The claims of unprecedented (but which is not consistent with other sources of climate data) Arctic warming which I reported on last Friday (see) has prompted today’s post. We have published several papers on the areal extent of the coldest temperatures at 5oo hPa within each year over a multi-decadal time period. We also proposed a physical mechanism (i.e. the transit of air masses over open ocean in which cumulus convection resulted in a constraint onthe coldest temperatures to not much colder than -40C). These papers include
Chase, T.N., B. Herman, R.A. Pielke Sr., X. Zeng, and M. Leuthold, 2002: A proposed mechanism for the regulation of minimum midtropospheric temperatures in the Arctic. J. Geophys. Res., 107(D14), 10.10291/2001JD001425
Tsukernik, M., T.N. Chase, M.C. Serreze, R.G. Barry, R. Pielke Sr., B. Herman, and X. Zeng, 2004: On the regulation of minimum mid-tropospheric temperatures in the Arctic. Geophys. Res. Letts., 31, L06112, doi:10.1029/2003GL018831.
Herman, B., M. Barlage, T.N. Chase, and R.A. Pielke Sr., 2008: Update on a proposed mechanism for the regulation of minimum mid-tropospheric and surface temperatures in the Arctic and Antarctic. J. Geophys. Res.-Atmos., 113, D24101, doi:10.1029/2008JD009799.
Ben Herman at The University of Arizona (UA) has introduced a routine update for this climate metric (the temperatures at 500 h Pa with the coldest values highlighted) on the website of the UA Department of Atmospheric Sciences. The Northern and Southern Hemisphere information is accessible from
The use of this climate metric permits the real time tracking of the rate at which the higher latitudes cool off each Fall, warm up in the Spring, as well as the maximum areal extent achieved each year.
Climate Science: Roger Pielke Sr. 