Abstract
One global-scale dust storm and two larger-than-average regional-scale
dust storms have been recorded by spacecraft observations within the
dust seasons of the past two Mars years. Each of these storms began near
times when the orbit-spin coupling torques on Mars were changing most
rapidly. While a clear association between Martian planet-encircling
dust events and orbital torque episodes has been established
(JGR-Planets 125, e2019JE006077), possible relationships between
orbital/dynamical variability and regional-scale storm occurrence have
not previously been investigated. In this study we compare the
initiation periods and early development of the MY 34 “C” storm and
the MY 35 “A” storm with prior findings obtained for the
planet-encircling dust event of MY 34. We employ observations by MRO’s
Mars Climate Sounder to compare dust loading, atmospheric temperatures,
dynamical heating indices, and dust layer peak altitudes, to illuminate
the similarities and differences between these events, in juxtaposition
with a discussion of the concurrent variability of the planetary orbital
angular momentum and the resulting torque on Mars.