Publication Date:
2022-05-25
Description:
Author Posting. © American Meteorological Society, 2008. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of the Atmospheric Sciences 65 (2008): 3316–3326, doi:10.1175/2008JAS2579.1.
Description:
The connection between transport barriers and potential vorticity (PV) barriers in PV-conserving flows is investigated with a focus on zonal jets in planetary atmospheres. A perturbed PV staircase model is used to illustrate important concepts. This flow consists of a sequence of narrow eastward and broad westward zonal jets with a staircase PV structure; the PV steps are at the latitudes of the cores of the eastward jets. Numerically simulated solutions to the quasigeostrophic PV conservation equation in a perturbed PV staircase flow are presented. These simulations reveal that both eastward and westward zonal jets serve as robust meridional transport barriers. The surprise is that westward jets, across which the background PV gradient vanishes, serve as robust transport barriers. A theoretical explanation of the underlying barrier mechanism is provided. It is argued that transport barriers near the cores of westward zonal jets, across which the background PV gradient is small, are found in Jupiter’s midlatitude weather layer and in the earth’s summer hemisphere subtropical stratosphere.
Description:
Support for this work was provided
by the U.S. National Science Foundation under
Grants CMG0417425 and OCE0648284.
Keywords:
Jets
;
Planetary atmospheres
;
Potential vorticity
;
Stratosphere
;
Vorticity
Repository Name:
Woods Hole Open Access Server
Type:
Article
Format:
application/pdf
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