Sources and Sinks of Energy of Traveling Waves on Mars

Large dust storms generate substantial changes to Marss circulation and thermal structure and spawn primarily from traveling baroclinic Rossby waves. Therefore, understanding the dynamics of these waves contributes to the safety of surface missions. The recent development of three Martian reanalysis datasets now enables an in-depth, cross-dataset comparison and description of traveling wave energy sources and sinks. Wave amplitudes maximize predominantly near the surface during northern hemisphere fall and winter. Short-period (1.5<P<8 Mars day) waves grow on the upstream (western) sides of basins via baroclinic energy conversion and by extracting energy from the mean flow and tides (P<1.1 Mars day). However, waves undergo a net barotropic loss of energy to the mean flow on the downstream (eastern) sides of basins and to long period (P>8 Mars day) waves. Additionally, Martian waves experience a mid-winter minimum in amplitude (dubbed the solstitial pause) despite large potential baroclinic growth rates. The largest difference across datasets emerges due to changes in the quality of observations near the surface, particularly during the solstitial pause; thus, confidence in the diagnosis of individual eddies should be held only for when the reanalyses agree.