Earth-like thermal and dynamical coupling processes in the Martian climate system

Abstract

The burst of Mars exploration in the past two decades has significantly improved our knowledge of the Martian atmosphere. A variety of complementary, multiannual observational records have revealed Earth-like cycling of dust and water through the Mars system, as well as hints of dynamical coupling between the lower, middle, and upper atmosphere involving deep convection, planetary waves, thermal tides, and gravity waves that can be analogous to, but sometimes very different from, coupling processes in the Earth's atmosphere. This review focuses on several essential coupling processes on Mars involving the dust/water cycling and wave activity: (1) interaction between the dust cycle, water cycle and wave activity in the lower atmosphere; (2) the global meridional circulation and middle atmospheric polar warmings; and (3) vertical coupling throughout the atmosphere during dusty/non-dusty conditions. Most of these processes have been studied with state-of-the-art numerical models validated with recent observations. In addition, we summarize several newly proposed hypotheses that potentially impact our understanding of major issues in planetary science such as atmospheric coupling, water escape, or mesospheric cloud formation. We find many similarities between wave-induced couplings on Earth and Mars and analogies between the Earth's water cycle and Mars's dust cycle, which provide insights into comparative studies of these two planets.