Seasonal variation of air transport in the Antarctic and Atmospheric Circulation in 1997

• Main Authors: Kazue Suzuki, Takashi Yamanouchi, Naohiko Hirasawa, Tetsuzo Yasunari
• Format: Report
• Language: English
• Published: Department of Polar Science, The Graduate University for Advanced Studies/National Institute of Polar Research/National Institute of Polar Research/Hydrospheric Atmospheric Research Center, Nagoya University 2004
• Subjects: trajectory; Syowa Station; polar vortex; planetary wave; Antarctic; Southern Ocean; The Antarctic; Antarc*; Antarctica; Polar meteorology and glaciology
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=2975; http://id.nii.ac.jp/1291/00002975/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=2975&item_no=1&attribute_id=18&file_no=1

To better understand how present and past climates at Syowa Station, Antarctica relate to climate elsewhere, we analyzed the tropospheric air transport to Syowa Station for the year 1997 using a dataset from the European Centre for Medium Range Weather Forecasts(ECMWF). The five-day trajectories of the air parcels were estimated and analyzed. In the middle troposphere in winter, air parcels were usually from the lower troposphere over the Atlantic. However, in January, most of the air parcels came from latitudes higher than 60°S . The trajectories had little vertical motion and were associated with a low pressure system that forms along the coastal region of Antarctica only in summer. In the lower troposphere, trajectories could be classified as originating in one of three regions: the Southern Ocean, the continental interior, and the east coast. In contrast to the middle troposphere, air parcels from the Southern Ocean had the lowest frequency, irrespective of the time of year. This is partially due to a low pressure system that blocks air parcels from outside the continent. Most trajectories are affected by the drainage flow. An amplified quasi-stationary planetary wave for September to November and a blocking circulation in June make trajectories pass over Antarctica.