Abstract
A local strong northwesterly wind prevails near Rausu on the Shiretoko Peninsula, Hokkaido, during winter. This local wind is known as Rausu-dashi and is restricted to the leeside of the peninsula. The Rausu-dashi sometimes causes accidents, at sea off the coast of Rausu. The purpose of the present study is to investigate characteristics of the strong wind using the meteorological data around the peninsula. The meteorological data include routine surface meteorological observations at AMeDAS observatories and the Hokkaido Development Bureau's observatories, and radiosonde observations at the Nemuro observatory.
The main results and discussion are summarized as follows:
1) The Rausu-dashi, a strong northwesterly wind, prevails especially in winter.
2) Seasonal features of the wind on the Nemuro Strait side are different from those on the Sea of Okhotsk side.
3) The wind speed at the Rausu AMeDAS observatory on the leeside of the saddle of the peninsula is larger than that at the Shibetsu AMeDAS observatory.
4) There is a close relationship between the wind speed at the Rausu AMeDASS observatory and that at the pass of the peninsula.
5) The radiosonde data show that inversion layers often appear between 700 and 900 hPa in the Rausu-dashi. There is a possibility that the Rausu-dashi may be caused by a hydraulic jump when the northwesterly strong winds pass the peninsula.
