Bracketing Northern Hemisphere mid-tropospheric temperatures: Relation to circulation Indices

Wednesday, 17 December 2014
Thomas N Chase1, Benjamin M Herman2, Roger A Pielke Sr Sr1 and Joel Armstrong1, (1)University of Colorado at Boulder, Boulder, CO, United States, (2)University of Arizona, Tucson, AZ, United States
We discuss the extent to which atmospheric-oceanic linkages limits minimum 500 hPa temperatures at high latitudes to -42C and maximum 500 mb temperatures to -5C, which are seen in tropical regions (i.e. mid-tropospheric temperatures are bracketed between -42 and -5C). The magnitude of both the minimum and maximum temperatures appear to be convectively controlled. The areal extent of both minimum and maximum temperatures vary quasi-periodically though are not in phase. We physically explain the relation between large-scale circulation patterns and the bracketing of Northern Hemisphere mid-tropospheric temperatures.