Submitted to: American Meteorological Society Proceedings
Publication Type: Abstract only
Publication Acceptance Date: 2/2/2014
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: The Optimal Ranking Regime (ORR) method was used to identify intra- to multi-decadal (IMD) time windows containing significant ranking sequences in U.S. climate division temperature data. The simplicity of the ORR procedure’s output – a time series’ most significant non-overlapping periods of high or low rankings – makes it possible to graphically identify common temporal breakpoints and spatial patterns of IMD variability in the analyses of 102 climate division temperature series. This approach is applied to annual AMO and PDO climate indices, a northern hemisphere annual temperature (NHT) series, and divisional annual and seasonal temperature data during 1896-2012. In addition, Pearson correlations are calculated between PDO, AMO, and NHT series and the divisional temperature series. Although PDO phase seems to be an important influence on spring temperatures in the northwest U.S., eastern temperature regimes in annual, winter, summer and fall temperatures are more coincident with cool and warm phase AMO regimes. Annual AMO values also correlate significantly with summer temperatures along the eastern seaboard and fall temperatures in the southwest. Given evidence of the abrupt onset of cold winter temperatures in the eastern U.S. during 1957-1958, the cause and duration of the southeastern U.S. warm hole period - identified here as a cool temperature regime occurring between the late 1950’s and late 1980’s – is discussed.