NOAA/WDS Paleoclimatology - Touchan - Akyol Deresi - PISY - ITRDB TUR056

The first large-scale network of 79 tree-ring chronologies in the Eastern Mediterranean and Near East (EMNE; 33°N–42°N, 21°E–43°E) is described and analyzed to identify the seasonal climatic signal in indices of annual ring width. Correlation analysis and cluster analysis are applied to tree-ring data and gridded climate data to assess the climate signal embedded in the network in preparation for climate field reconstructions and formal proxy/model intercomparison experiments. The lengths of the 79 combined chronologies range from 89 to 990 years. The monthly correlations and partial correlations reveal a pervasive positive association with May, June, and sometimes July precipitation, positive correlations with winter and spring (December through April) temperatures, and negative relationships with May through July temperature, although as expected, there are site-to-site exceptions to these general patterns. Cluster analysis suggests three groups of sites based on their association with climate. The chronologies for the EMNE have coherent seasonal precipitation and temperature signals across a fairly broad geographical domain. The predominant signal is a positive growth response to May–June precipitation. Collectively, the findings suggest that the network can be exploited to develop season-specific field reconstructions of precipitation and drought history in the EMNE.

本研究针对东地中海与近东（Eastern Mediterranean and Near East, EMNE；北纬33°–42°、东经21°–43°）区域内由79条树轮年表组成的首个大型网络展开描述与分析，旨在识别年树轮宽度指数中的季节性气候信号。研究采用相关分析与聚类分析方法处理树轮数据与网格化气候数据，以评估该网络中蕴含的气候信号，为气候场重建以及正式的气候代用资料与模型比对实验做准备。79条组合年表的时间跨度介于89年至990年之间。月相关分析与偏相关分析结果显示，该网络整体与5月、6月降水量呈普遍显著正相关，部分站点还与7月降水量存在正相关关系；其与冬季及春季（12月至次年4月）气温呈正相关，与5月至7月气温呈负相关。不过正如预期，这些整体规律存在站点间的差异。聚类分析结果表明，依据各站点与气候的关联特征，可将全部站点划分为3个群组。该区域的树轮年表在相当广阔的地理范围内展现出一致的季节性降水与气温信号特征。其主导信号为树木生长对5–6月降水量的正向响应。综合来看，本研究结果表明，该网络可用于构建东地中海与近东区域季尺度的降水与干旱历史气候场重建模型。