卫星重力用于南极冰盖物质消融评估

ANTARCTIC ICE MASS LOSS FROM GRAVITY SATELLITE

2002年3月发射的GRACE重力卫星,以前所未有的精度和分辨率给出了重力场的时空变化。Jason1重复观测获得海平面的变化,GRACE估计海水质量重新分布引起的海面高变化,两者之差获得比容海面高变化,将该结果与WOA05结果作季节性比较,结果表明CSRRL04,GFZRL04和GRGSGL04三者结果与WOA05结果吻合,优于其他GRACE系列数据。将选取的CSRRL04,GFZRL04和GRGSGL04用于南极冰盖质量变化研究,得到南极冰盖冰雪物质变化的空间分布,结果表明西南极Amundsen区域明显地负增长,南极半岛存在着负增长。估算2003年1月—2007年12月南极冰盖冰雪消融的等效体积变化,变化区间为-76km3/a——69km3/a,对应海平面的贡献变化区间为0.17mm/a—0.21mm/a。

GRACE, launched in March 2003, measures spatio-temporal variations of the gravity field with an unprecedented resolution and precision. Jasonl measures the combined effect of steric and mass variations, while the former part can be inferred from GRACE and the latter from WOA05. The seasonal steric variations from difference between Jasonl and GRACE are com- pared with that of WOA05. The results show that CSR RL04, GFZ RL04 , GRGS GL04 agree well with WOA05. Antarctic mass change rate distributions are estimated from the three chosen GRACE data sets. Amundsen Sea Embayment in West Antarctic shows apparent negative rates, and Antarctic Peninsula with smaller negative rate. Antarctic ice volume loss rates is （ -69± 36）km3/a, while the corresponding contributions to sea level change is （0.19 ±0.1 ） mm/a, from Janauary 2003 to December 2007. Key words GRACE, Jasonl, WOA05, steric sea level, Antarctic ice loss.