Isentropic primitive equations for the moist troposphere
Despite the knowledge that the potential temperature of an air parcel has a dependence on its water vapour content, potential temperature is often still calculated as if the parcel were dry, assuming that this moisture dependence is negligible. We show that such a dry potential temperature approxima...
| Main Authors: | , |
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| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
| Published: |
2014
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| Online Access: | https://hdl.handle.net/10356/103655 http://hdl.handle.net/10220/19294 |
| _version_ | 1811692488852766720 |
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| author | Lee, Shao-Yi Koh, Tieh-Yong |
| author2 | School of Physical and Mathematical Sciences |
| author_facet | School of Physical and Mathematical Sciences Lee, Shao-Yi Koh, Tieh-Yong |
| author_sort | Lee, Shao-Yi |
| collection | NTU |
| description | Despite the knowledge that the potential temperature of an air parcel has a dependence on its water vapour content, potential temperature is often still calculated as if the parcel were dry, assuming that this moisture dependence is negligible. We show that such a dry potential temperature approximation is not suitable for tropical regions. Moisture gradient terms are seen in the isentropic primitive equations when Exner and Montgomery functions are generalised with moist specific heat capacities, forming a contribution to the horizontal momentum tendency comparable to that by the Montgomery function. This reflects how local horizontal gradients in potential temperature created by inhomogeneous water vapour distribution are relatively significant compared to gradients created by inhomogeneous temperature, in a large-scale background of weak horizontal temperature gradient. In such an environment, water plays an active role in tropical atmospheric dynamics without the uptake or release of latent heat during phase changes. Hence, we suggest that the tropical troposphere is a place where the atmosphere can behave dynamically as a binary-component fluid at local and regional scales. |
| first_indexed | 2024-10-01T06:36:35Z |
| format | Journal Article |
| id | ntu-10356/103655 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T06:36:35Z |
| publishDate | 2014 |
| record_format | dspace |
| spelling | ntu-10356/1036552020-03-07T12:45:26Z Isentropic primitive equations for the moist troposphere Lee, Shao-Yi Koh, Tieh-Yong School of Physical and Mathematical Sciences Earth Observatory of Singapore DRNTU::Science::Physics::Meteorology and climatology Despite the knowledge that the potential temperature of an air parcel has a dependence on its water vapour content, potential temperature is often still calculated as if the parcel were dry, assuming that this moisture dependence is negligible. We show that such a dry potential temperature approximation is not suitable for tropical regions. Moisture gradient terms are seen in the isentropic primitive equations when Exner and Montgomery functions are generalised with moist specific heat capacities, forming a contribution to the horizontal momentum tendency comparable to that by the Montgomery function. This reflects how local horizontal gradients in potential temperature created by inhomogeneous water vapour distribution are relatively significant compared to gradients created by inhomogeneous temperature, in a large-scale background of weak horizontal temperature gradient. In such an environment, water plays an active role in tropical atmospheric dynamics without the uptake or release of latent heat during phase changes. Hence, we suggest that the tropical troposphere is a place where the atmosphere can behave dynamically as a binary-component fluid at local and regional scales. 2014-05-02T08:56:22Z 2019-12-06T21:17:09Z 2014-05-02T08:56:22Z 2019-12-06T21:17:09Z 2013 2013 Journal Article Lee, S. Y., & Koh, T. Y. (2014). Isentropic primitive equations for the moist troposphere. Quarterly Journal of the Royal Meteorological Society, in press. 0035-9009 https://hdl.handle.net/10356/103655 http://hdl.handle.net/10220/19294 10.1002/qj.2312 en Quarterly journal of the royal meteorological society © 2013 Royal Meteorological Society. 7 p. |
| spellingShingle | DRNTU::Science::Physics::Meteorology and climatology Lee, Shao-Yi Koh, Tieh-Yong Isentropic primitive equations for the moist troposphere |
| title | Isentropic primitive equations for the moist troposphere |
| title_full | Isentropic primitive equations for the moist troposphere |
| title_fullStr | Isentropic primitive equations for the moist troposphere |
| title_full_unstemmed | Isentropic primitive equations for the moist troposphere |
| title_short | Isentropic primitive equations for the moist troposphere |
| title_sort | isentropic primitive equations for the moist troposphere |
| topic | DRNTU::Science::Physics::Meteorology and climatology |
| url | https://hdl.handle.net/10356/103655 http://hdl.handle.net/10220/19294 |
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