A Global and Seasonal Perspective of Martian Water Vapor From ExoMars/NOMAD

Abstract

Slightly less than a Martian Year of nominal science (March 2018–January 2020) with the ExoMars Trace Gas Orbiter has furthered the ongoing investigation of dayside water vapor column abundance. These dayside observations span latitudes between 75°S and 75°N, and all longitudes, which can provide global snapshots of the total water column abundances. In addition to tracking the seasonal transport of water vapor between poles, geographic enhancements are noted, particularly in the southern hemisphere, both in Hellas Basin, and in other regions not obviously correlated to topography. We report consistent water vapor climatology with previous spacecraft observations, however, note a difference in total water vapor content is noted. Finally, we are unable to find evidence for substantial diurnal variation in the total dayside water vapor column.