Analysis of cold spells in the Greek region

Abstract

The extreme phenomenon of cold-spell events in the Greek region was investigated in this study by using a combined deterministic-stochastic model, along with 31 yr daily minimum temperature data from 16 meteorological stations of the Hellenic National Meteorological Service (HNMS). Trend analysis and the spatio-temporal distribution of cold spells were investigated by applying linear regression and Fourier analysis. The frequency, duration, distribution, timing and intensity of cold spells were successfully fitted with Poisson, Gauss and exponential distributions. The features of cold spells were found to vary widely, due to the effect of physicogeographical parameters such as latitude, longitude, altitude, and continentality, as well as to the synoptic weather situations prevailing in the various Greek sub-areas. The relative importance of the physicogeographical peculiarities was assessed: latitude and altitude were evaluated as the most important parameters for determining the features of cold spells in Greece. The highest probability of cold spells in the Greek peninsula exists when a persistent NW European and/or Siberian anticyclone reaches its highest intensity during winter and extends high-pressure ridges to the Balkans, and particularly to the Greek area. © Inter-Research 2004.