Hydrodynamic aspects of the Novorossiysk bora episodes in 2012–2013

Abstract

The spatial and time variability of the surface wind field during the bora episodes, including the events of January 27 and February 7, 2012, which were accompanied by windstorms on the coast and Markotkhsky ridge downwind slopes, has been analyzed based on the meteorological parameters observed during the winter expeditions in 2012–2013 to the Novorossiysk—Gelendzhik region. The dependence of the wind velocity on the background atmospheric parameters and incident-flow blocking conditions has been studied for the cases of strong and weak bora. It is assumed that bora is of a wave nature in the considered episodes and the wave drag effect predominated in the observed wind-flow acceleration on a downwind slope. Partial blocking of an incident wind flow by mountains also affects the wind regime in the downwind zone, especially near Gelendzhik, where mountains are higher than in the Novorossiysk region.