Western Greenland ice sheet retreat history reveals elevated precipitation during the Holocene thermal maximum
Western Greenland ice sheet retreat history reveals elevated precipitation during the Holocene thermal maximum
复制标题
格陵兰岛西部冰盖消退历史表明全新世热峰期间降水量增加
DOI：
10.5194/tc-14-1121-2020
复制
发表时间：
2020
期刊：
影响因子：
--
通讯作者：
J. Cuzzone
中科院分区：
文献类型：
--
作者：
Jacob Downs;Jesse Johnson;J. Briner;N. Young;A. Lesnek;J. Cuzzone
抽象的。采用全新世冰盖末端位置年表和一种新的基于无迹变换(UT)的反模拟方法，研究了全新世最热盛期(HTM)期间格陵兰中西部Kangerlussuaq地区降水模式的变化。UT用于估计年降水量的变化，以减少模型和观测终端位置之间的不匹配。我们证明了UT在时间相关数据同化中的有效性，强调了它的低计算成本和简单的并行实现。我们的结果表明，全新世变暖与降水量增加相吻合，如果没有降雨量的增加，康格尔卢斯苏阿克地区的模拟退缩比观测所建议的要快得多。不太确定的是，HTM期间的高温是否特别与降水的瞬时增加有关，因为结果取决于假设的温度历史。我们的结果突出了变化的降水模式在控制全新世冰盖范围方面所起的重要作用。
Abstract. We investigate changing precipitation patterns in the Kangerlussuaq region of western central Greenland during the Holocene thermal maximum (HTM), using a new chronology of ice sheet terminus position through the Holocene and a novel inverse modeling approach based on the unscented transform (UT). The UT is applied to estimate changes in annual precipitation in order to reduce the misfit between modeled and observed terminus positions. We demonstrate the effectiveness of the UT for time-dependent data assimilation, highlighting its low computational cost and trivial parallel implementation. Our results indicate that Holocene warming coincided with elevated precipitation, without which modeled retreat in the Kangerlussuaq region is more rapid than suggested by observations. Less conclusive is whether high temperatures during the HTM were specifically associated with a transient increase in precipitation, as the results depend on the assumed temperature history. Our results highlight the important role that changing precipitation patterns had in controlling ice sheet extent during the Holocene.