Planetary Science Seminar spring-2016

Tropical Precipitation on Slowly Rotating Planets

One of the most prominent features of the Earth's large-scale circulation in low latitudes is the intertropical convergence zone (ITCZ), where tropical precipitation is concentrated in a relatively narrow latitudinal band that moves seasonally. On Earth, the ITCZ is limited to low latitudes; however on Mars and Titan, it has been argued that analogous convergence zones can migrate significantly off the equator into the summer hemisphere, perhaps even reaching the summer pole in the case of Titan. Previous studies of the ITCZ’s extent have focused primarily on thermodynamics, particularly emphasizing its collocation with maximum surface temperature and its response to local surface heat capacity. Here, we focus on the dynamical mechanisms controlling ITCZ migrations, examining the ITCZ’s extent through the perspective of the momentum budget and offering a new view on the seasonal weather patterns of terrestrial planets.