Modelling of large-scale structures arising under developed turbulent convection in a horizontal fluid layer (with application to the problem of tropical cyclone origination)
| Autor: | Se. E. Startsev, G. V. Levina, S. S. Mioseev, M. V. Starkov, V. D. Zimin |
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| Přispěvatelé: | EGU, Publication, Institute of Continuous Media Mechanics of the RAS (ICMM), Ural Branch of Russian Academy of Sciences (UB RAS), Space Research Institute of the Russian Academy of Sciences (IKI), Russian Academy of Sciences [Moscow] (RAS) |
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Convection
[SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph] Meteorology [SDU.STU]Sciences of the Universe [physics]/Earth Sciences Stratification (water) Perturbation (astronomy) Mechanics [SDU.ASTR] Sciences of the Universe [physics]/Astrophysics [astro-ph] Instability Vortex [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO] [PHYS.ASTR.CO] Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO] [SDU.STU] Sciences of the Universe [physics]/Earth Sciences Compressibility Tropical cyclone Internal heating Geology |
| Zdroj: | Scopus-Elsevier Nonlinear Processes in Geophysics Nonlinear Processes in Geophysics, European Geosciences Union (EGU), 2000, 7 (1/2), pp.49-58 |
| ISSN: | 1607-7946 1023-5809 |
| Popis: | The work is concerned with the results of theoretical and laboratory modelling the processes of the large-scale structure generation under turbulent convection in the rotating-plane horizontal layer of an incompressible fluid with unstable stratification. The theoretical model describes three alternative ways of creating unstable stratification: a layer heating from below, a volumetric heating of a fluid with internal heat sources and combination of both factors. The analysis of the model equations show that under conditions of high intensity of the small-scale convection and low level of heat loss through the horizontal layer boundaries a long wave instability may arise. The condition for the existence of an instability and criterion identifying the threshold of its initiation have been determined. The principle of action of the discovered instability mechanism has been described. Theoretical predictions have been verified by a series of experiments on a laboratory model. The horizontal dimensions of the experimentally-obtained long-lived vortices are 4÷6 times larger than the thickness of the fluid layer. This work presents a description of the laboratory setup and experimental procedure. From the geophysical viewpoint the examined mechanism of the long wave instability is supposed to be adequate to allow a description of the initial step in the evolution of such large-scale vortices as tropical cyclones - a transition form the small-scale cumulus clouds to the state of the atmosphere involving cloud clusters (the stage of initial tropical perturbation). |
| Databáze: | OpenAIRE |
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