Spatial reconstruction of Scottish summer temperatures from tree rings
Spatial reconstruction of Scottish summer temperatures from tree rings
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DOI：
10.1002/joc.4796
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发表时间：
2017-03
期刊：
影响因子：
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通讯作者：
M. Rydval;B. Gunnarson;N. Loader;E. Cook;D. Druckenbrod;R. Wilson
中科院分区：
文献类型：
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作者：
M. Rydval;B. Gunnarson;N. Loader;E. Cook;D. Druckenbrod;R. Wilson
对过去温度变化的时间模式和空间表现的详细了解对于将最近的人为气候变化放在更长期的背景下是重要的。为了填补目前对西北欧温度变率认识上的空白，采用逐点主成分回归方法重建了苏格兰地区0.5°温度网格的空间场。利用几种去趋势和干扰校正程序的组合以及树轮参数的选择[包括年轮宽度(RW)、最大晚材密度(MXD)和蓝色强度(BI)]来评估重建技能。重建场的高分辨率也是在空间上评估局部年表的温度重建潜力的诊断工具。最好的重建结果，在1901-1976年期间在苏格兰中部达到了校准R2=65.8%和验证R2=63.7%，使用经过干扰校正和无信号去趋势的RW年表与BI数据合并，在低通(高通)过滤RW(BI)年表后获得了最好的重建结果。苏格兰中部、北部和东部的校正和验证R2>；50%，西部和西北部的>；40%，苏格兰南部的>；30%，几乎所有网格的验证都显示出一定的重建技能。然而，苏格兰中部以外地区重建的完全校准潜力因扰动校正程序未发现的残留扰动趋势或可能对气候信号强度产生不利影响的其他气候或非气候因素而降低。
A detailed understanding of past temporal patterns and spatial expression of temperature variations is important to place recent anthropogenic climate change into a longer term context. In order to fill the current gap in our understanding of northwest European temperature variability, point‐by‐point principal component regression was used to reconstruct a spatial field of 0.5° temperature grids across Scotland. A sequence of reconstructions utilizing several combinations of detrending and disturbance correction procedures, and a selection of tree‐ring parameters [including ring width (RW), maximum latewood density (MXD) and blue intensity (BI)] was used in an evaluation of reconstruction skill. The high resolution of the reconstructed field serves also as a diagnostic tool to spatially assess the temperature reconstruction potential of local chronologies. Best reconstruction results, reaching calibration r2 = 65.8% and verification r2 = 63.7% in central Scotland over the 1901–1976 period, were achieved using disturbance‐corrected and signal‐free detrended RW chronologies merged with BI data after low‐pass (high‐pass) filtering the RW (BI) chronologies. Calibration and verification r2 > 50% was attained for central, north and east Scotland, >40% in west and northwest, and >30% in southern Scotland with verification of nearly all grids showing some reconstruction skill. However, the full calibration potential of reconstructions outside central Scotland was reduced either due to residual disturbance trends undetected by the disturbance correction procedure or due to other climatic or non‐climatic factors which may have adversely affected the strength of the climate signal.