How unusual was autumn 2006 in Europe
How unusual was autumn 2006 in Europe
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DOI：
10.5194/cp-3-659-2007
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发表时间：
2007-11
影响因子：
4.3
通讯作者：
G. J. Oldenborgh
中科院分区：
文献类型：
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作者：
G. J. Oldenborgh
抽象的。2006年秋季，欧洲大部分地区的气温都创下了历史新高。与1961-1990年相比，从阿尔卑斯山北侧到挪威南部，2米的温度比正常温度高出3摄氏度。这使得英国、比利时、荷兰、丹麦、德国和瑞士有记录以来最热的秋天，英格兰中部的记录可以追溯到1659年，荷兰可以追溯到1706年，丹麦可以追溯到1768年。偏差如此之大，以至于在气候不发生变化的明显错误假设下，考虑到秋季气温定义的分布，欧洲大部分地区2006年观测到的气温出现的概率小于每10，000年一次。1901-2005年。对温度分布的更好描述是假设平均值与全球平均温度成比例变化，但分布的形状保持不变。这首先包括全球变暖的影响。即使在这种假设下，秋季的温度也非常不寻常，估计该地区的回归时间为200至2000年。95%置信区间的下限为100年至300年。除全球变暖外，偏南环流的线性效应的贡献最大，解释了约一半的异常。北海的海温异常也是沿着重要的异常。模拟当前大气环流的气候模型大大低估了观测到的秋季平均气温上升。它们没有模拟分布形状的变化，这种变化会增加全球变暖下温暖事件的概率。这意味着，2006年温暖的秋天要么是一个非常罕见的巧合，要么当地的温度上升比模拟的要强烈得多，或者这些模型中缺少的非线性物理增加了极端温暖的可能性。
Abstract. The temperatures in large parts of Europe have been record high during the meteorological autumn of 2006. Compared to 1961–1990, the 2 m temperature was more than three degrees Celsius above normal from the North side of the Alps to southern Norway. This made it by far the warmest autumn on record in the United Kingdom, Belgium, the Netherlands, Denmark, Germany and Switzerland, with the records in Central England going back to 1659, in the Netherlands to 1706 and in Denmark to 1768. The deviations were so large that under the obviously false assumption that the climate does not change, the observed temperatures for 2006 would occur with a probability of less than once every 10 000 years in a large part of Europe, given the distribution defined by the temperatures in the autumn 1901–2005. A better description of the temperature distribution is to assume that the mean changes proportional to the global mean temperature, but the shape of the distribution remains the same. This includes to first order the effects of global warming. Even under this assumption the autumn temperatures were very unusual, with estimates of the return time of 200 to 2000 years in this region. The lower bound of the 95% confidence interval is more than 100 to 300 years. Apart from global warming, linear effects of a southerly circulation are found to give the largest contributions, explaining about half of the anomalies. SST anomalies in the North Sea were also important along the coast. Climate models that simulate the current atmospheric circulation well underestimate the observed mean rise in autumn temperatures. They do not simulate a change in the shape of the distribution that would increase the probability of warm events under global warming. This implies that the warm autumn 2006 either was a very rare coincidence, or the local temperature rise is much stronger than modelled, or non-linear physics that is missing from these models increases the probability of warm extremes.