Temporal Monitoring of Hydrocarbon Lake Extents on Titan’s Ligeia Mare Based on Cassini SAR Data

Abstract. Titan is Saturn’s largest moon, which is uniquely positioned in planetary science due to its methane-based hydrological cycle and Earth-like surface processes. The temporal study of lake size variations along the western shoreline of the Ligeia Mare is conducted using Cassini SAR observations from the T29 (2007) and T108 (2015) flybys. The boundaries of the selected lakes were manually delineated using high-resolution BIDR-processed SAR imagery to quantify areal changes. The lakes included Logtak, Sevan, Vanern, and Ohrid Lacus. These lakes were chosen for their distinct visibility and distribution within the study area. A SAR mosaic was generated to compare the spatial extents of the lakes during the two-time frames. The results clearly suggest a loss in surface areas for certain lakes over the 8-year time interval and thus may suggest evaporation, infiltration, or subsurface exchange processes. Such variability in lake size provides a strong argument for an active climate system on Titan along with surface-atmosphere interactions. The study stands in favor of radar data as the effective parameter in monitoring geomorphologic changes on Titan, especially over regions obscured by the dense atmosphere, and adds to the study of Titan's methane cycle and surface evolution.