The Role of Boundary Layer Processes in Limiting PV Homogenization
A β-plane multilevel quasigeostrophic channel model with interactive static stability and a simplified parameterization of atmospheric boundary layer physics is used to study the role of different boundary layer processes in eddy equilibration and their relative effect in maintaining the strong boun...
| Main Authors: | , , |
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| Other Authors: | |
| Format: | Article |
| Language: | en_US |
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American Meteorological Society
2010
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| Online Access: | http://hdl.handle.net/1721.1/52223 |
| _version_ | 1826206488919539712 |
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| author | Zhang, Yang Stone, Peter H. Solomon, Amy |
| author2 | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences |
| author_facet | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Zhang, Yang Stone, Peter H. Solomon, Amy |
| author_sort | Zhang, Yang |
| collection | MIT |
| description | A β-plane multilevel quasigeostrophic channel model with interactive static stability and a simplified parameterization of atmospheric boundary layer physics is used to study the role of different boundary layer processes in eddy equilibration and their relative effect in maintaining the strong boundary layer potential vorticity (PV) gradient.
The model results show that vertical thermal diffusion, along with the surface heat exchange, is primarily responsible for limiting PV homogenization by baroclinic eddies in the boundary layer. Under fixed SST boundary conditions, these two processes act as the source of the mean flow baroclinicity in the lower levels and result in stronger eddy heat fluxes.
Reducing surface friction alone does not result in efficient elimination of the boundary layer PV gradient, but the equilibrium state temperature gradient is still largely influenced by surface friction and its response to changes in surface friction is not monotonic. In the regime of strong surface friction, with reduced poleward eddy heat flux, a strong temperature gradient is still retained. When the surface friction is sufficiently weak along with the stronger zonal wind, the critical level at the center of the jet drops below the surface. As a result, in the lower levels, the eddy heat flux forcing on the mean flow moves away from the center of the jet and the equilibrium state varies only slightly with the strength of the vertical momentum diffusion in the boundary layer. |
| first_indexed | 2024-09-23T13:31:52Z |
| format | Article |
| id | mit-1721.1/52223 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T13:31:52Z |
| publishDate | 2010 |
| publisher | American Meteorological Society |
| record_format | dspace |
| spelling | mit-1721.1/522232022-10-01T15:39:23Z The Role of Boundary Layer Processes in Limiting PV Homogenization Zhang, Yang Stone, Peter H. Solomon, Amy Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Stone, Peter H. Zhang, Yang Stone, Peter H. A β-plane multilevel quasigeostrophic channel model with interactive static stability and a simplified parameterization of atmospheric boundary layer physics is used to study the role of different boundary layer processes in eddy equilibration and their relative effect in maintaining the strong boundary layer potential vorticity (PV) gradient. The model results show that vertical thermal diffusion, along with the surface heat exchange, is primarily responsible for limiting PV homogenization by baroclinic eddies in the boundary layer. Under fixed SST boundary conditions, these two processes act as the source of the mean flow baroclinicity in the lower levels and result in stronger eddy heat fluxes. Reducing surface friction alone does not result in efficient elimination of the boundary layer PV gradient, but the equilibrium state temperature gradient is still largely influenced by surface friction and its response to changes in surface friction is not monotonic. In the regime of strong surface friction, with reduced poleward eddy heat flux, a strong temperature gradient is still retained. When the surface friction is sufficiently weak along with the stronger zonal wind, the critical level at the center of the jet drops below the surface. As a result, in the lower levels, the eddy heat flux forcing on the mean flow moves away from the center of the jet and the equilibrium state varies only slightly with the strength of the vertical momentum diffusion in the boundary layer. Goddard Institute for Space Studies U.S. Department of Energy, Office of Science 2010-03-03T19:50:28Z 2010-03-03T19:50:28Z 2006-06 2008-11 Article http://purl.org/eprint/type/JournalArticle 0022-4928 http://hdl.handle.net/1721.1/52223 Zhang, Yang, Peter H Stone, and Amy Solomon. “The Role of Boundary Layer Processes in Limiting PV Homogenization.” Journal of the Atmospheric Sciences (2009): 1612-1632. © 2009 American Meteorological Society en_US http://dx.doi.org/10.1175/2008jas2914.1 Journal of the Atmospheric Sciences Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf American Meteorological Society American Meteorological Society |
| spellingShingle | Zhang, Yang Stone, Peter H. Solomon, Amy The Role of Boundary Layer Processes in Limiting PV Homogenization |
| title | The Role of Boundary Layer Processes in Limiting PV Homogenization |
| title_full | The Role of Boundary Layer Processes in Limiting PV Homogenization |
| title_fullStr | The Role of Boundary Layer Processes in Limiting PV Homogenization |
| title_full_unstemmed | The Role of Boundary Layer Processes in Limiting PV Homogenization |
| title_short | The Role of Boundary Layer Processes in Limiting PV Homogenization |
| title_sort | role of boundary layer processes in limiting pv homogenization |
| url | http://hdl.handle.net/1721.1/52223 |
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