Interpretation of recent Southern Hemisphere climate change

David W. J. Thompson, Susan Solomon

Research output: Contribution to journalArticlepeer-review

Abstract

Climate variability in the high-latitude Southern Hemisphere (SH) is dominated by the SH annular mode, a large-scale pattern of variability characterized by fluctuations in the strength of the circumpolar vortex. We present evidence that recent trends in the SH tropospheric circulation can be interpreted as a bias toward the high-index polarity of this pattern, with stronger westerly flow encircling the polar cap. It is argued that the largest and most significant tropospheric trends can be traced to recent trends in the lower stratospheric polar vortex, which are due largely to photochemical ozone losses. During the summer-fall season, the trend toward stronger circumpolar flow has contributed substantially to the observed warming over the Antarctic Peninsula and Patagonia and to the cooling over eastern Antarctica and the Antarctic plateau.
Original languageEnglish
Pages (from-to)895-899
Number of pages5
JournalScience
Volume296
Issue number5569
DOIs
Publication statusPublished - 3 May 2002

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