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Atmospheric teleconnections for annual maximum ice cover on the Laurentian Great Lakes
Author(s) -
Assel Raymond,
Rodionov Sergei
Publication year - 1998
Publication title -
international journal of climatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.58
H-Index - 166
eISSN - 1097-0088
pISSN - 0899-8418
DOI - 10.1002/(sici)1097-0088(19980330)18:4<425::aid-joc258>3.0.co;2-q
Subject(s) - teleconnection , climatology , northern hemisphere , geopotential height , atmospheric circulation , anomaly (physics) , quartile , cover (algebra) , geology , ice core , el niño southern oscillation , environmental science , physical geography , geography , precipitation , meteorology , physics , mathematics , mechanical engineering , confidence interval , statistics , condensed matter physics , engineering
Great Lake ice cover records for winters 1963–1990 were used to define anomalously high (low) average ice cover based on the seven highest (seven lowest) annual maximum ice covers. Analysis of the maximum ice cover reveals (i) a low (1964–1976); (ii) a high (1977–1982); and (iii) once again a low (1983–1990) ice cover regime. The high ice cover regime corresponded in part with a hiatus in El Niño–Southern Oscillation (ENSO) events and the beginning of an interdecadal change in Northern Hemisphere atmospheric circulation that started in the late 1970s. About 46% of the lowest quartile ice covers occurred during the mature phase (year+one winter) of El Niño. Only 1 year out of seven with the mature phase of El Niño between 1963 and 1990 was not associated with the lowest quartile ice cover, this was 1977, a pivotal year after which a new climatic regime in the Northern Hemisphere was established. Anomaly maps of 700 hPa geopotential height for the lowest quartile ice cover reveal a zonal flow pattern. Highest quartile ice cover was associated with meridonal circulation from the Arctic directed toward the Great Lakes. Significant differences occur for highest minus lowest quartile ice cover composite 700 hPa height anomaly maps in the Pacific Ocean, the west coast of North America, north Mexico, eastern North America, north central Siberia, western Europe and the adjacent North Atlantic. Correlations between first differences (year t +1 minus year t ) of annual maximum ice cover and 700 hPa geopotential heights for winters 1963–1990 agrees with these teleconnections and were higher than the absolute time series correlations, indicating strong interannual teleconnections. Annual maximum ice cover was also significantly correlated with the tropical Northern Hemisphere teleconnection index. © 1998 Royal Meteorological Society