Seasonal changes in the middle atmosphere of Titan from Cassini/CIRS observations: temperature and trace species abundance profiles from 2004 to 2017
The Cassini/Composite InfraRed Spectrometer (CIRS) instrument has been observing the middle atmosphere of Titan over almost half a Saturnian year. We used the CIRS dataset processed through the up-to-date calibration pipeline to characterize seasonal changes of temperature and abundance profiles in...
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ftdatacite:10.48550/arxiv.1910.12677 2023-05-15T18:23:12+02:00 Seasonal changes in the middle atmosphere of Titan from Cassini/CIRS observations: temperature and trace species abundance profiles from 2004 to 2017 Mathé, Christophe Vinatier, Sandrine Bézard, Bruno Lebonnois, Sébastien Gorius, Nicolas Jennings, Donald E. Mamoutkine, Andrei Guandique, Ever d'Ollone, Jan Vatant 2019 https://dx.doi.org/10.48550/arxiv.1910.12677 https://arxiv.org/abs/1910.12677 unknown arXiv https://dx.doi.org/10.1016/j.icarus.2019.113547 arXiv.org perpetual, non-exclusive license http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Earth and Planetary Astrophysics astro-ph.EP FOS Physical sciences article-journal Article ScholarlyArticle Text 2019 ftdatacite https://doi.org/10.48550/arxiv.1910.12677 https://doi.org/10.1016/j.icarus.2019.113547 2022-03-10T16:27:27Z The Cassini/Composite InfraRed Spectrometer (CIRS) instrument has been observing the middle atmosphere of Titan over almost half a Saturnian year. We used the CIRS dataset processed through the up-to-date calibration pipeline to characterize seasonal changes of temperature and abundance profiles in the middle atmosphere of Titan, from mid-northern winter to early northern summer all around the satellite. We used limb spectra from 590 to 1500 cm$^{-1}$ at 0.5-cm$^{-1}$ spectral resolution, which allows us to probe different altitudes. We averaged the limb spectra recorded during each flyby on a fixed altitude grid to increase the signal-to-noise ratio. These thermal infrared data were analyzed by means of a radiative transfer code coupled with an inversion algorithm, in order to retrieve vertical temperature and abundance profiles. These profiles cover an altitude range of approximately 100 to 600 km, at 10- or 40-km vertical resolution (depending on the observation). Strong changes in temperature and composition occur in both polar regions where a vortex is in place during the winter. At this season, we observe a global enrichment in photochemical compounds in the mesosphere and stratosphere and a hot stratopause located around 0.01 mbar, both linked to downwelling in a pole-to-pole circulation cell. After the northern spring equinox, between December 2009 and April 2010, a stronger enhancement of photochemical compounds occurred at the north pole above the 0.01-mbar region, likely due to combined photochemical and dynamical effects. During the southern autumn in 2015, above the South pole, we also observed a strong enrichment in photochemical compounds that contributed to the cooling of the stratosphere above 0.2 mbar. Close to the northern spring equinox, in December 2009, the thermal profile at 74°N exhibits an oscillation that we interpret in terms of an inertia-gravity wave. Article in Journal/Newspaper South pole DataCite Metadata Store (German National Library of Science and Technology) North Pole South Pole |
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Open Polar |
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DataCite Metadata Store (German National Library of Science and Technology) |
op_collection_id |
ftdatacite |
language |
unknown |
topic |
Earth and Planetary Astrophysics astro-ph.EP FOS Physical sciences |
spellingShingle |
Earth and Planetary Astrophysics astro-ph.EP FOS Physical sciences Mathé, Christophe Vinatier, Sandrine Bézard, Bruno Lebonnois, Sébastien Gorius, Nicolas Jennings, Donald E. Mamoutkine, Andrei Guandique, Ever d'Ollone, Jan Vatant Seasonal changes in the middle atmosphere of Titan from Cassini/CIRS observations: temperature and trace species abundance profiles from 2004 to 2017 |
