Last-millennium summer-temperature variations in western Europe based on proxy data
Last-millennium summer-temperature variations in western Europe based on proxy data
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DOI：
10.1191/0959683605hl819rp
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发表时间：
2005-05
期刊：
影响因子：
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通讯作者：
J. Guiot;A. Nicault;C. Rathgeber;Jl Edouard;F. Guibal;G. Pichard;C. Till
中科院分区：
文献类型：
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作者：
J. Guiot;A. Nicault;C. Rathgeber;Jl Edouard;F. Guibal;G. Pichard;C. Till
我们提出了一种方法的多代理重建欧洲的气候在过去的千年。所使用的代用指标包括长树轮宽度系列、葡萄收获日期、格陵兰冰氧同位素系列和基于历史文献的温度指数。使用西欧4月至9月的网格平均温度校准代理，即，在10°W和20°E之间，在35°N和55°N之间。他们也校准使用长期仪器夏季温度系列的马赛天文台的Longchamp，这开始于中十八世纪。该方法是一个模拟技术，这是能够处理丢失的数据，人工神经网络技术的最佳非线性校准和自举技术的重建计算误差酒吧的组合。约70%的温度变化被重建。过去的温度变化的幅度是特别好的重建，这是很重要的，当考虑到最近的温度趋势是或不是在自然变率。似乎在过去的一千年中，只有14次达到20世纪世纪的最后十年的温度。相对于其他多代理和钻孔温度重建的重建进行了讨论。我们的结论是，重建这样的我们，一个特定的区域重点（而不是更大的北方半球）是更可靠的，是在更好的协议与钻孔的结果，即使考虑到的事实，只有一部分的长期方差重建。小冰河时代（Little Ice Age）公元1560年至1930年）的夏季比1961年至1990年的夏季低0.2±0.5°C。钻孔温度表明冷却了0.4°C，其福尔斯落在我们重建的95%置信区间内。
We present a method of multiproxy reconstruction of the climate of Europe during the last millennium. The proxies used comprise long tree-ring width series, grape harvest dates, Greenland ice oxygen isotope series and temperature indices based on historical documents. The proxies are calibrated using gridded April to September mean temperatures for western Europe, i.e., between 10°W and 20°E and between 35°N and 55°N. They are calibrated also using the long instrumental summer temperature series of the Marseilles observatory of Longchamp, which begins in the mid-eighteenth century. The method is a combination of an analogue technique, which is able to deal with missing data, an artificial neural network technique for an optimal non-linear calibration and a bootstrap technique for calculating error bars on the reconstruction. About 70% of the temperature variance is reconstructed. The amplitude of the past temperature variations is particularly well reconstructed, which is important when considering whether the recent temperature trend is or is not within the natural variability It appears that the temperature of the last decade of the twentieth century was reached only 14 times during the last millennium. The reconstruction is discussed with respect to other multiproxy and borehole temperature reconstructions. We conclude that a reconstruction such ours, with a specific regional focus (as opposed to the larger Northern Hemisphere) is more reliable and is in better agreement with borehole results, even allowing for the fact that only a part of the long-term variance is reconstructed. ‘Little Ice Age’ (c. AD 1560-1930) summers were 0.2±0.5°C cooler than the 1961-1990 period. Borehole temperatures indicate a cooling of 0.4°C which falls in the 95% confidence interval of our reconstructions.