Orbit-Spin Coupling And Martian Early-Season Globalscale Dust Storms: Challenges And Opportunities
J. H. Shirley , Torquefx, Simi Valley, Ca, Usa, J. M. Battalio, Department Of Geology And Geophysics,
Yale University, New Haven, Ct, Usa, D. M. Kass, Jet Propulsion Laboratory, Pasadena Ca, Usa, A.
Kleinböhl, Jet Propulsion Laboratory, Pasadena Ca, Usa, N. G. Heavens, Space Science Institute, Boulder,
Co, Usa, S. Piqueux, Jet Propulsion Laboratory, Pasadena Ca, Usa, S. Suzuki, Jet Propulsion Laboratory,
Pasadena Ca, Usa, D, J. Mccleese, Synoptic Sciences, Pasadena, Ca, Usa, J. T. Schofield, Jet Propulsion
Laboratory (Retired), Pasadena Ca, Usa.
Introduction: The Seven Known Martian Earlyseason Global Dust Storms (Gds) Of The Historic Record Have At Least Two Things In Common: In Addition
To Their Early Inception Dates (Ls<235°), All Seven
Occurred During Intervals When Martian Orbit-Spin
Coupling Torques Were Rapidly Changing (Fig. 1).

Of Ls=201° (Versus An Observed Date Of Ls=208°).
Orbit-Spin Coupling Accelerations (Shirley, 2017)
Were Included Within The Dynamical Core Of The
Marswrf Mgcm For That Study. Century-Long
Model Runs Performed In This Configuration Replicated
The Historic Record Of Mars Years With And Without
Gds With A Hindcast Success Rate Of Nearly 80%
(Shirley, Newman Et Al., 2019). The Temporal Alignment Between Mgcm Simulations And Historic Gds