Titan's Prevailing Circulation Might Drive Highly Intermittent, Yet Significant Sediment Transport

Titan, the largest moon of Saturn, is characterized by gigantic linear dunes and an active dust cycle. Much like on Earth, these aeolian processes are caused by the wind-driven saltation of surface grains. It is still unclear, however, how saltation on Titan can occur despite the typically weak surface winds and the potentially cohesive surface grains. Here, we explore the hypothesis that saltation on Titan may be sustained at lower wind speeds than previously thought, primarily through granular splash rather than aerodynamic lifting of surface grains. We propose a saltation mass flux parameterization for Titan and use it to quantify sediment transport with a general circulation model. The results suggest that Titan's prevailing circulation can generate highly intermittent yet significant saltation, with mass fluxes of the order of 10(4) kg m(-1) year(-1), and that Titan dunes may be formed primarily by fine grains, approximately 0.1 mm in size.

Automated summary

Titan, Saturn's largest moon, has huge linear dunes and an active dust cycle. Similar to Earth, these aeolian processes are caused by wind moving surface grains. However, it is still unclear how saltation can occur on Titan with its weak winds and potentially cohesive grains. This study suggests that saltation may occur on Titan through granular splash instead of aerodynamic lifting, and the prevailing circulation on Titan can generate significant yet intermittent saltation.