Characterising Saturn's vertical temperature structure from Cassini/CIRS
Thermal infrared spectra of Saturn from 10-1400 cm(-1) at 15 cm(-1) spectral resolution and a spatial resolution of 1 degrees-2 degrees latitude have been obtained by the Cassini Composite Infrared Spectrometer [Flasar, F.M., and 44 colleagues, 2004. Space Sci. Rev. 115, 169-297]. Many thousands of...
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2007
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Online Access: | https://hdl.handle.net/1983/249108b0-5d5e-4a4c-be28-a548a77bd055 https://research-information.bris.ac.uk/en/publications/249108b0-5d5e-4a4c-be28-a548a77bd055 https://doi.org/10.1016/j.icarus.2007.02.006 |
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ftubristolcris:oai:research-information.bris.ac.uk:publications/249108b0-5d5e-4a4c-be28-a548a77bd055 2024-01-28T10:07:59+01:00 Characterising Saturn's vertical temperature structure from Cassini/CIRS Fletcher, L. N. Irwin, P. G. J. Teanby, N. A. Orton, G. S. Parrish, P. D. de Kok, R. Howett, C. Calcutt, S. B. Bowles, N. Taylor, F. W. 2007-08 https://hdl.handle.net/1983/249108b0-5d5e-4a4c-be28-a548a77bd055 https://research-information.bris.ac.uk/en/publications/249108b0-5d5e-4a4c-be28-a548a77bd055 https://doi.org/10.1016/j.icarus.2007.02.006 eng eng info:eu-repo/semantics/restrictedAccess Fletcher , L N , Irwin , P G J , Teanby , N A , Orton , G S , Parrish , P D , de Kok , R , Howett , C , Calcutt , S B , Bowles , N & Taylor , F W 2007 , ' Characterising Saturn's vertical temperature structure from Cassini/CIRS ' , Icarus , vol. 189 , no. 2 , pp. 457-478 . https://doi.org/10.1016/j.icarus.2007.02.006 CLOUD STRUCTURE HUBBLE-SPACE-TELESCOPE structure EQUATORIAL REGION VOYAGER INFRARED MEASUREMENTS ROTOTRANSLATIONAL ABSORPTION-SPECTRA PARA-HYDROGEN FRACTION UPPER TROPOSPHERE OUTER PLANETS Saturn HELIUM ABUNDANCE THERMAL STRUCTURE atmospheres composition article 2007 ftubristolcris https://doi.org/10.1016/j.icarus.2007.02.006 2024-01-04T23:39:09Z Thermal infrared spectra of Saturn from 10-1400 cm(-1) at 15 cm(-1) spectral resolution and a spatial resolution of 1 degrees-2 degrees latitude have been obtained by the Cassini Composite Infrared Spectrometer [Flasar, F.M., and 44 colleagues, 2004. Space Sci. Rev. 115, 169-297]. Many thousands of spectra, acquired over eighteen-months of observations, are analysed using an optimal estimation retrieval code [Irwin, P.G.J., Parrish, P., Fouchet, T., Calcutt, S.B., Taylor, F.W., Simon-Miller, A.A., Nixon, C.A., 2004. Icarus 172, 37-49] to retrieve the temperature structure and para-hydrogen distribution over Saturn's northern (winter) and Southern (summer) hemispheres. The vertical temperature structure is analysed in detail to study seasonal asymmetries in the tropopause height (65-90 mbar), the location of the radiative-comective boundary (350-500 mbar), and the variation with latitude of a temperature knee (between 150 and 300 mbar) which was first observed in inversions of Voyager/IRIS spectra [Hanel, R., and 15 colleagues, 1981. Science 212, 192-200; Hanel, R., Conrath, B., Flasar, F.M., Kunde, V., Maguire, W., Pearl, J.C., Pirraglia, J., Samuelson, R., Cruikshank, D.P., Gautier, D., Gierasch, P.J., Horn, L., Ponnamperuma, C., 1982. Science 215, 544-548]. Uncertainties due to both the modelling of spectral absorptions (collision-induced absorption coefficients, tropospheric hazes, helium abundance) and the nature of our retrieval algorithm are quantified. Temperatures in the stratosphere near 1 mbar show a 25-30 K temperature difference between the north pole and south pole. This asymmetry becomes less pronounced with depth as the radiative time constant for the atmospheric response increases at deeper pressure levels. Hemispherically-symmetric small-scale temperature structures associated with zonal winds are superimposed onto the temperature asymmetry for pressures greater than 100 mbar. The para-hydro.-en fraction in the 100-400 mbar range is greater than equilibrium predictions for the southern ... Article in Journal/Newspaper North Pole South pole University of Bristol: Bristol Research Hubble ENVELOPE(158.317,158.317,-80.867,-80.867) Maguire ENVELOPE(66.917,66.917,-74.017,-74.017) North Pole South Pole Icarus 189 2 457 478 |
institution |
Open Polar |
collection |
University of Bristol: Bristol Research |
op_collection_id |
ftubristolcris |
language |
English |
topic |
CLOUD STRUCTURE HUBBLE-SPACE-TELESCOPE structure EQUATORIAL REGION VOYAGER INFRARED MEASUREMENTS ROTOTRANSLATIONAL ABSORPTION-SPECTRA PARA-HYDROGEN FRACTION UPPER TROPOSPHERE OUTER PLANETS Saturn HELIUM ABUNDANCE THERMAL STRUCTURE atmospheres composition |
