NOAA/WDS Paleoclimatology - Touchan - Göller Update - JUEX - ITRDB TUR073

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.

本研究对东地中海与近东（Eastern Mediterranean and Near East, EMNE；33°N–42°N，21°E–43°E）地区首个包含79条树轮年表的大型网络展开描述与分析，以识别年际轮宽指数中的季节性气候信号。本研究通过对树轮数据与网格化气候数据开展相关分析与聚类分析，以评估该网络所蕴含的气候信号，为后续气候场重建以及标准化代用资料与模型对比试验奠定基础。79条树轮年表的组合时长跨度为89至990年。月度相关分析与偏相关分析结果显示，该网络普遍与5月、6月（部分站点与7月）降水量呈显著正相关，与冬季及春季（12月至次年4月）气温呈正相关，而与5月至7月气温呈负相关；不过正如预期，各站点间存在与这一总体规律不符的例外情况。聚类分析结果表明，依据站点与气候的关联特征，可将所有站点划分为3个组别。EMNE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，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，该树轮网络可用于构建EMNE地区针对特定季节的降水与干旱历史气候场重建方案。