利用卫星重力探测南极冰盖质量变化

Variations of antarctic ice-sheet mass measured by satellite gravity

针对不同GIA模型在南极地区的改正差异较大,分析了采用不同GIA模型分析得到的南极冰盖融化误差值,研究了南极冰盖质量变化加速度。研究结果表明,扣除IJ05模型影响后,整个南极冰盖质量以(-81.5±4.2)Gt/a的速度和(-12.3±6.5)Gt/a2的加速度融化,对海平面上升贡献分别为(0.23±0.01)mm/a和(0.03±0.02)mm/a2。西南极处于加速融化状态,速度由2003—2008年间的-37.7Gt/a增加至2009—2013年的-156.0Gt/a。东南极冰盖在2009年前处于稳定,2009年后逐渐积累,且积累速度不断增加。2003-2013期间内东南极,西南极冰盖质量变化速度及加速度分别为(28±13.4)Gt/a、(9.8±2.8)Gt/a2、-(108.1±3.5)Gt/a和-(21.1±2.9)Gt/a2,南极冰盖融化主要来自西南极。南极冰盖周年变化影响较强,每年10月左右其质量变化振幅达到最大,半周年变化影响最大在西南极,S2潮波振幅在Ronne冰架附近较大,振幅最大值达到25mm。

According to the big differences among different GIA models in Antarctic area, the paper u- ses different GIA models to compute ice-sheet melting error and analyzes Antarctic ice-sheet mass variation acceleration. The results show that the GIA correction has crucial impact to Antarctic ice-sheet mass varia- tions. The Antarctic ice-sheet melting rate and acceleration are （-81.5±4.2） Gt/a and （-12.3±6.5） G1/a2 after deduction of the GIA correction and contributes （0.23±0.01） mm/a and（ 0. 03±0.02） mm/a2 to the global sea-level rise. The melting state of the West Antarctic ice-sheet is accelerating, where the average mass loss trend increases from -37.7 Gt/yr in 2003- 2008 to -156.0 Gt/yr in 2009- 2013. The melting trends in East Antarctic tend to stable before 2009, while after 2009 the mass of East Antarctic tends to increase faster and faster. During the studying period, the melting trend and acceleration of the East Ant- arctic and West Antarctic are （28±13.4）Gt/a, （9.8±2.8） Gt/a2and （--108.1±3.5） Gt/a, （-21.1±2.9） Gt/a2, respectively. The Antarctic ice-sheet mass loss mainly results from the mass loss of West Antarctic. Strong annual signal can be found in Antarctic, while the amplitude of mass change reaches the maximum values in about every October. Semi-annual variation mainly exists in the West Antarctic. The maximum amplitude of S2 tide impact is 25 mm which exists in Ronne ice-sheet.