On the climatology of surface wind direction frequencies for the central Chilean coast

Abstract

A simple climatology giving the annual evolution of monthly mean wind direction frequency along the central Chile coast is presented. An eight-direction wind rose is used. Particular attention is given to the combined monthly mean frequencies of north and northwest (NN) and south and southwest (SS) winds, since these directions have the largest frequencies for most locations. Moreover, these directions are conceptually the most directly related with the climatic scenario used. Simple relationships found between these frequencies and the latitude of the location of maximum monthly mean pressure along the Chilean coast are discussed. These results confirm the validity of the climatic scenario used, which has already been applied in simple empirical climatic models for coastal stations in Chile, such as a monthly mean rainfall frequency model. A quantitative description of NN and SS winds in terms of the location of the maximum monthly mean pressure along the Chilean coast (LMP) allows some estimations of their frequency for locations where no observations are available. Wind direction climatic zones are found to correspond to already known rainfall frequency climatic zones.