Abrupt Bølling warming and ice saddle collapse contributions to the Meltwater Pulse 1a rapid sea level rise.
Abrupt Bølling warming and ice saddle collapse contributions to the Meltwater Pulse 1a rapid sea level rise.
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DOI：
10.1002/2016gl070356
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发表时间：
2016-09-16
影响因子：
5.2
通讯作者：
Ivanovic, Ruza
中科院分区：
文献类型：
--
作者：
Gregoire, Lauren J.;Otto-Bliesner, Bette;Valdes, Paul J.;Ivanovic, Ruza
冰川融化引起的最大海平面快速上升(14-18 m，不到340 年，14,600 年前)，其来源(S)对于理解冰川快速融化的机制及其与气候突变的联系具有重要意义。在这里，我们通过使用过去21,000 年的两次瞬时气候模拟来驱动冰盖模型，来量化北美冰盖对融水脉冲1a的贡献程度和机制。冰盖扰动物理集合被用来解释模型的不确定性，通过重建21,000 年前到现在的冰范围和体积来约束冰的范围和体积。我们确定，北美冰盖在340 年中产生了3-4 m的全球平均海平面上升，这是由于Bölling的突然变暖，但当它触发冰盖鞍部崩塌时，这种响应被放大到5-6 m。有记录以来最大的海平面快速上升--融水脉冲1a(14.6 ka)的原因尚未解决。我们量化了北美冰盖对融水脉冲1a的贡献有多少以及通过什么机制。博林变暖可能触发了鞍形坍塌机制，对北美冰盖的MWP1a贡献了5-6 m或更多
Elucidating the source(s) of Meltwater Pulse 1a, the largest rapid sea level rise caused by ice melt (14–18 m in less than 340 years, 14,600 years ago), is important for understanding mechanisms of rapid ice melt and the links with abrupt climate change. Here we quantify how much and by what mechanisms the North American ice sheet could have contributed to Meltwater Pulse 1a, by driving an ice sheet model with two transient climate simulations of the last 21,000 years. Ice sheet perturbed physics ensembles were run to account for model uncertainties, constraining ice extent and volume with reconstructions of 21,000 years ago to present. We determine that the North American ice sheet produced 3–4 m global mean sea level rise in 340 years due to the abrupt Bølling warming, but this response is amplified to 5–6 m when it triggers the ice sheet saddle collapse. The cause of the largest rapid sea level rise ever recorded, Meltwater Pulse 1a (14.6 ka), is unresolved We quantify how much and by what mechanisms the North American ice sheet could have contributed to Meltwater Pulse 1a The Bolling warming likely triggered the saddle collapse mechanism contributing 5‐6 m or more to MWP1a from the North American ice sheet