Fine-scale wavelike structure of the surface-based turbulent layer at Dome C, Antarctica

During January-November 2012, observations were carried out at the French-Italian station of Concordia (Dome C, Antarctica) to study the behaviour of atmospheric turbulence in the atmospheric boundary layer (ABL). The behaviour of thermal turbulence was observed remotely using a specially developed high-resolution sodar. In contrast to the previous observations, the turbulence pattern in the ABL was observed by sodar beginning from ?2 m and with vertical resolution <2 m. Sodar observations were accompanied by in-situ measurements of the mean and turbulent atmospheric characteristics. Thank to high-resolution sodar measurements, it was found that within the Surface-based Turbulent Layer (STL), a distinct wave activity occurs very often. Mainly, the form of wavelike fine-scale turbulent layers is classified as "braid" (or "herringbones") pattern. They can be associated with internal gravity-shear waves attributed to the Kelvin-Helmholtz instability. Some characteristics (spatial and temporal scales, vertical extension) of the wavelike structures are determined and presented.