Evolution of the Antarctic ice sheet throughout the last deglaciation: A study with a new coupled climate—north and south hemisphere ice sheet model
Evolution of the Antarctic ice sheet throughout the last deglaciation: A study with a new coupled climate—north and south hemisphere ice sheet model
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上一次冰消期南极冰盖的演变：一项新的耦合气候——南北半球冰盖模型的研究
DOI：
10.1016/j.epsl.2006.06.017
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发表时间：
2006
影响因子：
5.3
通讯作者：
C. Dumas
中科院分区：
文献类型：
--
作者：
G. Philippon;G. Ramstein;S. Charbit;M. Kageyama;C. Ritz;C. Dumas
本文的目的是通过对冰川消融过程的了解，评估南极冰盖在最后一次冰川消融期间对海平面上升的贡献。为了实现这一目标，我们使用了一个地球系统模型，在这个模型中，大气、海洋、植被和南北冰盖之间的相互作用被表示出来。这个新工具可以模拟南极冰量的演变，它在15ka左右开始减少。在冰川消退结束时，南极冰盖的融化在标准实验中导致了相当于冰的海平面上升9.5米，在考虑威德尔海不同的水深测量的更现实的灵敏度实验中导致了17.5米的上升，威德尔海成功地产生了两个主要的冰架（Ross和Ronne-Filchner）。在这两个实验中，所有冰盖的融化分别贡献了121.5 m和129.5 m，这与数据非常一致。新的耦合模式提供了一个不同于先前将Vostok南极冰芯（78°27′s 106°52′e）的温度记录规定为均匀温度强迫而得到的南极消冰时间和幅度。还进行了敏感性试验，以分析消冰过程起源参数的影响：日照变化、大气二氧化碳变化、基底融化和海平面上升。所有这些参数都对冰川消融的时间有影响。所规定的全球海平面上升被证明是最后一次冰川消退期间南极冰量演变的一个主要强迫因素。我们量化了北半球冰盖融化对接地线后退造成的海平面上升的直接影响，这反过来又有利于通过降低冰架的支撑作用来增强接地冰流。
The aim of this paper is to assess, through the understanding of deglaciation processes, the contribution of the Antarctic ice sheet to sea-level rise during the last deglaciation. To achieve this goal, we use an Earth System model in which the interactions between the atmosphere, the ocean, the vegetation and the northern and Antarctic ice sheets are represented. This new tool allows the simulation of the evolution of the Antarctic ice volume, which starts to decrease at around 15 ka. At the end of deglaciation, the melting of the Antarctic ice sheet contributes to an ice-equivalent sea-level rise of 9.5 m in the standard experiment and 17.5 m in a more realistic sensitivity experiment accounting for a different bathymetry in the Weddell Sea which succeeds in producing both major ice shelves (Ross and Ronne-Filchner). In both experiments, the melting of all ice sheets contributes to 121.5 m and 129.5 m, respectively, which is very consistent with data. The new coupled model provides a timing and amplitude of the Antarctic deglaciation different from those previously obtained by prescribing the temperature record from the Vostok Antarctic ice core (78°27′S 106°52′E) as a uniform temperature forcing. Sensitivity experiments have also been performed to analyse the impact of the parameters at the origin of the deglaciation process: insolation changes, atmospheric CO2variation, basal melting and sea-level rise. All those parameters have an influence on the timing of the deglaciation. The prescribed global sea level rise is shown to be a major forcing factor for the evolution of the Antarctic ice volume during the last deglaciation. We quantify the direct effect of the sea-level rise due to the northern hemisphere ice sheet melting on the grounding line retreat which, in turn, favours enhancement of grounded ice flow by lowering the buttressing effect of ice shelves.