English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Open

Presents the pdf analysis as premium feature

PDF Analysis

Insights

Presents the summarisation as premium feature

Summarisation

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

Previous investigations have employed more than 100 close observations ofTitan by the Cassini orbiter to elucidate connections between the productionand distribution of Titan's vast, organic-rich chemical inventory and itsatmospheric dynamics. However, as Titan transitions into northern summer, thelack of incoming data from the Cassini orbiter presents a potential barrier tothe continued study of seasonal changes in Titan's atmosphere. In our previouswork (Thelen et al., 2018), we demonstrated that the Atacama LargeMillimeter/submillimeter Array (ALMA) is well suited for measurements ofTitan's atmosphere in the stratosphere and lower mesosphere (~100-500 km)through the use of spatially resolved (beam sizes <1'') flux calibrationobservations of Titan. Here, we derive vertical abundance profiles of four ofTitan's trace atmospheric species from the same 3 independent spatial regionsacross Titan's disk during the same epoch (2012 to 2015): HCN, HC$_3$N,C$_3$H$_4$, and CH$_3$CN. We find that Titan's minor constituents exhibit largelatitudinal variations, with enhanced abundances at high latitudes compared toequatorial measurements; this includes CH$_3$CN, which eluded previousdetection by Cassini in the stratosphere, and thus spatially resolved abundancemeasurements were unattainable. Even over the short 3-year period, verticalprofiles and integrated emission maps of these molecules allow us to observetemporal changes in Titan's atmospheric circulation during northern spring. Ourderived abundance profiles are comparable to contemporary measurements fromCassini infrared observations, and we find additional evidence for subsidenceof enriched air onto Titan's south pole during this time period. Continuedobservations of Titan with ALMA beyond the summer solstice will enable furtherstudy of how Titan's atmospheric composition and dynamics respond to seasonalchanges.

Abundance Measurements of Titan's Stratospheric HCN, HC$_3$N, C$_3$H$_4$, and CH$_3$CN from ALMA Observations