A fully coupled 3-D ice-sheet-sea-level model: algorithm and applications
A fully coupled 3-D ice-sheet-sea-level model: algorithm and applications
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DOI：
10.5194/gmd-7-2141-2014
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发表时间：
2014-01-01
影响因子：
5.1
通讯作者：
van de Wal, R. S. W.
中科院分区：
文献类型：
--
作者：
de Boer, B.;Stocchi, P.;van de Wal, R. S. W.
更新世晚期的相对海平面变化只能用冰盖历史的知识来重建。另一方面，了解区域和全球相对海平面变化是了解冰量变化的必要条件。要克服这种循环问题，需要一个完全耦合的系统，在这个系统中，冰盖和海平面在空间和时间上不断变化，并动态地相互影响。在这里，我们提出的结果在过去的41万年（410 kyr）从一组3-D冰盖架模型的耦合到全球海平面模型，这是基于重力自洽海平面方程的解决方案。海平面模型采用了冰川均衡调整反馈的麦克斯韦粘弹性和旋转地球模型与海岸迁移。冰量计算与四个三维冰架模式为北美，欧亚大陆，格陵兰岛和南极洲。使用逆的方法，冰量和温度来自底栖三角洲O-18叠加记录。导出的地表气温异常被添加到当今气候学中，以模拟冰川-间冰期的温度变化，从而模拟冰量。冰盖厚度的变化，然后转发到海平面模型计算基岩变形，海平面高度的变化，从而相对海平面的变化。然后将后者转发到冰盖模型。为了量化相对海平面变化对冰量演变的影响，我们进行了耦合和非耦合模拟。冰盖厚度变化的最大差异发生在冰盖边缘，相对海平面变化显著偏离海洋平均海平面变化。
Relative sea-level variations during the late Pleistocene can only be reconstructed with the knowledge of ice-sheet history. On the other hand, the knowledge of regional and global relative sea-level variations is necessary to learn about the changes in ice volume. Overcoming this problem of circularity demands a fully coupled system where ice sheets and sea level vary consistently in space and time and dynamically affect each other. Here we present results for the past 410 000 years (410 kyr) from the coupling of a set of 3-D ice-sheet-shelf models to a global sea-level model, which is based on the solution of the gravitationally self-consistent sea-level equation. The sea-level model incorporates the glacial isostatic adjustment feedbacks for a Maxwell viscoelastic and rotating Earth model with coastal migration. Ice volume is computed with four 3-D ice-sheet-shelf models for North America, Eurasia, Greenland and Antarctica. Using an inverse approach, ice volume and temperature are derived from a benthic delta O-18 stacked record. The derived surface-air temperature anomaly is added to the present-day climatology to simulate glacial-interglacial changes in temperature and hence ice volume. The ice-sheet thickness variations are then forwarded to the sea-level model to compute the bedrock deformation, the change in sea-surface height and thus the relative sea-level change. The latter is then forwarded to the ice-sheet models. To quantify the impact of relative sea-level variations on ice-volume evolution, we have performed coupled and uncoupled simulations. The largest differences of ice-sheet thickness change occur at the edges of the ice sheets, where relative sea-level change significantly departs from the ocean-averaged sea-level variations.