Quality and performance of a PM10 daily forecasting model

Particularly in the cold season unfavorable dissemination conditions of the ambient air lead to higher-than-average PM10 concentrations in parts of the western Alpe-Adria-Region, covering the provinces South Tyrol, Carinthia and Styria. Therefore, EU pollution standards cannot be met in the cold season and partial traffic regulation measures are taken in Bolzano, Klagenfurt and Graz, the three capitals in this region. Decision making for these regulations may be based on the average PM 10 concentration of the next day provided that reliable forecasts of these values can be offered. In the present paper we show how multiple linear regression models combining information of the present day with meteorological forecasts of the next day can help forecasting daily PM 10 concentrations for sites located in the three cities. Special emphasis is given to an appropriate selection of the regressor variables readily available as measured values, factors or meteorological forecasts suitable in operational mode. To reflect the quality of the forecast properly, we define a quality function where prediction errors near the threshold PM10 of 50 mu g m(-3) are assumed to be more severe than errors in regions that are either far below or above the threshold. Since December 2004, the forecasts are used as a monitoring and information tool in Graz. Our daily forecasts have been carried out in cooperation with the meteorologists from the ZAMG Styria (Styrian meteorological office). The investigations in terms of the quality function and according possible decision rules show that our prediction models may support future decisions concerning possible traffic restrictions not only in Graz, but also in Bolzano and Klagenfurt. (c) 2007 Elsevier Ltd. All rights reserved.