Briffa Keith R, Shishov Vladimir V, Melvin Thomas M, Vaganov Eugene A, Grudd Håken, Hantemirov Rashit M, Eronen Matti, Naurzbaev Muktar M
Climatic Research Unit, School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, UK.
Philos Trans R Soc Lond B Biol Sci. 2008 Jul 12;363(1501):2271-84. doi: 10.1098/rstb.2007.2199.
This paper describes variability in trends of annual tree growth at several locations in the high latitudes of Eurasia, providing a wide regional comparison over a 2000-year period. The study focuses on the nature of local and widespread tree-growth responses to recent warming seen in instrumental observations, available in northern regions for periods ranging from decades to a century. Instrumental temperature data demonstrate differences in seasonal scale of Eurasian warming and the complexity and spatial diversity of tree-growing-season trends in recent decades. A set of long tree-ring chronologies provides empirical evidence of association between inter-annual tree growth and local, primarily summer, temperature variability at each location. These data show no evidence of a recent breakdown in this association as has been found at other high-latitude Northern Hemisphere locations. Using Kendall's concordance, we quantify the time-dependent relationship between growth trends of the long chronologies as a group. This provides strong evidence that the extent of recent widespread warming across northwest Eurasia, with respect to 100- to 200-year trends, is unprecedented in the last 2000 years. An equivalent analysis of simulated temperatures using the HadCM3 model fails to show a similar increase in concordance expected as a consequence of anthropogenic forcing.
本文描述了欧亚大陆高纬度地区多个地点树木年生长趋势的变异性，给出了2000年期间广泛的区域对比。该研究聚焦于仪器观测中所见到的局部和广泛的树木生长对近期变暖的响应特性，北方地区有几十年到一个世纪不等的仪器观测数据。仪器温度数据表明了欧亚大陆变暖的季节尺度差异以及近几十年来树木生长季趋势的复杂性和空间多样性。一组长树轮年表提供了每年树木生长与每个地点局部（主要是夏季）温度变异性之间关联的实证证据。这些数据没有显示出如在北半球其他高纬度地区所发现的近期这种关联的中断迹象。我们使用肯德尔和谐系数，将这些长年表的生长趋势作为一个整体来量化随时间变化的关系。这提供了强有力的证据，表明就100至200年的趋势而言，近期欧亚大陆西北部广泛变暖的程度在过去2000年里是前所未有的。使用HadCM3模型对模拟温度进行的等效分析未能显示出因人为强迫作用而预期的类似和谐系数增加情况。
