Isentropic zonal average formalism and the near-surface circulation
Hoskins (1991) proposed dividing the atmosphere into 3 regions: Overworld, Middleworld and Underworld, using potential temperature θ and potential vorticity (PV) as reference (Fig. 1). In the Underworld (θ < 300 K), isentropes intercept the Earth’s surface and a direct isentropic zonal aver...
| Main Authors: | , |
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| Other Authors: | |
| Format: | Conference Paper |
| Language: | English |
| Published: |
2014
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| Subjects: | |
| Online Access: | https://hdl.handle.net/10356/79719 http://hdl.handle.net/10220/20355 |
| _version_ | 1811696516165795840 |
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| author | Koh, Tieh Yong Plumb, Alan R. |
| author2 | Proceedings of the Conference on Atmospheric and Oceanic Fluid Dynamics, American Meteorological Society (14th : 2003) |
| author_facet | Proceedings of the Conference on Atmospheric and Oceanic Fluid Dynamics, American Meteorological Society (14th : 2003) Koh, Tieh Yong Plumb, Alan R. |
| author_sort | Koh, Tieh Yong |
| collection | NTU |
| description | Hoskins (1991) proposed dividing the
atmosphere into 3 regions: Overworld,
Middleworld and Underworld, using potential
temperature θ and potential vorticity (PV) as
reference (Fig. 1). In the Underworld (θ < 300
K), isentropes intercept the Earth’s surface
and a direct isentropic zonal average
circulation exists in the mid-latitudes. Held and
Schneider (1999) suggested that this
circulation may be understood as follows: the
equator-pole temperature gradient determines
the near-surface eddy heat flux via an eddydiffusion
mechanism. The poleward eddy heat
flux in turn drives an equatorward mean flow
next to the surface whose horizontal
convergence in the subtropics forces the mean
quasi-isentropic ascent of air into the
troposphere. Radiative cooling causes air to
sink back to the surface, thus closing the
circulation. |
| first_indexed | 2024-10-01T07:40:36Z |
| format | Conference Paper |
| id | ntu-10356/79719 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T07:40:36Z |
| publishDate | 2014 |
| record_format | dspace |
| spelling | ntu-10356/797192020-09-26T21:24:19Z Isentropic zonal average formalism and the near-surface circulation Koh, Tieh Yong Plumb, Alan R. Proceedings of the Conference on Atmospheric and Oceanic Fluid Dynamics, American Meteorological Society (14th : 2003) DRNTU::Science::Astronomy Hoskins (1991) proposed dividing the atmosphere into 3 regions: Overworld, Middleworld and Underworld, using potential temperature θ and potential vorticity (PV) as reference (Fig. 1). In the Underworld (θ < 300 K), isentropes intercept the Earth’s surface and a direct isentropic zonal average circulation exists in the mid-latitudes. Held and Schneider (1999) suggested that this circulation may be understood as follows: the equator-pole temperature gradient determines the near-surface eddy heat flux via an eddydiffusion mechanism. The poleward eddy heat flux in turn drives an equatorward mean flow next to the surface whose horizontal convergence in the subtropics forces the mean quasi-isentropic ascent of air into the troposphere. Radiative cooling causes air to sink back to the surface, thus closing the circulation. Accepted version 2014-08-21T01:36:26Z 2019-12-06T13:32:42Z 2014-08-21T01:36:26Z 2019-12-06T13:32:42Z 2003 2003 Conference Paper Koh, T. Y. & Plumb, R. A. (2003). Isentropic zonal average formalism and the near-surface circulation. Proceedings of the 14th Conference on Atmospheric and Oceanic Fluid Dynamics, American Meteorological Society, 9-13 June 2003. https://hdl.handle.net/10356/79719 http://hdl.handle.net/10220/20355 en © 2003 The Author(s). This is the author created version of a work that has been peer reviewed and accepted for publication by Proceedings of the 14th Conference on Atmospheric and Oceanic Fluid Dynamics, American Meteorological Society, 9-13 June 2003. It incorporates referee’s comments but changes resulting from the publishing process, such as copyediting, structural formatting, may not be reflected in this document. application/pdf |
| spellingShingle | DRNTU::Science::Astronomy Koh, Tieh Yong Plumb, Alan R. Isentropic zonal average formalism and the near-surface circulation |
| title | Isentropic zonal average formalism and the near-surface circulation |
| title_full | Isentropic zonal average formalism and the near-surface circulation |
| title_fullStr | Isentropic zonal average formalism and the near-surface circulation |
| title_full_unstemmed | Isentropic zonal average formalism and the near-surface circulation |
| title_short | Isentropic zonal average formalism and the near-surface circulation |
| title_sort | isentropic zonal average formalism and the near surface circulation |
| topic | DRNTU::Science::Astronomy |
| url | https://hdl.handle.net/10356/79719 http://hdl.handle.net/10220/20355 |
| work_keys_str_mv | AT kohtiehyong isentropiczonalaverageformalismandthenearsurfacecirculation AT plumbalanr isentropiczonalaverageformalismandthenearsurfacecirculation |