Abstract
We present new evidence for active coastal and oceanic features in Titan's Punga Mare observed in a high-phase Cassini Visual Infrared and Mapping Spectrometer observation of sun glint from the T110 flyby. We observe sunglint in a coastal channel, Apanohuaya Flumen, resulting from differing pixel contributions of land adjacent to the liquid-filled channel. Along the eastern shoreline, we identify a 5 μm bright margin. A possible explanation for this brightening includes a coastal margin of capillary wave fields. We find additional evidence of variegated sea surface roughness in Fundy Sinus and isolated Sun glitter near Hawaiki Insulae. RADAR observations of debouches (where rivers meet bays) within Punga Mare overlap several bright 5 μm pixels that indicate rough liquid surfaces. We postulate that a change in liquid flow regimes, possibly occurring as surface streamflow or bubble outburst events, may be responsible for surface roughness near these debouches. These observations imply air–sea–land interactions and active hydrology represented by possible streamflow are present in Titan's sea district during the northern summer.