Fully-Coupled Photochemical Modeling Of The Deuterated
Ionosphere And Non-Thermal Escape Of D.
E. M. Cangi, Laboratory For Atmospheric And Space Physics (Lasp), University Of Colorado Boulder, Usa
(Eryn.Cangi@Colorado.Edu), M. S. Chaffin, J. Deighan, B. Gregory, Lasp, Colorado, Usa, R. V. Yelle, Lunar And
Planetary Laboratory, Arizona, Usa.

Introduction
Context: The Mars Water D/H Ratio Is 5-6 × The Earth

Ratio, And Is Considered To Be An Indicator Of Past Water
Loss On Mars. Because The Isotope D Is Heavier Than H,
Thermal Escape Is Less Effective For D, And Escape Of D
Is Expected To Occur Primarily Via Non-Thermal Escape
Driven By Ion Processes. Neutral H Loss From Both Thermal And Non-Thermal Processes Is Well-Studied At Mars,
But The Deuterated Ionosphere Is Relatively Unstudied.
This Leaves Us With A Lack Of Understanding Of The True
Scale Of Non-Thermal D Escape And Its Variation Throughout Time.
Aims: To Fill This Knowledge Gap, We Have Performed
A Modeling Study Of The Deuterated Ionosphere At Mars.
Our Primary Goals Are To Characterize The Overall Composition Of The Deuterated Ionosphere, Quantify The Thermal