Weakening of annual temperature cycle over the Tibetan Plateau since the 1870s.
Weakening of annual temperature cycle over the Tibetan Plateau since the 1870s.
复制标题
1870年代以来青藏高原年气温循环减弱
DOI：
10.1038/ncomms14008
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发表时间：
2017-01-17
影响因子：
16.6
通讯作者：
Luterbacher J
中科院分区：
文献类型：
--
作者：
Duan J;Esper J;Büntgen U;Li L;Xoplaki E;Zhang H;Wang L;Fang Y;Luterbacher J
热带以外地区地表气温的年循环是地球气候系统的重要组成部分。在过去几十年中，在一些区域观察到这种模式的振幅减小。虽然归因于人为强迫，但仍不清楚年周期的抑制何时开始。本文利用青藏高原海拔4,000米以上地区的树木年轮宽度和最大晚材密度的残差序列，重建了近三个世纪以来的温度季节性变化。新的代用证据表明，青藏高原夏季到冬季温差的减少发生在19世纪70年代。我们的研究结果意味着，人为强迫对温度季节性的影响可能已经开始在世纪后期，未来的人类影响可能会进一步削弱年温度循环，随后对生态系统功能和生产力的影响。近几十年来，人们观察到青藏高原的年温度循环减弱，但长期背景仍然未知。在这里，作者根据树木年轮宽度和最大晚材密度重建了300年的温度记录，这表明早在19世纪70年代就开始减弱。
The annual cycle of extra-tropical surface air temperature is an important component of the Earth's climate system. Over the past decades, a reduced amplitude of this mode has been observed in some regions. Although attributed to anthropogenic forcing, it remains unclear when dampening of the annual cycle started. Here we use a residual series of tree-ring width and maximum latewood density from the Tibetan Plateau >4,000 m asl to reconstruct changes in temperature seasonality over the past three centuries. The new proxy evidence suggests that the onset of a decrease in summer-to-winter temperature difference over the Tibetan Plateau occurred in the 1870s. Our results imply that the influence of anthropogenic forcing on temperature seasonality might have started in the late nineteenth century, and that future human influence may further contribute to a weakening of the annual temperature cycle, with subsequent effects on ecosystem functioning and productivity. Weakening of the Tibetan Plateau's annual temperature cycle has been observed in recent decades, yet the long-term context remains unknown. Here, the authors reconstruct a 300-year temperature record from tree-ring width and maximum latewood density, which indicates the onset of weakening as early as the 1870s.