Interannual observations and quantification of summertime H2O ice deposition on the Martian CO2 ice south polar cap

摘要: Abstract The spectral signature of water ice was observed on Martian south polar cap in 2004 by the Observatoire pour l'Mineralogie, l'Eau les Glaces et l'Activite (OMEGA) ( Bibring al., ). Three years later, OMEGA instrument used to discover deposited during southern summer Langevin 2007 However, temporal and spatial variations these signatures have remained unexplored, origins deposits remains an important scientific question. To investigate this question, we observations from Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) Orbiter (MRO) spacecraft austral over four search amount ice. We report below that each year cap, magnitude H2O has risen steadily throughout summer, particularly west end cap. extent deposition is disagreement with current best simulations Montmessin This increase most likely caused atmospheric a set unusual conditions makes quantification transport flux using CRISM close ideal. calculate ‘minimum apparent‘ corresponding thin layer 0.2 mm (with 70% porosity). 0.6–6% total budget. compare our apparent’ previous estimates. process may also implications formation stability CO2 therefore play significant role climate budget modern day Mars.