Sampling the ground layer of the atmosphere at Dome C using fast sonic-anemometers

The ground layer turbulence at Dome C is the cause for more than 90% of the total turbulence column. While the height of this layer has been currently measured to be approximately 30m, no long term statistics is available from this part of the atmosphere. In order to plan the construction of future telescope at this site temperature site, temperature, wind speed and turbulence measurements are also necessary. Using fast sonicanemometers we present, a preliminary set of data covering January to October 2007 sampling these quantities at heights of 8, 16 and 28 meters.