Original scientific paper

SEA-SURFACE TEMPERATURE EFFECTS ON 3D BURA FLOW

Lukša Kraljević ; Meteorological and Hydrological Service, Grič 3, 10000 Zagreb, Croatia
Branko Grisogono ; Department of Geophysics, Faculty of Science, Horvatovac bb, 10000 Zagreb, Croatia

Abstract

A nonhydrostatic numerical model with a higher order turbulence closure scheme is used to study the effect of the sea surface temperature (SST) on the nonlinear flow over a mountain in the presence of rotation. The low-level jet that develops on both flanks of the mountain is intensified by the Coriolis effect on the northern flank. Shooting flow develops down the slope ending over the sea while resembling a hydraulic jump. This is considered as bura like flow. Three different cases are addressed, the control run and two cases with the SST 10K colder, and 10K warmer than the control run. The maximum wind speeds that occur are around two times higher than the background wind speeds. Varying the SST induces changes to the flow that affect the position of the hydraulic jump
and the extent and intensity of low-level jets that form on both flanks of the mountain. A hydraulic jump is modulated by orographicaly generated eddies.

Keywords

sea surface temperature; bura; downslope wind; numerical modeling; low-level jet

Hrčak ID:

64562

URI

https://hrcak.srce.hr/64562

Publication date:

15.12.2005.

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