Extratropical jet structure : different flow regimes in two-layer QG model /
Numerical experiments were carried out using a two-layer Q G model to investigate sensitivity of the multiple jet flow regime to the thermal forcing, its meridional and storm track structure, and jet transition events. The effect of the thermal relaxation used in many atmospheric models is two-fol...
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| Format: | Thesis Book |
| Language: | English |
| Published: |
[Place of publication not identified] :
[publisher not identified] ;
1997.
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| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=739891771&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | Numerical experiments were carried out using a two-layer Q G model to investigate sensitivity of the multiple jet flow regime to the thermal forcing, its meridional and storm track structure, and jet transition events. The effect of the thermal relaxation used in many atmospheric models is two-fold. It injects energy and damps the flow field. It was found that for different values of the supercriticality of the flow in a two-layer QG model, the net energy generation, the eddy kinetic energy and the heat flux have a maximum in the range of 30-300 days of the thermal damping time. Two different flow regimes were revealed: a turbulent regime with strong upscale energy transfer and a radiatively arrested transfer regime. Results showed that life cycles of the baroclinic waves have a clear pattern in the radiatively arrested transfer regime and become very irregular in the turbulent regime. Storm tracks were investigated in a triple 'et regime. Storm tracks associated with the central jet were centered on a jet axis. The location of the storm track corresponded to the location of the baroclinic wave packets rather than that of Rossby wave breaking. The mechanism of wave packet amplification, which results in an eddy variance maximum, is examined. Experiments showed sharp drops in the heat fluxes and eddy kinetic energy when a new jet evolves in the system. The "quantization" effect (Panetta 1993 results in drops of the energy level and the heat fluxes. The effects of the barotropic shear and wave breaking are also examined. |
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| Item Description: | Vita. "Major Subject: Meteorology". |
| Physical Description: | xv, 120 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilms Inc. |
| Bibliography: | Includes bibliographical references: pages 106-111. |