Are tropical cyclones possible over Titan’s polar seas?

While extratropical cyclones cannot be expected in Titan’s barotropic troposphere, tropical cyclones which gain their energy from the latent heat of sea evaporation cannot be entirely dismissed over Titan’s polar hydrocarbon seas. The most essential condition for the genesis of tropical cyclones on Titan is a methane-rich composition of the polar seas. The most likely season for Titan’s hypothetical tropical cyclones is around the northern summer solstice when the sea surface gets warmer and the relative vorticity of the near-surface air increases by seasonal convergence and equatorial wave activity. A tropical cyclone would manifest itself as an anti-clockwise swirling vortex right over one of the northern seas (Kraken Mare, Ligeia Mare, Punga Mare) and increase the surface wind over the seas by an order of magnitude. On the other hand, tropical cyclones are unlikely to emerge over Titan’s few tropical lakes for dynamic reasons such as negligible Coriolis parameter and large vertical wind shear.

► Titan’s northern polar sea area may be conducive to tropical cyclones. ► Tropical cyclones could develop in summer if the seas are methane-rich. ► The dynamics of Titan’s polar region is more conducive to tropical cyclones.