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Temperature, humidity and cloud near fronts in the middle and upper troposphere
Author(s) -
Sawyer J. S.
Publication year - 1958
Publication title -
quarterly journal of the royal meteorological society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.744
H-Index - 143
eISSN - 1477-870X
pISSN - 0035-9009
DOI - 10.1002/qj.49708436206
Subject(s) - troposphere , subsidence , jet stream , frontogenesis , jet (fluid) , warm front , humidity , geology , atmospheric sciences , cold front , temperature gradient , front (military) , environmental science , isentropic process , potential temperature , meteorology , climatology , mechanics , geomorphology , physics , oceanography , mesoscale meteorology , structural basin
Exploratory flights through fronts beneath the jet stream confirm that a narrow frontal zone some 30 to 50 mi wide with sharp boundaries is often present at the 500 mb level. On other occasions the temperature changes are more diffuse. The air in and near the frontal zone is usually very dry and must have undergone subsidence. Dynamic considerations suggest that the very strong temperature gradient of the frontal zone at 500 mb arises from the differential subsidence of air on the cold side of the jet stream which leads to a tilting of the isentropic surfaces.