Title: Microwave mapping of water isotopologues in the martian atmospheres with the 
SubMillimeter Array

Abstract:
HDO and H2-18O in the Martian atmosphere were observed at 203.4 and 225.9 GHz.on April 26, 
2014, close to opposition (maximum diameter 15.1” on 15 April). The season was just past 
northern summer solstice (Ls=90) when atmospheric water vapor is typically most abundant, 
especially in the northern polar regions where the column can approach 100 pr. micron. Initial 
analysis of  both maps clearly show the peak in water vapor near the North Pole as well as 
elevated levels of water vapor emission along the morning limb. Results are compared to a 
model of D/H fractionation based on multiple reservoirs, with lower ratios expected at the poles.

Co-authors:
Michael Hecht, Mark Gurwell, David Fisher, Miranda Kephart