Transport And Escape Of Water: Toward A More Complete
Interpretation With Tgo Nomad And Maven Ngims.
S. W. Stone, G. L. Villanueva, G. Liuzzi, M. Benna, P. R. Mahaffy, M. K. Elrod, Nasa Goddard Space Flight
Center, Greenbelt, Md, Usa, R. V. Yelle, Lunar And Planetary Laboratory, University Of Arizona, Tucson, Az, Usa.

Introduction
The Present-Day Transport, Destruction, And Subsequent
Loss To Space Of H2 O In The Martian Atmosphere Has
Important Implications For Our Understanding Of The Evolution Of The Martian Atmosphere And Climate Through
Time.[1] On Earth, Most H2 O Is Trapped Relatively Close
To The Surface By An Efficient Hygropause. In Contrast, On
Mars The Hygropause Is Often Transgressed By Significant
Amounts Of H2 O Transported Vertically From The Lower Atmosphere Around Perihelion, Corresponding To Southern
Hemisphere Summer, During Regional Dust Storms Which
Occur Every Martian Year, And During Global Dust Storms
Which Occur Roughly Every Ten Years.[2–8] A Portion Of
This H2 O Progresses Into The Upper Atmosphere, Where It
Is Quickly Destroyed By Ion-Neutral Reactions To Produce
H That Can Escape To Space.[7, 9] This Relatively Rapid
Transport Of H Into The Upper Atmosphere In The Form Of