基于GRACE资料研究南极冰盖消减对海平面的影响

The sea level change from the Antarctic ice sheet based on GRACE

利用5年的GRACE重力数据,计算了南极1°×1°等效水量时间序列,得到每个格网的趋势项,结果表明在西南极Amundsen区域有明显的负增长,超过-80 mm/a,南极半岛存在着负增长,东南极Enderby Land地区质量增长;计算得到2002年7月到2007年9月南极、东南极和西南极冰盖的等效体积变化分别为-78±37 km^3/a,-3±46 km^3/a和-75±50 km^3/a,对应海平面变化的贡献为0.21±0.1 mm/a,0.008±0.127 mm/a和0.2±0.14 mm/a.该结果与国际最新研究结果一致.同时发现冰后回弹是影响利用GRACE研究南极冰盖质量变化的关键因素.

The Antarctic equivalent water height time series and the inter-annual trend on a 1°×1° grid are inferred. Amundsen Sea Embayment in West Antarctic shows apparent negative rates, exceeding -80 mm/a, while Antarctic Peninsula with smaller negative rate and Enderby Land in East Antarctic with positive one. The 5-year equivalent water volume variation trends, in Antarctica, East Antarctica and West Antarctica, are -78±37 km3/a,-3±46 km3/a and -75±50 km3/a, and the corresponding contribution to sea level change are 0.21±0.1 mm/a, 0.008±0.127 mm/a and 0.2±0.14 mm/a, respectively, from July 2002 to September 2007. The results are in accord with recent results from Ramillien （2006） and Velicogna （2006）. The PGR （Post Glacial Rebound） model is still the key factor to the study of the Antarctic ice sheet with GRACE.