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Explanation for the Increase in High‐Altitude Water on Mars Observed by NOMAD During the 2018 Global Dust Storm
Author(s) -
Neary L.,
Daerden F.,
Aoki S.,
Whiteway J.,
Clancy R. T.,
Smith M.,
Viscardy S.,
Erwin J.T.,
Thomas I. R.,
Villanueva G.,
Liuzzi G.,
Crismani M.,
Wolff M.,
Lewis S. R.,
Holmes J. A.,
Patel M. R.,
Giuranna M.,
Depiesse C.,
Piccialli A.,
Robert S.,
Trompet L.,
Willame Y.,
Ristic B.,
Vandaele A. C.
Publication year - 2020
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2019gl084354
Subject(s) - water vapor , mars exploration program , atmospheric sciences , dust storm , atmosphere (unit) , altitude (triangle) , environmental science , atmosphere of mars , storm , effects of high altitude on humans , trace gas , nadir , orbiter , occultation , geology , astrobiology , martian , meteorology , physics , satellite , oceanography , geometry , mathematics , astronomy
Abstract The Nadir and Occultation for MArs Discovery (NOMAD) instrument on board ExoMars Trace Gas Orbiter measured a large increase in water vapor at altitudes in the range of 40–100 km during the 2018 global dust storm on Mars. Using a three‐dimensional general circulation model, we examine the mechanism responsible for the enhancement of water vapor in the upper atmosphere. Experiments with different prescribed vertical profiles of dust show that when more dust is present higher in the atmosphere, the temperature increases, and the amount of water ascending over the tropics is not limited by saturation until reaching heights of 70–100 km. The warmer temperatures allow more water to ascend to the mesosphere. Photochemical simulations show a strong increase in high‐altitude atomic hydrogen following the high‐altitude water vapor increase by a few days.