Atmospheric rotational effects on Mars based on the NASA Ames general circulation model

Atmospheric rotational effects on Mars are computed and analyzed. Both axial (ΔLOD) and equatorial effects (polar motion) are evaluated. Surface values of stress and pressure from the NASA Ames general circulation model are used as inputs to compute the topographic, stress, and gravitational torques. Time series for the ice caps moments of inertia and the axial component of atmospheric angular momentum provide inputs for a separate computation of axial effects. Stress torque dominates the torque budget. This is different from the results obtained from Earth atmospheric models, in which pressure effects are paramount. Axial torque and ice caps yield annual and semiannual ΔLOD amplitudes of 0.747 and 0.121 ms, respectively. Torque‐induced polar motion reaches a maximum of 16.26 mm in the second half of the Martian northern hemisphere winter. Changes in LOD using the angular momentum approach are 0.187 and 0.136 ms for the annual and semiannual harmonics. The expected precision of the planned NetLander Ionospheric and Geodesic Experiment (NEIGE) should detect the main harmonics in the ΔLOD time series. Annual and semiannual polar motion harmonics induced by atmospheric torque are below the level of NEIGE detectability.