NOAA/WDS Paleoclimatology - Tibetan Plateau 440 Year August-September Temperature Reconstructions

To assess the recent warming on the Tibetan Plateau (TP), some tree-ring-based temperature reconstructions have been performed. However, most of the previous studies focused on the local or regional scale. In this study, we analyzed the recent variability of August-September temperature using observations from 79 TP meteorological stations, and the observed records were extended back to 1,572 based on a tree-ring maximum density network comprising 17 sites. Moreover, the future August-September temperature scenarios on the TP are also presented using the ensemble mean of five regional climate models. The tree-ring maximum late-wood density network shows good capacity to reconstruct the August-September temperature variability at the spatial scale of the whole TP (i.e., 79-station average; r1951-2014 = 0.80, P < 0.01). The reconstruction suggests that the instrumental epoch is the warmest interval of August-September over the past four and a half centuries on the TP, and the decadal-scale August-September warming since the 1960s is unprecedented. The ensemble simulation of five regional climate models indicates that persistent August-September warming will occur on the TP in the future. The magnitude of August-September warming is approximately 1.56 ± 0.30C and 3.02 ± 0.29C over the period 2006-2049 under the Representative Concentration Pathways (RCPs) 4.5 and P8.5 scenarios, respectively. These results imply a further ecological and environmental change on the TP linked to the persistent warming in the future.

为评估青藏高原（Tibetan Plateau, TP）近期的变暖趋势，已有多项基于树木年轮的温度重建研究。然而，既往多数研究仅聚焦于局地或区域尺度。本研究利用青藏高原79个气象站点的观测数据，分析了8-9月温度的近期变化特征，并基于包含17个采样点的树木年轮最大密度网络，将观测序列延长至公元1572年。此外，本研究还基于5个区域气候模式的集合平均结果，给出了青藏高原8-9月温度的未来情景。该树木年轮晚材最大密度网络在全青藏高原空间尺度（即79站平均）上展现出良好的8-9月温度重建能力（1951-2014年相关系数r=0.80，P<0.01）。重建结果显示，仪器观测时期是过去450余年来青藏高原8-9月温度最高的时段，而1960年代以来的年代际尺度8-9月增温趋势前所未有。5个区域气候模式的集合模拟结果表明，未来青藏高原将持续出现8-9月增温。在典型浓度路径（Representative Concentration Pathways, RCPs）4.5和8.5情景下，2006-2049年期间的8-9月增温幅度分别约为1.56±0.30℃和3.02±0.29℃。上述结果预示，未来青藏高原将伴随持续增温出现进一步的生态与环境变化。