Classification of typical meteorological days from global irradiation records and comparison between two Mediterranean coastal sites in Corsica Island

In a view to make easier the use of meterological data as the input of ener gy systems simulations, this study proposes a methodology to reduce a long time series, of several variables into some typical meteorological days, ch aracterizing classes with their frequency distributions and transition prob abilities. To do it, we have defined parameters elaborated from hourly clea rness index profiles computed from hourly horizontal and inclined irradiati on recorded at two nearest Mediterranean coastal sites in Corsica Island. T he classification used the aggregation Ward's method, and the results are c onfirmed by discriminant analyses. Two studies based on different time step s (monthly and annual) have been investigated. The classes are more compact , and the variances of the meteorological and mathematical variables in a g iven class remain quite low by comparison with the mean. We show in the fir st part (monthly time step) that the recorded days are clustered in 3, 4 or 5 groups and in the second part (annual time-step on about 4 years of irra diation data), 3 typical meteorological days classes allows to characterize the irradiation profiles of both locations. (C) 2000 Elsevier Science Ltd. All rights reserved.