Modeling Northern Hemispheric Ice Sheet Dynamics, Sea Level Change, and Solid Earth Deformation Through the Last Glacial Cycle
Modeling Northern Hemispheric Ice Sheet Dynamics, Sea Level Change, and Solid Earth Deformation Through the Last Glacial Cycle
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DOI：
10.1029/2020jf006040
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发表时间：
2021-03
期刊：
影响因子：
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通讯作者：
H. K. Han;N. Gomez;D. Pollard;R. DeConto
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文献类型：
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作者：
H. K. Han;N. Gomez;D. Pollard;R. DeConto
冰盖的退缩或前进会扰乱地球的固体表面、旋转矢量和引力场，这反过来又会反馈到冰盖在一定时间尺度上的演变。在整个末次冰期循环中，北半球的冰盖经历了多个生长和退缩阶段，但这些阶段的动力学尚不清楚。在这项研究中，我们应用一个耦合的冰盖-冰川均衡调整模式来模拟北半球冰盖在末次冰期的变化。我们的重点是了解与表面（冰和水）载荷变化相关的固体地球变形和重力场扰动对冰期不同阶段陆地和海洋冰盖动力学的影响。研究结果表明，固体地球变形通过冰高程反馈增强了陆地区域生长期的冰川作用和退缩期的融化作用，重力场扰动通过海平面反馈对北美哈德逊湾、欧亚大陆巴伦支海和喀拉海等地区退缩期的海洋冰盖具有稳定作用。我们的研究结果还表明，固体地球变形影响了北美和欧亚冰盖对气候的相对敏感性，从而影响了它们在整个末次冰期周期中波动的时间和幅度。
Retreat or advance of an ice sheet perturbs the Earth's solid surface, rotational vector, and the gravitational field, which in turn feeds back onto the evolution of the ice sheet over a range of timescales. Throughout the last glacial cycle, ice sheets over the Northern Hemisphere have gone through multiple growth and retreat phases, but the dynamics during these phases are not well understood. In this study, we apply a coupled ice sheet‐glacial isostatic adjustment model to simulate the Northern Hemisphere Ice Sheets over the last glacial cycle. We focus on understanding the influence of solid Earth deformation and gravitational field perturbations associated with surface (ice and water) loading changes on the dynamics of terrestrial and marine‐based ice sheets during different phases of the glacial cycle. Our results show that solid Earth deformation enhances glaciation during growth phases and melting during retreat phases in terrestrial regions through ice‐elevation feedback, and gravitational field perturbations have a stabilizing influence on marine‐based ice sheets in regions such as Hudson Bay in North America and Barents and Kara Seas in Eurasia during retreat phases through sea‐level feedback. Our results also indicate that solid Earth deformation influences the relative sensitivity of the North American and Eurasian ice sheets to climate and thus the timing and magnitude of their fluctuations throughout the last glacial cycle.