The influence of atmospheric circulation on the mid-Holocene climate of Europe: a data–model comparison
The influence of atmospheric circulation on the mid-Holocene climate of Europe: a data–model comparison
复制标题
DOI：
10.5194/cp-10-1925-2014
复制
发表时间：
2013-10
影响因子：
4.3
通讯作者：
A. Mauri;B. Davis;B. Davis;P. Collins;J. Kaplan;J. Kaplan
中科院分区：
文献类型：
--
作者：
A. Mauri;B. Davis;B. Davis;P. Collins;J. Kaplan;J. Kaplan
抽象的。大气环流是未来气候变化的气候模型模拟中不确定性的关键领域，特别是在欧洲等中纬度地区，那里的大气动力学对气候变化起着重要作用。有人提出，欧洲全新世中期的特点是冬季西风环流较强，与 AO/NAO 正值相当，而夏季西风环流则较弱，原因是斯堪的纳维亚半岛附近的反气旋阻塞。模型模拟充其量仅表明 AO/NAO 呈弱正值，而夏季大气环流的变化尚未得到广泛研究。在这里，我们使用基于花粉的欧洲全新世中期气候的新重建来研究大气环流在解释季节性温度和降水异常的空间格局中的作用。我们发现异常的足迹与现代模拟大气环流模式的足迹完全一致，这些模式与冬季强西风环流（正AO/NAO）和夏季弱西风环流与反气旋阻塞（正SCAND）相关。我们发现重建的异常与作为 PMIP3/CMIP5 项目一部分进行全新世中期实验的 14 个 GCM 的异常之间几乎没有一致性，这些实验显示出对太阳照射的顶层大气变化的敏感性要高得多。我们的研究结果与当代时间尺度的数据模型比较一致，表明模型低估了大气环流在近期气候变化中的作用，同时也强调了大气动力学在解释间冰期变暖方面的重要性。
Abstract. The atmospheric circulation is a key area of uncertainty in climate model simulations of future climate change, especially in mid-latitude regions such as Europe where atmospheric dynamics have a significant role in climate variability. It has been proposed that the mid-Holocene was characterized in Europe by a stronger westerly circulation in winter comparable with a more positive AO/NAO, and a weaker westerly circulation in summer caused by anti-cyclonic blocking near Scandinavia. Model simulations indicate at best only a weakly positive AO/NAO, whilst changes in summer atmospheric circulation have not been widely investigated. Here we use a new pollen-based reconstruction of European mid-Holocene climate to investigate the role of atmospheric circulation in explaining the spatial pattern of seasonal temperature and precipitation anomalies. We find that the footprint of the anomalies is entirely consistent with those from modern analogue atmospheric circulation patterns associated with a strong westerly circulation in winter (positive AO/NAO) and a weak westerly circulation in summer associated with anti-cyclonic blocking (positive SCAND). We find little agreement between the reconstructed anomalies and those from 14 GCMs that performed mid-Holocene experiments as part of the PMIP3/CMIP5 project, which show a much greater sensitivity to top-of-the-atmosphere changes in solar insolation. Our findings are consistent with data–model comparisons on contemporary timescales that indicate that models underestimate the role of atmospheric circulation in recent climate change, whilst also highlighting the importance of atmospheric dynamics in explaining interglacial warming.