Abstract : 2G.4
Investigation of the wintertime local-scale meteorology in an Alpine urban area

Massimiliano De Franceschi, Giacomo De Sero, Dino Zardi
University of Trento - Dept. of Civil and Environmental Eng.

In the present work preliminary results from a recent measurement campaign performed during the early Winter season 2006-2007 in the urban area of Trento (Northern Italy) are presented. Aim of the investigation is to deepen the knowledge of the local-scale meteorological processes occurring close to this urban area located within a quite narrow valley in the Alps and accounting for approximately 100000 people. The reason for this interest is the relevance of the weather-factors in determining the pollutant concentrations levels which often exceed the limits set by the Italian and European regulations.

The experimental setup included 4 automated weather stations continuously operated by various Institutions and located close to the city centre, North and South with respect to the urban agglomeration and on the Eastern slope respectively. In addition to this approximately North-South layout (which corresponds to the along-valley direction), 5 air temperature and humidity dataloggers have been placed in the cross-valley direction, including the two opposite slopes and following previous investigations done in the same area. This setup was designed to better integrate the available observing network for a more detailed investigation of the thermal structure also known as Urban Heat Island (UHI).

One further measurement system was installed on a cable car connecting the main urban area to a 400 m higher town on the Western slopes, with the aim of obtaining a more detailed picture (both in space and time) of the vertical temperature structure with special emphasis on the presence and strength of possible inversion layers. After a series of test runs, which demonstrated the reliability of the method, various days of measurements have been performed and the first results are presented here, including the effects of local scale processes (mainly related to the wind field) on the temporal evolution of the temperature field.