An investigation of Glacial Isostatic Adjustment over the Amundsen Sea sector, West Antarctica
An investigation of Glacial Isostatic Adjustment over the Amundsen Sea sector, West Antarctica
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DOI：
10.1016/j.gloplacha.2012.08.001
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发表时间：
2012-12-01
影响因子：
3.9
通讯作者：
Dietrich, R.
中科院分区：
文献类型：
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作者：
Groh, A.;Ewert, H.;Dietrich, R.
本研究的重点是阿蒙森海，这是南极冰盖（AIS）最具动力的区域。基于重力恢复与气候试验（GRACE）观测到的质量变化盆地估计和冰云和陆地高程卫星（ICESat）观测到的体积变化，推导了冰川均衡调整（CIA）引起的平均质量变化。这意味着CIA引起的质量变化为34.1 +/- 11.9 Gt/年，这明显大于当前CIA模型的预测。结果表明，阿蒙森海区域相应的平均高程变化为23.3 +/- 7.7 mm/yr，与三个GPS站点观测所得的隆升率吻合较好。利用ICESat观测资料，对观测到的抬升率进行了校正，校正了由于现今冰块变化造成的弹性变形。根据grace导出的质量变化估计值和推断出的CIA校正值，我们推断阿蒙森海目前的冰质量损失为-98.9 +/- 13.7 Gt/年。这相当于全球海平面上升0.27±0.04毫米/年。与依靠中央情报局模型预测的结果相比，这相当于冰质量损失或海平面上升分别增加了约40%。(C) 2012 Elsevier B.V.版权所有
The present study focuses on the Amundsen Sea sector which is the most dynamical region of the Antarctic Ice Sheet (AIS). Based on basin estimates of mass changes observed by the Gravity Recovery and Climate Experiment (GRACE) and volume changes observed by the Ice, Cloud and Land Elevation Satellite (ICESat), the mean mass change induced by Glacial Isostatic Adjustment (CIA) is derived. This mean CIA-induced mass change is found to be 34.1 +/- 11.9 Gt/yr, which is significantly larger than the predictions of current CIA models. We show that the corresponding mean elevation change of 23.3 +/- 7.7 mm/yr in the Amundsen Sea sector is in good agreement with the uplift rates obtained from observations at three GPS sites. Utilising ICESat observations, the observed uplift rates were corrected for elastic deformations due to present-day ice-mass changes. Based on the GRACE-derived mass change estimate and the inferred CIA correction, we inferred a present-day ice-mass loss of -98.9 +/- 13.7 Gt/yr for the Amundsen Sea sector. This is equivalent to a global eustatic sea-level rise of 0.27 +/- 0.04 mm/yr. Compared to the results relying on CIA model predictions, this corresponds to an increase of the ice-mass loss or sea-level rise, respectively, of about 40%. (C) 2012 Elsevier B.V. All rights reserved.