Inhaltszusammenfassung

Development mechanisms of Antarctic mesocyclones in the Weddell Sea area are examined by means of simulations with a mesoscale model using different idealized initial conditions. In one of the experiments, a mesocyclone develops over an area of open water close to the coast of the Antarctic continent. The forcing mechanisms of this mesocyclogenesis are investigated by means of sensitivity studies in which certain physical processes and the relevance of the surface conditions topography, sea s...Development mechanisms of Antarctic mesocyclones in the Weddell Sea area are examined by means of simulations with a mesoscale model using different idealized initial conditions. In one of the experiments, a mesocyclone develops over an area of open water close to the coast of the Antarctic continent. The forcing mechanisms of this mesocyclogenesis are investigated by means of sensitivity studies in which certain physical processes and the relevance of the surface conditions topography, sea surface temperature and ice coverage are examined. The sensitivity experiments show the simulated mesocyclone is forced by a complex interaction of several forcing mechanisms at different stages of the development rather than by a single mechanism. The topography of the eastern Weddell Sea region and the summertime coastal polynia close to the coast are shown to be of great importance for the mesocyclogenesis. A synoptic low located north of the eastern coast can support the katabatic flow over the sloped ice sheet, enhance the generation of cyclonic vorticity due to vertical stretching and lead to a transport of cold air over the coastal polynia. The diabatic process of the convergence of the sensible and latent heat fluxes in the boundary layer can then become the dominant forcing mechanism for the further development stage of the mesocyclogenesis.» weiterlesen» einklappen

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DDC Sachgruppe:
Naturwissenschaften