Abstract
Observations made in Gale Crater by instruments on the MSL Curiosity
Rover show that the diurnal amplitude of the surface pressure is
increased and the depth of the Convective Boundary Layer (CBL) is
decreased relative to other lander locations on flatter regions of Mars
(Haberle et al., 2014; Moores et al., 2015). Mesoscale modeling studies
of Gale Crater suggest that crater circulations produce these effects.
Tyler & Barnes (2013) show that local upslope/downslope flows along the
crater rim and Mt. Sharp amplify the diurnal pressure cycle. These same
flows are thought to be at least partly responsible for the suppression
of the CBL because upward air flow at the rim and in the center (due to
Mt. Sharp) forces subsidence over the lowest regions of the crater
during the day. Regional flows, largely due to the location of Gale near
the dichotomy boundary, may also play a role in shaping the circulation
internal to the crater. Whether the behavior of the CBL and the
amplified diurnal pressure cycle are phenomena observed in craters
morphologically different from Gale (i.e. bowl-shaped, irregular,
degraded) is not yet understood. We will explore these questions by
characterizing the behavior of these processes as they are shaped by the
morphology of craters greater than 100 km in diameter. We use the NASA
Ames Mars Global Circulation Model (GCM) that now utilizes the NOAA/GFDL
cubed-sphere finite-volume dynamical core to examine
~100 craters of varying size and shape from a database
of known Martian craters (Robbins & Hynek, 2014). Run at 7.5 km
resolution, the GCM is capable of resolving surface winds, temperature,
and pressure inside craters of this size allowing for the analysis of
dozens of craters simulated at various seasons and within the context of
synoptic and global-scale phenomena.