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Lagrangian decomposition of the Hadley and Ferrel cells
Author(s) -
Kjellsson J.,
Döös K.
Publication year - 2012
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2012gl052420
Subject(s) - hadley cell , zonal and meridional , isentropic process , eulerian path , atmospheric sciences , lagrangian , atmosphere (unit) , climatology , geology , physics , meteorology , general circulation model , mechanics , climate change , oceanography , mathematical physics
The meridional overturning circulation of the atmosphere between 45°S and 45°N is decomposed using simulated 3D Lagrangian trajectories for calculating the Lagrangian overturning streamfunctions. This permits an analysis of meridional mass transports which otherwise cancel in time‐averaged zonal‐mean Eulerian streamfunctions. Overturning circulations inferred from trajectories of no net meridional transport are qualitatively similar to the Eulerian mean, but yield half the Hadley cell amplitude, and twice that of the Ferrel cell. Cross‐equatorial transports of some 130 Sv result in two cells that account for the remainder of the Hadley cells. The overturning in midlatiudes is partly cancelled by large (>150 Sv) meridional transports approximately following isentropes. Changes and implications for various coordinate systems, e.g., isentropic, are also discussed.