Sea ice characteristics between Middle Weddell Sea and Prydz Bay,Antarctic during the 2003 Australian summer

The Antarctic sea ice was investigated on five occasions between January 4 and February 15,2003.The investigations included the following:(1) estimation of sea ice distribution by ship-based observations between Middle Weddell Sea and Prydz Bay;(2) estimation of sea ice distribution by aerial photography in the Prydz Bay;(3) direct measurements of fast ice thickness and snow cover,as well as ice core sampling in Nella Fjord;(4) estimation of melting sea ice patterns near the ZhongShan Station;and(5) observation of sea ice early freezing near the ZhongShan Station.On average,sea ice covered 14.4% of the studied area.First-year ice was dominant(99.7%~99.8%).Sea ice thickness ranged between 15 cm and 150 cm.The highest sea ice concentration(80%) was observed in Weddell Sea.A large area of open water was observed between 59°56 S and 69°22 S and 040°41 W and 076°23 E.The observed results validate the Silvia model of sea ice drifting.Sea ice distributions in Prydz Bay were more variable due to the complex on-shore topography,the proximity of the Larsemann Hills,and/or the grounded icebergs.The average thickness of landfast ice in Nella Fjord was 169.5 cm.Windblown snow redistribution and the different radiations played an important role in affecting the ice thickness in Nella Fjord.Preliminary freezing of sea ice near the ZhongShan Station conformed to the first two phases of the Pancake Cycle.