Abstract

A regional dust storm was observed in the northern spring of Martian Year 35, a period characterized by a relatively cold and clear atmosphere. Both satellite observations and general circulation model simulations reveal that the atmospheric temperature response characteristics of this early regional dust storm closely resemble the equatorial mirror of the C-type regional dust storm responses in the Northern Hemisphere winter. Atmospheric heating in the dust-lifting region was primarily driven by shortwave radiative heating of dust particles. Anomalous cooling in the northern mesosphere and heating responses in the southern troposphere were associated with dust-modulated gravity waves and planetary waves, respectively. The anomalous atmospheric waves during the dust storm significantly enhanced the meridional circulation. Inhomogeneous heating due to dust distribution enhanced southward meridional circulation in the lower tropical troposphere, where the water vapor mixing ratio increased. As a result, the meridional water transport significantly increased from the Northern to the Southern Hemisphere during the dust event. Furthermore, the water transport during the E Event showed significant longitudinal asymmetry, highlighting the importance of the stationary eddy transport term.