Simulated Atmospheric Response to Regional and Pan-Arctic Sea Ice Loss
Simulated Atmospheric Response to Regional and Pan-Arctic Sea Ice Loss
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DOI：
10.1175/jcli-d-16-0197.1
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发表时间：
2017-06-01
影响因子：
4.9
通讯作者：
Screen, James A.
中科院分区：
文献类型：
--
作者：
Screen, James A.
北极海冰的消失已经对当地的环境、社会和生态产生了深远的影响。然而，科学研究的一个高度不确定的领域是，这种北极变化是否对低纬度地区的天气和气候产生切实的影响。越来越多的证据表明，海冰消失的地理位置对于确定大规模大气环流响应和相关的中纬度影响至关重要。然而，这种区域依赖性尚未得到彻底和系统的探讨。为了在这个问题上取得进展，本研究分析了北极九个地区分别规定海冰损失的大气环流模型的集合模拟，以阐明对区域海冰损失的不同反应。结果表明，在某些地区，海冰消失引发大规模的动力学响应，而在其他地区，海冰消失仅引起局部热力学变化。巴伦支海和卡拉海的海冰损失在驱动平流层极地涡旋减弱方面具有独特的作用，随后会出现类似于北大西洋涛动的对流层环流响应。 10月至3月，最大的空间尺度响应是由巴伦支海-喀拉海和鄂霍次克海的海冰损失驱动的；然而，不同地区在其他季节显得更为重要。大气对区域海冰损失的响应与对泛北极海冰损失的响应非常不同，并且不能通过对区域海冰损失的响应的线性相加来获得对泛北极海冰损失的响应。结果表明，过去对北极海冰消失的模拟响应研究的多样性可以部分地用海冰消失的不同空间模式来解释。
The loss ofArctic sea ice is already having profound environmental, societal, and ecological impacts locally. A highly uncertain area of scientific research, however, is whether such Arctic change has a tangible effect on weather and climate at lower latitudes. There is emerging evidence that the geographical location of sea ice loss is critically important in determining the large-scale atmospheric circulation response and associated midlatitude impacts. However, such regional dependencies have not been explored in a thorough and systematicmanner. To make progress on this issue, this study analyzes ensemble simulations with an atmospheric general circulation model prescribed with sea ice loss separately in nine regions of the Arctic, to elucidate the distinct responses to regional sea ice loss. The results suggest that in some regions, sea ice loss triggers large-scale dynamical responses, whereas in other regions sea ice loss induces only local thermodynamical changes. Sea ice loss in the BarentsKara Seas is unique in driving a weakening of the stratospheric polar vortex, followed in time by a tropospheric circulation response that resembles the NorthAtlanticOscillation. For October-March, the largest spatial-scale responses are driven by sea ice loss in the Barents-Kara Seas and the Sea ofOkhotsk; however, different regions assume greater importance in other seasons. The atmosphere responds very differently to regional sea ice losses than to pan-Arctic sea ice loss, and the response to pan-Arctic sea ice loss cannot be obtained by the linear addition of the responses to regional sea ice losses. The results imply that diversity in past studies of the simulated response to Arctic sea ice loss can be partly explained by the different spatial patterns of sea ice loss imposed.