The current weather and climate of Mars: 12 years of atmospheric monitoring by the Planetary Fourier Spectrometer on Mars Express

We used thermal-infrared spectra returned by the Mars Express Planetary Fourier Spectrometer (PFS/MEx) to retrieve atmospheric temperature profiles, surface temperatures, and column-integrated optical depths of dust and water ice. More than 2,500,000 spectra were processed to build this new atmospheric dataset, covering the full range of season, latitude, longitude, and local time. The data presented here span more than six Martian Years (from MY 26, Ls = 331°, 10 January 2004 to MY 33, Ls = 78°, 6 December 2015). We present an overview of the seasonal and latitudinal dependence of the above atmospheric quantities for the relevant period, as well as an assessment of the interannual variability in the current Martian climate. The general effect of suspended dust on atmospheric temperatures observed during the global dust storm of MY 28 is also presented. Atmospheric temperatures and aerosol opacity were successfully retrieved over cold surface areas and in the polar regions, including the polar nights. Rather than the aphelion cloud belt, the most prominent feature one can observe in the climatology of the Martian water ice clouds is the seasonal extent, pattern and thickness of the North polar hoods (NPH), where most of the thickest clouds are observed. The NPH also shows peculiar features, observed in detail here for the first time, with characteristic spatial and seasonal patterns that repeat very similarly every Martian year. By exploiting PFS/MEx capability to perform observations at different local times (LT), this dataset allowed the characterization of how dust and ice cloud optical depths vary throughout the day on Mars. We present observations of the dust daily cycle during non-dusty seasons; the daily variation of water ice opacity in the aphelion cloud belt; and the diurnal variation of the North and South polar hoods. With unprecedented spatial and temporal coverage and details revealed, this dataset offers new challenges to the Martian global circulation models and, at the same time, a new reference for the MYs complementary to those observed by previous orbiters.