Warmer early instrumental measurements versus colder reconstructed temperatures:: shooting at a moving target
Warmer early instrumental measurements versus colder reconstructed temperatures:: shooting at a moving target
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DOI：
10.1016/j.quascirev.2007.08.002
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发表时间：
2007-12-01
影响因子：
4
通讯作者：
Esper, Jan
中科院分区：
文献类型：
--
作者：
Frank, David;Buentgen, Ulf;Esper, Jan
比较树木年轮为基础的暖季温度重建和他们的仪器目标数据显示（温暖）早期仪器测量和（冷）代理估计之间的显着分歧。在这里，我们详细介绍了类似于1900年之前的北方半球和类似于1850年之前的欧洲阿尔卑斯山的系统失配。代理和目标的不确定性相关的五个假设来解释这一现象。其中包括：（1）树木年轮去趋势方法，（2）代理时间序列中的生物持久性，（3）生长对给定气候参数的响应的不确定性和不稳定性，（4）及时减少仪器站的可用性，以及（5）仪器数据的同质性。我们认为，在半球尺度的仪器目标的选择，仪器数据的不均匀性在阿尔卑斯山，也可能是半球尺度的不确定性是最重要的因素，在解释这种偏移。在更大尺度上评估均匀性仍然具有挑战性。提请注意早期温度计的庇护所和代理/目标差异的理解和量化幅度最近的人为和过去的自然强迫气候波动的相关性可能温暖的偏见。(c)2007爱思唯尔有限公司保留所有权利。
Comparison of tree-ring-based warm-season temperature reconstructions and their instrumental target data reveals substantial divergence between (warmer) early instrumental measurements and (colder) proxy estimates. Here we detail this systematic misfit for the Northern Hemisphere before similar to 1900 and the European Alps before similar to 1850. Five hypotheses related to both proxy and target uncertainties are presented towards explaining this phenomenon. These include: (1) tree-ring detrending methods, (2) biological persistence in the proxy time-series, (3) uncertainties and instabilities in the growth response to given climatic parameters, (4) reduced instrumental station availability back in time, and (5) instrumental data homogeneity. We suggest that uncertainties in the choice of instrumental targets at the hemispheric scale, and instrumental data inhomogeneities at the Alpine and possibly also the hemispheric-scale are the most important factors in explaining this offset. Assessment of homogeneity at larger scales remains challenging. Attention is drawn to possible warm biases in early thermometer shelters and the relevance of proxy/target discrepancies for understanding and quantifying the amplitude of both recent anthropogenic and past natural forced climate fluctuations. (c) 2007 Elsevier Ltd. All rights reserved.