Baroclinic Multiple Zonal Jets on the SphereSource: Journal of the Atmospheric Sciences:;2005:;Volume( 062 ):;issue: 007::page 2484Author:Lee, Sukyoung
DOI: 10.1175/JAS3481.1Publisher: American Meteorological Society
Abstract: Multiple zonal jets are investigated with a two-level primitive equation model on the sphere in which both baroclinicity and planetary radius are varied. As in the case for a two-layer quasigeostrophic model on a ?-plane channel, it is found both that the Rhines scale successfully predicts the meridional scale of the multiple zonal jets, and that these jets are maintained in part by an eddy momentum flux divergence associated with slow baroclinic waves at the interjet minimum. A scaling analysis suggests that njets? (a/?m)1/2, with the constraints ?e ≡ 8 sin2f (?m/?? ) > 1 and njets ≥ 1, where njets is the number of the jets, a the planetary radius, ?m one-half of the pole-to-equator potential temperature difference, ?e the supercriticality of the two-layer Phillips model, ?? the potential temperature difference between the two levels, and ? the latitude. The number of jets simulated by the model agrees with this scaling, provided that Ljet ≤ a, where Ljet is the jet scale. In model runs with a large planet where multiple zonal jets exist, the time?mean eddy heat flux is found to be consistent with the diffusive picture of Held and Larichev. In contrast, for the model runs with the planetary size equal to that of Earth, baroclinic adjustment is found to be more relevant. These results are consistent with the finding that in the large-planet (Earth-like) model runs, the jet/eddy scale is smaller than (comparable to) the corresponding planetary radius.
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contributor author | Lee, Sukyoung | |
date accessioned | 2017-06-09T16:52:18Z | |
date available | 2017-06-09T16:52:18Z | |
date copyright | 2005/07/01 | |
date issued | 2005 | |
identifier issn | 0022-4928 | |
identifier other | ams-75668.pdf | |
identifier uri | http://onlinelibrary.yabesh.ir/handle/yetl/4218029 | |
description abstract | Multiple zonal jets are investigated with a two-level primitive equation model on the sphere in which both baroclinicity and planetary radius are varied. As in the case for a two-layer quasigeostrophic model on a ?-plane channel, it is found both that the Rhines scale successfully predicts the meridional scale of the multiple zonal jets, and that these jets are maintained in part by an eddy momentum flux divergence associated with slow baroclinic waves at the interjet minimum. A scaling analysis suggests that njets? (a/?m)1/2, with the constraints ?e ≡ 8 sin2f (?m/?? ) > 1 and njets ≥ 1, where njets is the number of the jets, a the planetary radius, ?m one-half of the pole-to-equator potential temperature difference, ?e the supercriticality of the two-layer Phillips model, ?? the potential temperature difference between the two levels, and ? the latitude. The number of jets simulated by the model agrees with this scaling, provided that Ljet ≤ a, where Ljet is the jet scale. In model runs with a large planet where multiple zonal jets exist, the time?mean eddy heat flux is found to be consistent with the diffusive picture of Held and Larichev. In contrast, for the model runs with the planetary size equal to that of Earth, baroclinic adjustment is found to be more relevant. These results are consistent with the finding that in the large-planet (Earth-like) model runs, the jet/eddy scale is smaller than (comparable to) the corresponding planetary radius. | |
publisher | American Meteorological Society | |
title | Baroclinic Multiple Zonal Jets on the Sphere | |
type | Journal Paper | |
journal volume | 62 | |
journal issue | 7 | |
journal title | Journal of the Atmospheric Sciences | |
identifier doi | 10.1175/JAS3481.1 | |
journal fristpage | 2484 | |
journal lastpage | 2498 | |
tree | Journal of the Atmospheric Sciences:;2005:;Volume( 062 ):;issue: 007 | |
contenttype | Fulltext |