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Baroclinic adjustment in a zonally varying flow
Author(s) -
Mole Nils,
James Ian N.
Publication year - 1990
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.49711649202
Subject(s) - baroclinity , extratropical cyclone , forcing (mathematics) , eddy , climatology , northern hemisphere , atmospheric sciences , environmental science , atmosphere (unit) , heat flux , zonal flow (plasma) , geology , meteorology , mechanics , physics , heat transfer , turbulence , plasma , quantum mechanics , tokamak
Abstract In agreement with previous published results, based on a 2‐layer model measure of baroclinicity, the extratropical northern hemisphere zonal mean atmosphere is found to be close to marginal stability in both winter and summer of the FGGE year. In winter, however, considerable zonal variations are present. Results of some numerical model runs, with both zonally symmetric and varying thermal forcing, are presented, and it is found that for sufficiently short forcing time scales a state close to marginal stability, and a storm‐tracklike region, can be produced. Large steady eddies do not seem to result so readily from the thermal forcing. Time‐lagged correlations provide evidence of forcing of the high frequency (periods less than 10 days) eddy heat flux by the baroclinicity, and it is suggested that the low frequency eddy heat flux may be a result of a nonlinear cascade from the baroclinic scales.