Long-term observations of southern winters on Mars: Estimations of column thickness, mass, and volume density of the seasonal CO2 deposit from HEND/Odyssey data

In this paper, we have analyzed neutron spectroscopy data gathered by the High Energy Neutron Detector (HEND) instrument on board Mars Odyssey for two Martian years of orbital mapping. We focused on the observations of the Martian southern seasonal cap for this period of time. Nuclear methods based on numerical modeling allow us to derive an estimation of the distribution of CO2 frost column density and mass from the temporal variations of neutron flux between summer and winter seasons. We have estimated the seasonal behavior of both the column density and mass of CO2 frost. Comparison between two Martian years revealed minor (