Abstract
Currently, many Extremely Large Telescopes (ELTs: [30 - 100] m size) projects exist. Because of the huge size of such instruments, the selection of an optimal site having a low wind intensity at ground level is a fundamental priority to assure the telescope stability. Wind intensity estimations provided by the general circulation models of the meteorological world centres (such as the ECMWF) are not reliable, because of their low horizontal resolution ( 2^o - 2.5^o). In this paper we test the ability of a non-hydrostatic meso-scale model (Meso-Nh), having a horizontal resolution of 1, in reconstructing the near ground wind intensity (NGW) measured at Paranal, Chile and Maidanak, Uzbekistan, and the ability of the model to discriminate between the two sites. Measurements of the NGW taken during some years at the two sites show a typical wind speed difference of 4 - 5/s. In this paper, NGW measurements from 20 - 25 nights at each site are compared with simulations and a statistic analysis is made. Our conclusion is that the Meso-Nh model can discriminate between the two sites. On the contrary, the analyses and/or forecasts provided by the general circulation models cannot. The limitations of this study are discussed, and some procedures to by-pass these limitations are suggested.
