Simulation Of The H Escape Variability With A Global Climate Model.
F. GonzáLez-Galindo, Instituto De Astrofı́Sica De Andalucı́A-Csic, Granada, Spain (Ggalindo@Iaa.Es), J.-Y.
Chaufray, Latmos, Paris, France, G. Gilli, A. Brines, M.A. LóPez-Valverde, Instituto De Astrofı́Sica De Andalucı́Acsic, Granada, Spain, F. LefèVre, M. Vals, F. Montmessin, L. Rossi, Latmos, Paris, France, F. Forget, E. Millour,
Lmd, Paris, France.

Introduction
The Geological Evidences Show That Liquid Water Was
Present In Mars Surface About 4 Billions Year Ago, Implying That The Martian Atmosphere At That Time Was Denser,
Wetter, And Probably Warmer Than It Is Today (Haberle
Et Al., 2017). Atmospheric Escape To Space Is Thought To
Have Been The Main Loss Process Of The Ancient Martian
Atmosphere And Water, Driving The Atmospheric Evolution Resulting In The Current Thin Atmosphere With A Dry
And Cold Climate (Brain Et Al., 2017). The Large Abundance Of Deuterium (D/H Ratio) In Mars When Compared
To The Terrestrial Values Suggests That The Thermal (Jeans)
Escape Of Hydrogen From Mars Has Been A Major Loss
Mechanism Of The Ancient Martian Water. Understanding
Current Escape To Space, In Particular H Thermal Escape,
And Its Links With The Different Processes Operating In The
Martian Atmosphere, Is Thus Mandatory In Order To Have A
Better And More Precise View Of The Long-Term Evolution