Mapping methane in Martian atmosphere with PFS-MEX data

In this study we map the methane gas in the Martian atmosphere. The main goal of this work is to show the methane behaviour across the planet seasonally. To this aim, we analyze the strongest methane band in the short wavelength channel of the Planetary Fourier Spectrometer (PFS) on board ESA Mars Express (MeX) spacecraft. The optical line depth is used to derive the column density of methane. The maps thus obtained show the spatial variability of this non-condensable gas and how the gas is transported in the atmosphere due to the cycle of carbon dioxide. Moreover, the increase of methane over the north polar cap during local summer, which cannot be explained by global circulation, strongly suggests that there could be methane reservoir associated with the polar cap. (C) 2010 Elsevier Ltd. All rights reserved.