History of the long series of daily air temperature in Padova (1725-1998)

Abstract

The history of the origin of the study of meteorology in Padova and its connection to the major developments of this science in Italy and the international context are presented. Special topics are: the scientific legacy of Galileo Galilei and the Accademia del Cimento, the birth of the first meteorological networks, i.e., Ferdinand II and Leopold de' Medici who created the Rete Medicea, J. Jurin and the network of the Royal Society, London, L. Cotte and the Société Royale de Médicine, Paris, J. J. Hemmer and the Societas Meteorologica Palatina, Mannheim. After outlining the cultural background that favoured the development of meteorology, emphasis is given to the plurisecular time series of meteorological observations, taken in Padova since 1725, in its national and international context. This long series includes barometric pressure, air temperature, wind direction and speed; state of the sky and occurrence of meteorological events and precipitation. Special reference is made to indoor and outdoor temperature observations. Solar radiation falling on each exposure has been modelled in order to know when data were fully reliable and when they were less so. A vertical profile of air temperature has allowed corrections of the change of instrument level, when necessary. In terms of homogeneity, the series can be divided into several periods, during which instruments and operational methods, position, general criteria were unchanged: origins in homes of the first observers (1725-1767); the First Period at the Specola (1768-1812); the Second Period at the Specola (1813-1864); the Third and Fourth Periods at the Specola (1865-1937); the Last Measurements at the Specola (1938-1962); the Giovanni Magrini Observatory of the Water Magistrate (1920-today); the Gino Allegri Airport (1926-1990), the Botanical Gardens (1980-today), the CNR (1984-1986; 1993-today). The latest period, with the birth of new weather stations, is the most affected by anthropic effect. The simultaneous presence of an urban and a rural weather station pointed out local effects which dominate the urban heat island.