Evolution of Titan's Stratospheric HCN in High Spatial Resolution

Saturn’s largest moon, Titan, is the only moon in our solar system with a substantial atmosphere. Like Earth, Titan’s atmosphere comprises mostly Nitrogen but is also host to many hydrocarbon and nitrile species, produced by photochemistry in the upper atmosphere. These species are good tracers of atmospheric dynamics.

From 2004 to 2017, NASA/ESA’s Cassini-Huygens spacecraft explored the Saturn system, performing 127 flybys of Titan. On its third flyby, Cassini released the ESA-operated Huygens atmospheric entry probe, which performed measurements on its descent to Titan’s surface. Cassini’s Composite Infrared Spectrometer (CIRS) observed Titan in the infrared for 13 years, almost half a Titan year. We use nadir observations acquired by the CIRS instrument at low spectral resolution to map trace species in Titan’s stratosphere at high spatial resolution. In-situ measurements acquired by the Huygens probe constrain our atmospheric retrievals. We use trace gas distributions to investigate seasonal changes in dynamics near Titan’s stratospheric equator.