spellingShingle |
CLOUD STRUCTURE HUBBLE-SPACE-TELESCOPE structure EQUATORIAL REGION VOYAGER INFRARED MEASUREMENTS ROTOTRANSLATIONAL ABSORPTION-SPECTRA PARA-HYDROGEN FRACTION UPPER TROPOSPHERE OUTER PLANETS Saturn HELIUM ABUNDANCE THERMAL STRUCTURE atmospheres composition Fletcher, L. N. Irwin, P. G. J. Teanby, N. A. Orton, G. S. Parrish, P. D. de Kok, R. Howett, C. Calcutt, S. B. Bowles, N. Taylor, F. W. Characterising Saturn's vertical temperature structure from Cassini/CIRS |
topic_facet |
CLOUD STRUCTURE HUBBLE-SPACE-TELESCOPE structure EQUATORIAL REGION VOYAGER INFRARED MEASUREMENTS ROTOTRANSLATIONAL ABSORPTION-SPECTRA PARA-HYDROGEN FRACTION UPPER TROPOSPHERE OUTER PLANETS Saturn HELIUM ABUNDANCE THERMAL STRUCTURE atmospheres composition |
description |
Thermal infrared spectra of Saturn from 10-1400 cm(-1) at 15 cm(-1) spectral resolution and a spatial resolution of 1 degrees-2 degrees latitude have been obtained by the Cassini Composite Infrared Spectrometer [Flasar, F.M., and 44 colleagues, 2004. Space Sci. Rev. 115, 169-297]. Many thousands of spectra, acquired over eighteen-months of observations, are analysed using an optimal estimation retrieval code [Irwin, P.G.J., Parrish, P., Fouchet, T., Calcutt, S.B., Taylor, F.W., Simon-Miller, A.A., Nixon, C.A., 2004. Icarus 172, 37-49] to retrieve the temperature structure and para-hydrogen distribution over Saturn's northern (winter) and Southern (summer) hemispheres. The vertical temperature structure is analysed in detail to study seasonal asymmetries in the tropopause height (65-90 mbar), the location of the radiative-comective boundary (350-500 mbar), and the variation with latitude of a temperature knee (between 150 and 300 mbar) which was first observed in inversions of Voyager/IRIS spectra [Hanel, R., and 15 colleagues, 1981. Science 212, 192-200; Hanel, R., Conrath, B., Flasar, F.M., Kunde, V., Maguire, W., Pearl, J.C., Pirraglia, J., Samuelson, R., Cruikshank, D.P., Gautier, D., Gierasch, P.J., Horn, L., Ponnamperuma, C., 1982. Science 215, 544-548]. Uncertainties due to both the modelling of spectral absorptions (collision-induced absorption coefficients, tropospheric hazes, helium abundance) and the nature of our retrieval algorithm are quantified. Temperatures in the stratosphere near 1 mbar show a 25-30 K temperature difference between the north pole and south pole. This asymmetry becomes less pronounced with depth as the radiative time constant for the atmospheric response increases at deeper pressure levels. Hemispherically-symmetric small-scale temperature structures associated with zonal winds are superimposed onto the temperature asymmetry for pressures greater than 100 mbar. The para-hydro.-en fraction in the 100-400 mbar range is greater than equilibrium predictions for the southern ... |
format |
Article in Journal/Newspaper |
author |
Fletcher, L. N. Irwin, P. G. J. Teanby, N. A. Orton, G. S. Parrish, P. D. de Kok, R. Howett, C. Calcutt, S. B. Bowles, N. Taylor, F. W. |
author_facet |
Fletcher, L. N. Irwin, P. G. J. Teanby, N. A. Orton, G. S. Parrish, P. D. de Kok, R. Howett, C. Calcutt, S. B. Bowles, N. Taylor, F. W. |
author_sort |
Fletcher, L. N. |
title |
Characterising Saturn's vertical temperature structure from Cassini/CIRS |
title_short |
Characterising Saturn's vertical temperature structure from Cassini/CIRS |
title_full |
Characterising Saturn's vertical temperature structure from Cassini/CIRS |
title_fullStr |
Characterising Saturn's vertical temperature structure from Cassini/CIRS |
title_full_unstemmed |
Characterising Saturn's vertical temperature structure from Cassini/CIRS |
title_sort |
characterising saturn's vertical temperature structure from cassini/cirs |
publishDate |
2007 |
url |
https://hdl.handle.net/1983/249108b0-5d5e-4a4c-be28-a548a77bd055 https://research-information.bris.ac.uk/en/publications/249108b0-5d5e-4a4c-be28-a548a77bd055 https://doi.org/10.1016/j.icarus.2007.02.006 |
long_lat |
ENVELOPE(158.317,158.317,-80.867,-80.867) ENVELOPE(66.917,66.917,-74.017,-74.017) |
geographic |
Hubble Maguire North Pole South Pole |
geographic_facet |
Hubble Maguire North Pole South Pole |
genre |
North Pole South pole |
genre_facet |
North Pole South pole |
op_source |
Fletcher , L N , Irwin , P G J , Teanby , N A , Orton , G S , Parrish , P D , de Kok , R , Howett , C , Calcutt , S B , Bowles , N & Taylor , F W 2007 , ' Characterising Saturn's vertical temperature structure from Cassini/CIRS ' , Icarus , vol. 189 , no. 2 , pp. 457-478 . https://doi.org/10.1016/j.icarus.2007.02.006 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1016/j.icarus.2007.02.006 |
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