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Seasonal and regional 300 hpa heights, 300–1000 hpa thicknesses and associated 300 hPa zonal flow changes in the northern hemisphere between 1976 and 1990
Author(s) -
Weber Gerd Rainer
Publication year - 1994
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/joc.3370140705
Subject(s) - latitude , climatology , subtropics , troposphere , zonal flow (plasma) , northern hemisphere , atmospheric sciences , middle latitudes , tropics , environmental science , southern hemisphere , geology , plasma , physics , geodesy , quantum mechanics , fishery , tokamak , biology
Using monthly 300 hPa height and 300–1000 hPa thickness data published by the synoptic climatology group of the Free University of Berlin, height and associated zonal flow changes were analysed for the period 1976 through to 1990. The 300 hPa heights rose most notably in the tropics, somewhat less in the lower mid‐latitudes, and they were lower in high latitudes. Via the height gradient, an increase in the zonal flow at 300 hPa can be derived for the subtropics and in upper mid‐latitudes. Using correlation analysis, relationships between tropospheric thickness anomalies in the lower latitudes—where the bulk of the most recent tropospheric warming has occurred—and changes in the 300 hPa height field elsewhere are explored. It is found that warm (cold) anomalies in the tropical troposphere are related to 300 hPa gradient increases (decreases) in the subtropics, but to gradient decreases (increases) in mid‐latitudes. Gradient increases in the mid‐latitudes moreover are generally related more closely to high‐latitude cool anomalies than to lower mid‐latitude warm anomalies or low‐latitude cool anomalies.