Changes in trace gas abundances over Titan's south pole
Observations taken with the Composite Infrared Spectrometer (CIRS) on Cassini clearly demonstrate a large increase in trace gas emission at the south pole between late 2010 and early 2011. These changes have been linked with the onset of atmospheric subsidence after the equinox of August 2009.
The left panel shows the measurements obtained in January 2010 at a latitude of -75.8 degrees and a tangent altitude of 448 km; the right panel shows the measurements obtained in September 2011 at a latitude of -83.8 degrees and a tangent altitude of 457 km. The tangent altitude is the closest distance reached by the line-of-sight vector.
A number of trace compounds were detected: diacetylene (C4H2), methylacetylene(C3H4), cyanoacetylene (HC3N), carbon dioxide (CO2), benzene (C6H6), hydrogen cyanide (HCN) and acetylene (C2H2).
For further details, see N. Teanby et al. (2012)