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The B storm is an annually recurring, regional-scale dust storm that occurs over the south pole of Mars during southern summer solstice season during years lacking a global dust storm [1]. The B storm begins just after perihelion (Ls = 251°), reaches peak strength around southern summer solstice (Ls = 270°), and decays through ˜Ls = 290° [2]. The B storm is associated with mid-level atmospheric warming in which 50 Pa (2.5 scale heights) temperatures increase to over 200 K. Mid-level dust concentrations more than triple during the B storm, exceeding 4 ppm throughout the duration of the storm and exceeding 10 ppm at peak strength (Ls = 270°) [1,2]. Our observational analysis, which was presented at AGU in 2020, shows that elevated dust concentrations (> 4 ppm) and associated warming (> 200 K) are observable as high as 25 Pa during peak intensity, and that the B storm is a southwestward-propagating storm that develops over 60°S and strengthens as it travels poleward [2,3]. We have since carried out simulations of B storms using the NASA Ames Mars Global Climate Model (MGCM), which is based on the NOAA/GFDL cubed-sphere finite volume dynamical core, at high spatial (1x1°, 60x60 km) resolution. We find that B storm dust is lofted upwards of 50 Pa by episodic pluming events somewhat resembling the rocket dust storms described in Spiga et al. (2013) [4]. Detached dust layers sometimes form from these plumes at altitudes between 25-3 Pa (3-5 scale heights). These detached layers maintain altitude for ˜1 sol before the sedimentation rate of the dust exceeds the upward vertical velocity generated by the radiative heating of the suspended dust [5]. We will present results from the MGCM-simulated B storm using three-dimensional animations to illustrate the hourly evolution of the dust that is lofted during the storm. 1.

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