利用GPS提取南极Amery冰架海潮信号

潮汐运动是冰架短期垂直运动的来源, 对冰架影响十分显著. 选取2003/2004年度南极夏季期间中国在Amery冰架上连续5 d的GPS数据, 利用GAMIT/GLOBK进行数据处理, 获取了由海潮引起的冰架垂向运动时间序列;垂直方向精度优于0.18 m, 并且和中国南极中山验潮站的潮汐变化曲线进行了对比, 获得了一致的结论. 利用GPS测量海潮可为精化南极地区的海潮模型提供可靠的现场数据, 对南极冰盖物质平衡研究及冰海交互动力学模型研究有着重要的作用.

The Tidal Signals Extracted from GPS Data on the Amery Ice Shelf, Antarctica

Tidal motion is the source of largest short-term vertical motion that an ice shelf experiences, and hence has a significant impact on ice shelves. During the 2003/04 austral summer season, five day's GPS measurement was carried out on the front of the Amery Ice Shelf (AIS), East Antarctica, by the 20~(th) Chinese National Antarctica Research Expedition. The GPS data was processed using GAMIT/GLOBK software with 2-hour static data segment and the vertical precision is less than 0.18 m. To verify the results for the vertical component, the ice shelf GPS tidal signal was compared with the tidal result derived from tide gauge measurements at Zhongshan Station. Comparison of the GPS results with the tide gauge gives a good agreement in amplitude at the few cm level, which indicates that the tide under the front of Amery Ice Shelf is irregular semidiurnal tide, the maximal tidal differences is approximately 2 m. GPS data can be used to validate the ocean tide model around the Antarctic area and such studies are important to improve the knowledge about the Antarctic ice shelf mass balance and dynamical models of ice sheet/ocean interaction.