From circumpolar deep water to the glacial meltwater plume on the eastern Amundsen Shelf
From circumpolar deep water to the glacial meltwater plume on the eastern Amundsen Shelf
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DOI：
10.1016/j.dsr.2013.04.001
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发表时间：
2013-07-01
影响因子：
2.4
通讯作者：
Hellmer, H. H.
中科院分区：
文献类型：
--
作者：
Nakayama, Y.;Schroeder, M.;Hellmer, H. H.
自20世纪90年代以来，松岛冰架（PIIS）的融化速度加快，这可能对冰盖动力学、海平面上升和周围海洋水团性质的变化产生重大影响。PIIS融化的原因是相对温暖（约1.2摄氏度）的环极深水（CDW）通过位于阿蒙森海大陆架的两个海底冰川槽渗透到PIIS空洞中。本研究主要分析了2010年ANTXXVI/3期间的水文资料，重点分析了CDW的入侵路径、PIIS的融化速率以及冰川融水的命运。我们根据侵入性CDW和融水含量将CTD剖面划分为6组。从这个分析中可以看出，温度高于1.23℃（低于1.23℃）的CDW通过东部（中央）槽侵入。温度由侵入CDW层的厚度控制。东部海槽支持的CDW层比松岛海槽（PIT）的水团更密集。东部侵入通过与来自中央槽的较轻和较冷的CDW混合而改变。利用冰架前沿CTD剖面的海洋运输和示踪剂运输计算，估计2010年的融化速率接近30 m /年（-1），与已公布的值相当。从融水含量的空间分布来看，融水沿水深线向西流动。与早期（2000年）的观测结果相比，2007-2010年期间松岛海槽观测到的CDW层变暖、变厚，表明CDW侵入最近变厚了。(C) 2013 Elsevier Ltd.版权所有。
The melting of Pine Island Ice Shelf (PIIS) has increased since the 1990 s, which may have a large impact on ice sheet dynamics, sea-level rise, and changes in water mass properties of surrounding oceans. The reason for the PIIS melting is the relatively warm (similar to 1.2 degrees C) Circumpolar Deep Water (CDW) that penetrates into the PIIS cavity through two submarine glacial troughs located on the Amundsen Sea continental shelf. In this study, we mainly analyze the hydrographic data obtained during ANTXXVI/3 in 2010 with the focus on pathways of the intruding CDW, PIIS melt rates, and the fate of glacial meltwater. We analyze the data by dividing CTD profiles into 6 groups according to intruding CDW properties and meltwater content. From this analysis, it is seen that CDW warmer than 1.23 degrees C (colder than 1.23 degrees C) intrudes via the eastern (central) trough. The temperature is controlled by the thickness of the intruding CDW layer. The eastern trough supports a denser CDW layer than the water mass in Pine Island Trough (PIT). The eastern intrusion is modified on the way into PIT through mixing with the lighter and colder CDW from the central trough. Using ocean transport and tracer transport calculations from the ice shelf front CTD section, the estimated melt rate in 2010 is similar to 30 m yr(-1), which is comparable to published values. From spatial distributions of meltwater content, meltwater flows along the bathymetry towards the west. When compared with earlier (2000) observations, a warmer and thicker CDW layer is observed in Pine Island Trough for the period 2007-2010, indicating a recent thickening of the CDW intrusion. (C) 2013 Elsevier Ltd. All rights reserved.