Optical turbulence: site selection above the internal Antarctic plateau with a mesoscale model

TL;DR

This study uses mesoscale modeling to evaluate and compare optical turbulence at key Antarctic sites, aiding optimal site selection for astronomy by providing reliable turbulence profiles and site-specific characteristics.

Contribution

The paper demonstrates the successful validation of the Meso-Nh model for Antarctic sites and provides the first homogeneous turbulence estimates across Dome C, South Pole, and Dome A.

Findings

Meso-Nh model accurately reconstructs turbulence parameters at Dome C.

Different sites exhibit distinct turbulence and surface layer characteristics.

First homogeneous estimates of optical turbulence above 20-22 km for multiple Antarctic sites.

Abstract

Atmospherical mesoscale models can offer unique potentialities to characterize and discriminate potential astronomical sites. Our team has recently completely validated the Meso-Nh model above Dome C (Lascaux et al. 2009, 2010). Using all the measurements of CN2 profiles (15 nights) performed so far at Dome C during the winter time (Trinquet et al. 2008) we proved that the model can reconstruct, on rich statistical samples, reliable values of all the three most important parameters characterizing the turbulence features of an antarctic site: the surface layer thickness, the seeing in the free atmosphere and in the surface layer. Using the same Meso-Nh model configuration validated above Dome C, an extended study is now on-going for other sites above the antarctic plateau, more precisely South Pole and Dome A. In this contribution we present the most important results obtained in the model validation process and the results obtained in the comparison between different astronomical sites above the internal plateau. The Meso-Nh model confirms its ability in discriminating between different optical turbulence behaviors, and there is evidence that the three sites have different characteristics regarding the seeing and the surface layer thickness. We highlight that this study provides the first homogeneous estimate, done with comparable statistics, of the optical turbulence developed in the whole 20-22 km above the ground at Dome C, South Pole and Dome A.