Stable Existence of Tropical Endorheic Lakes on Titan

Abstract

Cassini detected numerous hydrocarbon seas/lakes in the polar region of Titan and wide areas of sand seas in the tropical region, which initially led to the perception that Titan's tropical region may be too dry for lakes. Yet, a few tropical lakes were possibly seen on Cassini's near-infrared images, while they were not seen by other imaging instruments. This study shows by a lake balance model in combination with a global climate model and global topography map that a few lakes can perennially exist in Titan's tropical drainage basins of Shangri-La, Tui Regio, and Hotei Regio. This is possible because the lakes are fed by precipitation in a huge catchment area, while efficient lake evaporation occurs only in a small area inside of deep topographic depressions. However, tropical lakes may occasionally desiccate due to orbitally forced changes in tropical precipitation.