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General circulation of the atmosphere
Author(s) -
Arakawa Akio
Publication year - 1975
Publication title -
reviews of geophysics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 8.087
H-Index - 156
eISSN - 1944-9208
pISSN - 8755-1209
DOI - 10.1029/rg013i003p00668
Subject(s) - hadley cell , atmospheric sciences , eddy , troposphere , middle latitudes , latitude , tropopause , circulation (fluid dynamics) , equator , atmospheric circulation , climatology , zonal and meridional , atmosphere (unit) , baroclinity , environmental science , geology , mechanics , meteorology , physics , general circulation model , climate change , turbulence , oceanography , geodesy
Lorenz [1970] presented the commonly accepted view of the general circulation of the atmosphere, which can be summarized as follows: Without surface irregularities and variable heating there can be a mathematically possible steady axially symmetric circulation. Even with surface irregularities there can still be a mathematically possible steady circulation (i.e., one without migratory cyclones or similar transient eddies), but such a circulation would be baroclinically unstable. It is due to this instability that the actual circulation contains fully developed large‐scale migratory eddies. The transient atmospheric eddies receive available potential energy from the axially symmetric component of the circulation and give up some kinetic energy by dissipation. They transport poleward both large amounts of angular momentum across subtropical latitudes near the tropopause level and large amounts of heat across middle latitudes in the lower and the middle troposphere. The result is to induce direct meridional cells in low latitudes (the Hadley circulation) and indirect meridional cells in middle latitudes, which help to maintain the trade winds and the middle‐latitude surface westerlies. The direct meridional cells also carry large amounts of water vapor toward the equator, thus producing the heavy equatorial rainfall. The accompanying release of latent heat supplies additional drive to the low latitude direct cells.