Leaky Rigid Lid: New Dissipative Modes in the Troposphere
An effective boundary condition is derived for the top of the troposphere, based on a wave radiation condition at the tropopause. This boundary condition, which can be formulated as a pseudodifferential equation, leads to new vertical dissipative modes. These modes can be computed explicitly in the...
| Main Authors: | , , |
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| Other Authors: | |
| Format: | Article |
| Language: | English |
| Published: |
American Meteorological Society,
2014-06-16T13:35:15Z.
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| Subjects: | |
| Online Access: | Get fulltext |
| Summary: | An effective boundary condition is derived for the top of the troposphere, based on a wave radiation condition at the tropopause. This boundary condition, which can be formulated as a pseudodifferential equation, leads to new vertical dissipative modes. These modes can be computed explicitly in the classical setup of a hydrostatic, nonrotating atmosphere with a piecewise constant Brunt-Vaisala frequency. In the limit of an infinitely strongly stratified stratosphere, these modes lose their dissipative nature and become the regular baroclinic tropospheric modes under the rigid-lid approximation. For realistic values of the stratification, the decay time scales of the first few modes for mesoscale disturbances range from an hour to a week, suggesting that the time scale for some atmospheric phenomena may be set up by the rate of energy loss through upward-propagating waves. National Science Foundation (U.S.) (Grant NSF 0903008) National Science Foundation (U.S.) (Grant DMS 1007967) National Science Foundation (U.S.) (Grant DMS 0907955) National Science Foundation (U.S.) (Grant DMS 1115278) |
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