Impact of Atmospheric Circulation on Temperature, Clouds, and Radiation at Summit Station, Greenland, with Self-Organizing Maps
Impact of Atmospheric Circulation on Temperature, Clouds, and Radiation at Summit Station, Greenland, with Self-Organizing Maps
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DOI：
10.1175/jcli-d-17-0893.1
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发表时间：
2018-10
影响因子：
4.9
通讯作者：
Michael R. Gallagher;M. Shupe;N. B. Miller
中科院分区：
文献类型：
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作者：
Michael R. Gallagher;M. Shupe;N. B. Miller
格陵兰冰盖（GrIS）在北极气候中起着至关重要的作用，大气条件是物质平衡的主要调节因素。这项分析建立了大尺度大气环流和GrIS质量平衡的主要决定因素之间的关系：水分，云的特性，辐射强迫和温度。使用自组织地图（SOM），从能源，云，大气状态和降水的综合表征在首脑会议（ICECAPS）项目的观测进行分类的每日海平面压力（SLP）梯度。结果详细描述了如何南，北，纬向环流制度的影响，格陵兰岛首脑会议站的观测。这种向南的制度是联系在一起的大的异常增加，在低层液体云的形成，云辐射强迫（CRF），和表面变暖的首脑会议站。一个单独的偏南模式与最大的正距平相关，最极端的25%的情况导致CRF距平超过21 W m−2，温度距平超过8.5°C。最后，2012年7月极端融化事件进行了分析，表明长期冰盖变暖与这些偏南环流模式的持续性有关，导致异常的CRF和温度的异常延长期。这些结果展示了一种新的方法，将每日大气环流与相对简短的观测记录联系起来。
The Greenland Ice Sheet (GrIS) plays a crucial role in the Arctic climate, and atmospheric conditions are the primary modifier of mass balance. This analysis establishes the relationship between large-scale atmospheric circulation and principal determinants of GrIS mass balance: moisture, cloud properties, radiative forcing, and temperature. Using self-organizing maps (SOMs), observations from the Integrated Characterization of Energy, Clouds, Atmospheric State, and Precipitation at Summit (ICECAPS) project are categorized by daily sea level pressure (SLP) gradient. The results describe in detail how southerly, northerly, and zonal circulation regimes impact observations at Summit Station, Greenland. This southerly regime is linked to large anomalous increases in low-level liquid cloud formation, cloud radiative forcing (CRF), and surface warming at Summit Station. An individual southerly pattern relates to the largest positive anomalies, with the most extreme 25% of cases leading to CRF anomalies above 21 W m−2 and temperature anomalies beyond 8.5°C. Finally, the July 2012 extreme melt event is analyzed, showing that the prolonged ice sheet warming was related to persistence of these southerly circulation patterns, causing an unusually extended period of anomalous CRF and temperature. These results demonstrate a novel methodology, connecting daily atmospheric circulation to a relatively brief record of observations.