The changing frequency of gales on the swedish west coast and its possible relation to the increased damage to coniferous forests of Southern Sweden

Abstract

This paper deals with the frequency of gales on the Swedish west coast over a period of 130 years. The results show that gale frequency was very high in the 1870s and in the 1920s. During the period 1940–1960, relatively few gales were recorded. From about 1970 and onward, the frequency has again risen to very high levels in the late 1980s.The changing frequency of gales is discussed in connection with the increased damage to coniferous forests observed in southern Sweden over the last two decades. To find possible explanations for the fluctuations in the wind climate, the wind data series were compared with other climatic data and solar radiation variations. Correlation tests and harmonic analyses of the time series investigated indicate the existence of a relationship between seasonal fluctuations of gale frequency, air pressure, air temperature, temperature of surface waters of the sea to the west of Sweden, and solar radiation.