Strong Localized Pumping of Water Vapor to High Altitudes on Mars During the Perihelion Season
Aoki, S.; Vandaele, A. C.; Daerden, F.; Villanueva, G. L.; Liuzzi, G.; Thomas, I. R.; Erwin, J. T.; Trompet, L.; Ristic, B.; Patel, M. R.; Bellucci, G.; Forget, F.; López-Valverde, M. A.; González-Galindo, F.; Funke, B.; Belyaev, D. A.; Lopez-Moreno, J. J.; Holmes, J. A.; Brines, A.; Grabowski, U.; Rodriguez-Gomez, J.
Spain, Belgium, Japan, United States, United Kingdom, Russia, Germany, France, Italy
Abstract
Here we present water vapor vertical profiles observed with the ExoMars Trace Gas Orbiter/Nadir and Occultation for MArs Discovery instrument during the perihelion and Southern summer solstice season (LS = 240°-300°) in three consecutive Martian Years 34, 35, and 36. We show the detailed latitudinal distribution of H2O at tangent altitudes from 10 to 120 km, revealing a vertical plume at 60°S-50°S injecting H2O upward, reaching abundance of about 50 ppmv at 100 km. We have observed this event repeatedly in the three Martian years analyzed, appearing at LS = 260°-280° and showing inter-annual variations in the magnitude and timing due to long term effects of the Martian Year 34 Global Dust Storm. We provide a rough estimate of projected hydrogen escape of 3.2 × 109 cm−2 s−1 associated to these plumes, adding further evidence of the key role played by the perihelion season in the long term evolution of the planet's climate.