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dc.contributor.authorScreen, James A.
dc.contributor.authorSimmonds, Ian
dc.date.accessioned2013-06-13T15:10:26Z
dc.date.issued2012-08-25
dc.description.abstractThis study provides a comprehensive analysis of observed 50-year (1961–2010) seasonal air temperature trends from radiosonde ascents above Antarctica. Comparisons between multiple radiosonde data sets (homogenized in different ways) at each of eight Antarctic stations reveals substantial differences in the upper-air temperature trend magnitudes and their statistical significance between data sets. However, when considering the average of these data sets at each station, or averaging across all stations, a robust vertical profile of half-century temperature change emerges, characterized by mid-tropospheric warming and stratospheric cooling. Statistically significant Multistation-mean 500 hPa warming (0.1 to 0.2°C decade−1) is found in all seasons, whereas the lower stratospheric cooling has been manifest primarily in austral spring and summer, but with larger magnitudes (−1.0 to −2.0°C decade−1). We undertake the first spatial reconstructions of pan-Antarctic upper-air temperature trends. They strongly suggest that both the year-round mid-tropospheric warming and spring and summer lower stratospheric cooling have occurred above the entire continent, although their magnitudes and significance vary regionally. The reconstructed 500 hPa warming trends in winter and spring are largest over West Antarctica, the Ross Ice shelf, Victoria Land and Oates Land, and show close resemblance to those found in previously published surface temperature trend reconstructions, suggesting coupling between the surface and trends aloft. We speculate that the winter and spring mid-tropospheric warming may, in part, be driven by tropical ocean warming, analogous to proposed mechanisms for the co-located surface warming. The spring and summer lower stratospheric cooling is entirely consistent with the temperature response to ozone depletion.en_GB
dc.identifier.citationVol. 117 (D16), article D16108en_GB
dc.identifier.doi10.1029/2012JD017885
dc.identifier.urihttp://hdl.handle.net/10871/10642
dc.language.isoenen_GB
dc.publisherAmerican Geophysical Unionen_GB
dc.subjectAntarcticaen_GB
dc.subjectclimate changeen_GB
dc.subjectradiosondeen_GB
dc.subjectstratosphereen_GB
dc.subjecttemperatureen_GB
dc.subjecttroposphereen_GB
dc.titleHalf-century air temperature change above Antarctica: Observed trends and spatial reconstructionsen_GB
dc.typeArticleen_GB
dc.date.available2013-06-13T15:10:26Z
dc.descriptionCopyright © 2012 American Geophysical Unionen_GB
dc.identifier.eissn2169-8961
dc.identifier.journalJournal of Geophysical Research D: Atmospheresen_GB


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