and solar irradiance spectra derived from both MAVEN and Earth based observations. We find good agreement between data and models