Mesoscale Optical Turbulence simulations at Dome C

Abstract

These last years ground-based astronomy has been looking towards Antarctica, especially its summits and the internal continental plateau where the optical turbulence (OT) appears to be confined in a shallow layer close to the surface. Preliminary measurements have so far indicated pretty good value for the seeing above 30-35 m: 0.36" (Agabi et al. 2006), 0.27" (Lawrence et al. 2004) and 0.3" (Trinquet et al. 2008) at Dome C. Site testing campaigns are however extremely expensive, instruments provide only local measurements and atmospheric modeling might represent a step ahead towards the search and selection of astronomical sites thanks to the possibility to reconstruct 3D Cn2 maps over a surface of several kilometers. The Antarctic Plateau represents therefore an important benchmark test to evaluate the possibility to discriminate sites on the same plateau. Our group (Hagelin et al. 2008) has proven that the analyses from the ECMWF global model do not describe with the required accuracy the antarctic boundary and surface layers in the plateau. A better description could be obtained with a mesoscale model. The Meso-Nh model has proven to be reliable in reproducing 3D maps of OT above mid-latitude astronomical sites (Masciadri et al. 1999ab, 2004, Masciadri and Jabouille 2005). In this paper we study the ability of the Meso-Nh model in reconstructing the meteorological parameters as well as the OT above Dome C with different model configurations. We concentrate our attention on the model abilities in reproducing the OT surface layer thickness Hsl and the integral of the Cn2 in the free atmosphere and in the surface layer. It is worth to highlight that these are the first estimates ever done so far with a mesoscale model of the optical turbulence above the internal Antarctic Plateau.

13 pages, 8 figures, accepted for publication in MNRAS

References in corpus (2)

• Comparison of the atmosphere above the South Pole, Dome C and Dome A: first attempt
• Meteorologic parameters analysis above Dome C made with ECMWF data

Cited by in corpus (13)

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• Optical turbulence forecast: ready for an operational application
• Astronomy in Antarctica
• MOSE: optical turbulence and atmospherical parameters operational forecast at ESO ground-based sites. II: atmospherical parameters in the surface layer [0-30] m
• Monitoring the optical turbulence in the surface layer at Dome C, Antarctica, with sonic anemometers
• Optical turbulence simulations at Mt Graham using the Meso-NH mode
• Mesoscale optical turbulence simulations at Dome C: refinements
• Forecasting surface layer atmospheric parameters at the LBT site
• Optical turbulence vertical distribution with standard and high resolution at Mt. Graham
• Forecasts of the atmospherical parameters close to the ground at the LBT site in the context of the ALTA project
• A dedicated tool for a full 3D Cn2 investigation
• MOSE: zooming on the Meso-NH mesoscale model performances at the surface layer at ESO sites (Paranal and Armazones)
• Analysis of the planetary boundary layer with a database of large-eddy simulation experiments