MOSE: a feasibility study for optical turbulence forecast with the Meso-Nh mesoscale model to support AO facilities at ESO sites (Paranal and Armazones)

摘要

We present very encouraging preliminary results obtained in the context ofthe MOSE project, an on-going study aiming at investigating the feasibility ofthe forecast of the optical turbulence and meteorological parameters (in thefree atmosphere as well as in the boundary and surface layer) at Cerro Paranal(site of the Very Large Telescope - VLT) and Cerro Armazones (site of theEuropean Extremely Large Telescope - E-ELT), both in Chile. The study employsthe Meso-Nh atmospheric mesoscale model and aims at supplying a tool foroptical turbulence forecasts to support the scheduling of the scientificprograms and the use of AO facilities at the VLT and the E-ELT. In this studywe take advantage of the huge amount of measurements performed so far atParanal and Armazones by ESO and the TMT consortium in the context of the siteselection for the E-ELT and the TMT to constraint/validate the model. Adetailed analysis of the model performances in reproducing the atmosphericparameters (T, V, p, H, ...) near the ground as well as in the free atmosphere,is critical and fundamental because the optical turbulence depends on most ofthese parameters. This approach permits us to provide an exhaustive andcomplete analysis of the model performances and to better define the modeloperational application. This also helps us to identify the sources ofdiscrepancies with optical turbulence measurements (when they appear) and todiscriminate between different origins of the problem: model parameterization,initial conditions, ... Preliminary results indicate a great accuracy of themodel in reproducing most of the main meteorological parameters in statisticalterms as well as in each individual night in the free atmosphere and inproximity of the surface. The study is co-funded by ESO and INAF-Arcetri(Italy).