NOAA/WDS Paleoclimatology - Touchan - Ain Khala - CDAT - ITRDB MAR029

The first large-scale network of tree-ring chronologies from the western Mediterranean (WM; 32°N–43°N, 10°W–17°E) is described and analyzed to identify the seasonal climatic signal in indices of annual ring width. Correlation and rotated empirical orthogonal function analyses are applied to 85 tree-ring series and corresponding gridded climate data to assess the climate signal embedded in the network. Chronologies range in length from 80 to 1129 years. Monthly correlations and partial correlations show overall positive associations for Pinus halepensis (PIHA) and Cedrus atlantica (CDAT) with winter (December–February) and spring (March–May) precipitation across this network. In both seasons, the precipitation correlation with PIHA is stronger, while CDAT chronologies tend to be longer. A combination of positive correlations between growth and winter–summer precipitation and negative partial correlations with growing season temperatures suggests that chronologies in at least part of the network reflect soil moisture and the integrated effects of precipitation and evapotranspiration signal. The range of climate response observed across this network reflects a combination of both species and geographic influences. Western Moroccan chronologies have the strongest association with the North Atlantic Oscillation.

本研究对西地中海（Western Mediterranean, WM；32°N–43°N，10°W–17°E）首个大型树轮年表网络进行描述与分析，以识别年轮宽度指数中的季节性气候信号。
本研究采用相关分析与旋转经验正交函数（rotated empirical orthogonal function）分析法，对85组树轮序列及对应网格化气候数据开展处理，以此解析该网络所蕴含的气候信号。
所构建的树轮年表时长跨度为80至1129年。
月相关分析与偏相关分析结果显示，阿勒颇松（Pinus halepensis, PIHA）与大西洋雪松（Cedrus atlantica, CDAT）的生长指标与研究区域内冬季（12月—2月）及春季（3月—5月）降水整体呈正相关关系。
在上述两个季节中，阿勒颇松序列与降水的相关性更强，而大西洋雪松年表的时长普遍更长。
生长与冬夏降水呈正相关、同时与生长季温度呈负偏相关的组合特征表明，该网络至少部分区域的树轮年表反映了土壤湿度状况，以及降水与蒸散的综合气候信号。
本网络观测到的气候响应差异，是物种与地理因素共同作用的结果。其中，西摩洛哥地区的年表与北大西洋涛动（North Atlantic Oscillation）的相关性最为显著。