Regional Antarctic snow accumulation over the past 1000 years
Regional Antarctic snow accumulation over the past 1000 years
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DOI：
10.5194/cp-13-1491-2017
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发表时间：
2017-11-10
影响因子：
4.3
通讯作者：
Ekaykin, Alexey A.
中科院分区：
文献类型：
--
作者：
Thomas, Elizabeth R.;van Wessem, J. Melchior;Ekaykin, Alexey A.
在这里，我们提出了在过去1000年的区域尺度南极积雪的变化。总共收集了79个冰芯积雪记录，并分配到7个地理区域，将海拔2000米以下的高积累沿海地区与干燥的南极中部高原分开。根据RACMO2.3p2模拟的表面质量平衡（SMB）和ERA中期再分析的降水，对年度积雪的区域复合材料进行了评估。除威德尔海海岸外，低海拔复合材料捕获了模型定义的区域降水和SMB变化。南极中部的站点缺乏一致性，要么不代表区域降水，要么表明模型无法捕捉相关的降水过程中的寒冷，干燥的中央高原。我们的研究结果表明，自1800年以来，南极冰盖（包括冰架）的SMB以7 +/- 0.13 Gt的速度增加，表示自1800年以来海平面净减少了0.02 mm，自1900年以来海平面净减少了0.04 mm。最大的贡献来自南极半岛（类似于75%），在最近十年（2001-2010年）的年平均SMB比19世纪前十年的年平均值高123 +/- 44 Gt yr（-1）。只有四个冰芯记录涵盖了整个1000年，他们建议在此期间雪积累减少。然而，我们的研究强调了低海拔沿海地区的重要性，这在以前的时间积雪调查中一直代表性不足。
Here we present Antarctic snow accumulation variability at the regional scale over the past 1000 years. A total of 79 ice core snow accumulation records were gathered and assigned to seven geographical regions, separating the high-accumulation coastal zones below 2000m of elevation from the dry central Antarctic Plateau. The regional composites of annual snow accumulation were evaluated against modelled surface mass balance (SMB) from RACMO2.3p2 and precipitation from ERA-Interim reanalysis. With the exception of the Weddell Sea coast, the low-elevation composites capture the regional precipitation and SMB variability as defined by the models. The central Antarctic sites lack coherency and either do not represent regional precipitation or indicate the model inability to capture relevant precipitation processes in the cold, dry central plateau. Our results show that SMB for the total Antarctic Ice Sheet (including ice shelves) has increased at a rate of 7 +/- 0.13 Gt decade(-1) since 1800 AD, representing a net reduction in sea level of similar to 0.02mm decade(-1) since 1800 and similar to 0.04mm decade(-1) since 1900 AD. The largest contribution is from the Antarctic Peninsula (similar to 75 %) where the annual average SMB during the most recent decade (2001-2010) is 123 +/- 44 Gt yr(-1) higher than the annual average during the first decade of the 19th century. Only four ice core records cover the full 1000 years, and they suggest a decrease in snow accumulation during this period. However, our study emphasizes the importance of low-elevation coastal zones, which have been under-represented in previous investigations of temporal snow accumulation.