Acoustic Remote Sensing of Planetary Boundary Layer Dynamics near Ross Island, Antarctica

Abstract

Abstract The blocking effect of Ross Island and Hut Point peninsula, Antarctica, has been investigated since the early part of this century. Due to lack of continuous measurements of boundary-layer winds, the investigations were limited to an overall description of the blocking effect with no information on the diurnal variation or the detailed vertical structure of the approaching airflow. An acoustic sounder (sodar) was deployed during the 1990/91 austral summer season at Williams Field in the upwind area south of Ross Island, Antarctica. Such equipment can continuously measure three-dimensional winds from a few tens of meters above the surface up to an altitude of several hundred meters, thus providing a new opportunity to study the dynamics of the stably stratified planetary boundary layer. In addition to confirming earlier work, the sodar winds show a significant diurnal variation of the blocking effect, which amplifies with height. Such variation is dominated by the changes in the upstream air mass ...