Inhaltszusammenfassung

A large fraction of polar meso-scale cyclogenesis is observed near the sea ice front in both hemispheres during winter. In many cases, development of meso-scale cyclones (MCs) takes place at the low-level baroclinic zone or boundary layer front associated with the sea ice front, and shallow vortices with fronts and low-level jets are generated. This paper investigates polar low developments near the sea ice front, giving examples for both hemispheres and idealized simulations with a meso-scal...A large fraction of polar meso-scale cyclogenesis is observed near the sea ice front in both hemispheres during winter. In many cases, development of meso-scale cyclones (MCs) takes place at the low-level baroclinic zone or boundary layer front associated with the sea ice front, and shallow vortices with fronts and low-level jets are generated. This paper investigates polar low developments near the sea ice front, giving examples for both hemispheres and idealized simulations with a meso-scale model. For two wintertime cases for the Antarctic and the Arctic it can be concluded, that an effective deepening of these low-level baroclinic MCs is combined with upper-level forcing. Idealized numerical simulations with a meso-scale model show that the structure of the sea ice front strongly influences the position and intensity of local MC genesis. The simulated MC developments are associated with the formation of a boundary layer front along the sea ice front. The formation of the vorticity centres is examined by means of the vorticity budget showing the wind field con/divergence to be essential for the production of the modelled vorticity centres.» weiterlesen» einklappen

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DDC Sachgruppe:
Naturwissenschaften