Department of Atmospheric Sciences – University of Illinois
3:00 pm: Conversation and Cookies in Room 109 ASB
3:30 pm: Seminar in Room 144 Loomis Lab
Changes in extreme temperatures and pressures in the Arctic have received little attention in the context of climate change. Here we examine the distributions and extremes of surface air temperature, pressure, and precipitation in the Arctic for the late 20th century using Alaskan station data, an atmospheric reanalysis, and general circulation models (GCMs). There is good agreement among these sources for the late 20th century, with broader distributions for both temperature and pressure in winter as compared to summer, and over land as compared to over ocean. The output from 21st-century greenhouse simulations by the GCMs is then used to address the occurrence of extremes in the coming decades. The model projections of the 21st-century extremes largely agree with changes in the mean state, with record low temperatures decreasing in frequency and record high temperatures increasing in frequency. The changes in 21st-century extremes are more pronounced over the ocean where the present-day distributions are narrower. The projected decreases of mean pressure result in more frequent occurrences of extreme low pressure, especially over the Arctic Ocean. Mean precipitation increases are consistent with increased daily precipitation in all seasons.
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