A global blended tropopause based on ERA data, Part II: trends and tropical broadening
A new tropopause definition involving a flow-dependent blending of the traditional thermal tropopause with one based on potential vorticity has been developed and applied to the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalyses (ERA), ERA-40 and ERA-Interim. Global and regional tre...
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Online Access: | https://centaur.reading.ac.uk/25587/ https://centaur.reading.ac.uk/25587/1/910_ftp.pdf https://centaur.reading.ac.uk/25587/3/Wilcox_part2_centaur.pdf |
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ftunivreading:oai:centaur.reading.ac.uk:25587 2024-05-12T07:54:56+00:00 A global blended tropopause based on ERA data, Part II: trends and tropical broadening Wilcox, Laura Hoskins, Brian Shine, Keith 2012-04 text https://centaur.reading.ac.uk/25587/ https://centaur.reading.ac.uk/25587/1/910_ftp.pdf https://centaur.reading.ac.uk/25587/3/Wilcox_part2_centaur.pdf en eng Royal Meteorological Society https://centaur.reading.ac.uk/25587/1/910_ftp.pdf https://centaur.reading.ac.uk/25587/3/Wilcox_part2_centaur.pdf Wilcox, L. <https://centaur.reading.ac.uk/view/creators/90004004.html> orcid:0000-0001-5691-1493 , Hoskins, B. <https://centaur.reading.ac.uk/view/creators/90000043.html> and Shine, K. <https://centaur.reading.ac.uk/view/creators/90000340.html> orcid:0000-0003-2672-9978 (2012) A global blended tropopause based on ERA data, Part II: trends and tropical broadening. Quarterly Journal of the Royal Meteorological Society, 138 (664). pp. 576-584. ISSN 1477-870X doi: https://doi.org/10.1002/qj.910 <https://doi.org/10.1002/qj.910> Article PeerReviewed 2012 ftunivreading https://doi.org/10.1002/qj.910 2024-04-17T14:43:05Z A new tropopause definition involving a flow-dependent blending of the traditional thermal tropopause with one based on potential vorticity has been developed and applied to the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalyses (ERA), ERA-40 and ERA-Interim. Global and regional trends in tropopause characteristics for annual and solsticial seasonal means are presented here, with emphasis on significant results for the newer ERA-Interim data for 1989-2007. The global-mean tropopause is rising at a rate of 47 m decade−1 , with pressure falling at 1.0 hPa decade−1 , and temperature falling at 0.18 K decade−1 . The Antarctic tropopause shows decreasing heights,warming,and increasing westerly winds. The Arctic tropopause also shows a warming, but with decreasing westerly winds. In the tropics the trends are small, but at the latitudes of the sub-tropical jets they are almost double the global values. It is found that these changes are mainly concentrated in the eastern hemisphere. Previous and new metrics for the rate of broadening of the tropics, based on both height and wind, give trends in the range 0.9◦ decade−1 to 2.2◦ decade−1 . For ERA-40 the global height and pressure trends for the period 1979-2001 are similar: 39 m decade−1 and -0.8 hPa decade−1. These values are smaller than those found from the thermal tropopause definition with this data set, as was used in most previous studies. Article in Journal/Newspaper Antarc* Antarctic Arctic CentAUR: Central Archive at the University of Reading Arctic Antarctic The Antarctic Quarterly Journal of the Royal Meteorological Society 138 664 576 584 |
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Open Polar |
collection |
CentAUR: Central Archive at the University of Reading |
op_collection_id |
ftunivreading |
language |
English |
description |
A new tropopause definition involving a flow-dependent blending of the traditional thermal tropopause with one based on potential vorticity has been developed and applied to the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalyses (ERA), ERA-40 and ERA-Interim. Global and regional trends in tropopause characteristics for annual and solsticial seasonal means are presented here, with emphasis on significant results for the newer ERA-Interim data for 1989-2007. The global-mean tropopause is rising at a rate of 47 m decade−1 , with pressure falling at 1.0 hPa decade−1 , and temperature falling at 0.18 K decade−1 . The Antarctic tropopause shows decreasing heights,warming,and increasing westerly winds. The Arctic tropopause also shows a warming, but with decreasing westerly winds. In the tropics the trends are small, but at the latitudes of the sub-tropical jets they are almost double the global values. It is found that these changes are mainly concentrated in the eastern hemisphere. Previous and new metrics for the rate of broadening of the tropics, based on both height and wind, give trends in the range 0.9◦ decade−1 to 2.2◦ decade−1 . For ERA-40 the global height and pressure trends for the period 1979-2001 are similar: 39 m decade−1 and -0.8 hPa decade−1. These values are smaller than those found from the thermal tropopause definition with this data set, as was used in most previous studies. |
format |
Article in Journal/Newspaper |
author |
Wilcox, Laura Hoskins, Brian Shine, Keith |
spellingShingle |
Wilcox, Laura Hoskins, Brian Shine, Keith A global blended tropopause based on ERA data, Part II: trends and tropical broadening |
author_facet |
Wilcox, Laura Hoskins, Brian Shine, Keith |
author_sort |
Wilcox, Laura |
title |
A global blended tropopause based on ERA data, Part II: trends and tropical broadening |
title_short |
A global blended tropopause based on ERA data, Part II: trends and tropical broadening |
title_full |
A global blended tropopause based on ERA data, Part II: trends and tropical broadening |
title_fullStr |
A global blended tropopause based on ERA data, Part II: trends and tropical broadening |
title_full_unstemmed |
A global blended tropopause based on ERA data, Part II: trends and tropical broadening |
title_sort |
global blended tropopause based on era data, part ii: trends and tropical broadening |
publisher |
Royal Meteorological Society |
publishDate |
2012 |
url |
https://centaur.reading.ac.uk/25587/ https://centaur.reading.ac.uk/25587/1/910_ftp.pdf https://centaur.reading.ac.uk/25587/3/Wilcox_part2_centaur.pdf |
geographic |
Arctic Antarctic The Antarctic |
geographic_facet |
Arctic Antarctic The Antarctic |
genre |
Antarc* Antarctic Arctic |
genre_facet |
Antarc* Antarctic Arctic |
op_relation |
https://centaur.reading.ac.uk/25587/1/910_ftp.pdf https://centaur.reading.ac.uk/25587/3/Wilcox_part2_centaur.pdf Wilcox, L. <https://centaur.reading.ac.uk/view/creators/90004004.html> orcid:0000-0001-5691-1493 , Hoskins, B. <https://centaur.reading.ac.uk/view/creators/90000043.html> and Shine, K. <https://centaur.reading.ac.uk/view/creators/90000340.html> orcid:0000-0003-2672-9978 (2012) A global blended tropopause based on ERA data, Part II: trends and tropical broadening. Quarterly Journal of the Royal Meteorological Society, 138 (664). pp. 576-584. ISSN 1477-870X doi: https://doi.org/10.1002/qj.910 <https://doi.org/10.1002/qj.910> |
op_doi |
https://doi.org/10.1002/qj.910 |
container_title |
Quarterly Journal of the Royal Meteorological Society |
container_volume |
138 |
container_issue |
664 |
container_start_page |
576 |
op_container_end_page |
584 |
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1798853628123938816 |