THE CONFLUENCE ZONE OF THE INTENSE KATABATIC WINDS AT TERRA-NOVA BAY, ANTARCTICA, AS DERIVED FROM AIRBORNE SASTRUGI SURVEYS AND MESOSCALE NUMERICAL MODELING

Airborne surveys of wind-induced features on the snow surface have been used to construct the time-averaged winter surface airflow pattern. The surface motion field has also been simulated by a mesoscale primitive equation model using terrain slopes with a horizontal resolution of 32 km. Both methods of analysis demonstrate that the intense katabatic airstream at Terra Nova Bay is forced by converging air currents in the continental interior. The broadscale confluence zone becomes organized into two regions within about 180 km of the coast. The primary route for katabatic mass transport into the Terra Nova Bay area is Reeves Glacier valley, but an important secondary source is provided by airflow down David Glacier. The former is generated by the Coriolis-induced concentration of mass transport on the left side (looking downwind) of the broadscale confluence zone as well as by the near-coastal mountain deflection of airflow into the valley head. -from Authors