Forecast of surface layer meteorological parameters at Cerro Paranal with a mesoscale atmospherical model

Abstract

In this paper, we aim to prove the feasibility of the forecast of all the most relevant classical atmospherical parameters for astronomical applications (wind speed, wind direction, temperature) above the European Southern Observatory ground-based site of Cerro Paranal using a mesoscale atmospherical model called MESO-NH. In an earlier paper, we preliminarily treated the model performances obtained in reconstructing some key atmospherical parameters in the surface layer 0-30 m, studying the bias and the root-mean-square error (RMSE) on a statistical sample of 20 nights. The results were very encouraging and therefore it appeared mandatory to confirm such good results on a much richer statistical sample. In this paper, the study has been extended to a total sample of 129 nights between 2007 and 2011, distributed in different parts of the solar year. This large sample made our analysis more robust and definitive in terms of the model performances and permitted us to confirm the excellent performances of the model. Besides, we present an independent analysis of the model performances using the method of the contingency tables. Such a method permitted us to provide complementary key information with respect to the bias and the RMSE, which is particularly useful for an operational implementation of a forecast system.