topic_facet |
Earth and Planetary Astrophysics astro-ph.EP FOS Physical sciences |
description |
The Cassini/Composite InfraRed Spectrometer (CIRS) instrument has been observing the middle atmosphere of Titan over almost half a Saturnian year. We used the CIRS dataset processed through the up-to-date calibration pipeline to characterize seasonal changes of temperature and abundance profiles in the middle atmosphere of Titan, from mid-northern winter to early northern summer all around the satellite. We used limb spectra from 590 to 1500 cm$^{-1}$ at 0.5-cm$^{-1}$ spectral resolution, which allows us to probe different altitudes. We averaged the limb spectra recorded during each flyby on a fixed altitude grid to increase the signal-to-noise ratio. These thermal infrared data were analyzed by means of a radiative transfer code coupled with an inversion algorithm, in order to retrieve vertical temperature and abundance profiles. These profiles cover an altitude range of approximately 100 to 600 km, at 10- or 40-km vertical resolution (depending on the observation). Strong changes in temperature and composition occur in both polar regions where a vortex is in place during the winter. At this season, we observe a global enrichment in photochemical compounds in the mesosphere and stratosphere and a hot stratopause located around 0.01 mbar, both linked to downwelling in a pole-to-pole circulation cell. After the northern spring equinox, between December 2009 and April 2010, a stronger enhancement of photochemical compounds occurred at the north pole above the 0.01-mbar region, likely due to combined photochemical and dynamical effects. During the southern autumn in 2015, above the South pole, we also observed a strong enrichment in photochemical compounds that contributed to the cooling of the stratosphere above 0.2 mbar. Close to the northern spring equinox, in December 2009, the thermal profile at 74°N exhibits an oscillation that we interpret in terms of an inertia-gravity wave. |
format |
Article in Journal/Newspaper |
author |
Mathé, Christophe Vinatier, Sandrine Bézard, Bruno Lebonnois, Sébastien Gorius, Nicolas Jennings, Donald E. Mamoutkine, Andrei Guandique, Ever d'Ollone, Jan Vatant |
author_facet |
Mathé, Christophe Vinatier, Sandrine Bézard, Bruno Lebonnois, Sébastien Gorius, Nicolas Jennings, Donald E. Mamoutkine, Andrei Guandique, Ever d'Ollone, Jan Vatant |
author_sort |
Mathé, Christophe |
title |
Seasonal changes in the middle atmosphere of Titan from Cassini/CIRS observations: temperature and trace species abundance profiles from 2004 to 2017 |
title_short |
Seasonal changes in the middle atmosphere of Titan from Cassini/CIRS observations: temperature and trace species abundance profiles from 2004 to 2017 |
title_full |
Seasonal changes in the middle atmosphere of Titan from Cassini/CIRS observations: temperature and trace species abundance profiles from 2004 to 2017 |
title_fullStr |
Seasonal changes in the middle atmosphere of Titan from Cassini/CIRS observations: temperature and trace species abundance profiles from 2004 to 2017 |
title_full_unstemmed |
Seasonal changes in the middle atmosphere of Titan from Cassini/CIRS observations: temperature and trace species abundance profiles from 2004 to 2017 |
title_sort |
seasonal changes in the middle atmosphere of titan from cassini/cirs observations: temperature and trace species abundance profiles from 2004 to 2017 |
publisher |
arXiv |
publishDate |
2019 |
url |
https://dx.doi.org/10.48550/arxiv.1910.12677 https://arxiv.org/abs/1910.12677 |
geographic |
North Pole South Pole |
geographic_facet |
North Pole South Pole |
genre |
South pole |
genre_facet |
South pole |
op_relation |
https://dx.doi.org/10.1016/j.icarus.2019.113547 |
op_rights |
arXiv.org perpetual, non-exclusive license http://arxiv.org/licenses/nonexclusive-distrib/1.0/ |
op_doi |
https://doi.org/10.48550/arxiv.1910.12677 https://doi.org/10.1016/j.icarus.2019.113547 |
_version_ |
1766202740227178496 |