Objective mesoscale analysis of daily extreme temperatures in the Po Valley of northern Italy

Abstract

In this paper, an optimum interpolation scheme is applied to produce an objective daily mesoscale analysis of minimum and maximum temperatures in the Emilia Romagna region of northern Italy (essentially the Po Valley). This system is operational at the Regional Meteorological Service. The study of the autocorrelation structures of these fields shows the strong anisotropy induced by the morphological characteristics of the region, and particularly by the Apennines and the Adriatic Sea. To evaluate the structure functions, a data set of the National Hydrological Service has been used. The data, from 1961 to 1977, are available in about 40 stations covering the region fairly uniformly. The analysis scheme is univariate and the structure functions have been evaluated separately for every month of the year.