Summer Monsoon Variability in the Himalaya Over Recent Centuries
Summer Monsoon Variability in the Himalaya Over Recent Centuries
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DOI：
10.1007/978-3-030-29684-1_14
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发表时间：
2019
期刊：
影响因子：
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通讯作者：
M. Sano;Chenxi Xu;A. P. Dimri;R. Ramesh
中科院分区：
文献类型：
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作者：
M. Sano;Chenxi Xu;A. P. Dimri;R. Ramesh
利用树木年轮氧同位素记录研究了喜马拉雅山夏季风季节（6 - 9月）的水文气候变化。由于其与水文气候变量，包括降水，相对湿度和帕尔默干旱强度指数，树轮δ 18 O年代学从喜马拉雅山可以用来重建夏季风强度精确。一个区域年表来自五个地方年表跨越喜马拉雅山显示了显着的相关性与印度夏季降雨量数据。区域年表最值得注意的特征之一是过去180年来的干燥趋势，表明喜马拉雅地区的夏季风强度减弱。南亚地区陆-海热力梯度的下降似乎是夏季风减弱的原因。通过分析喜马拉雅地区带状分布的树木年轮数据之间的时空相关性，我们还探讨了可能的变化，在阿拉伯海和孟加拉湾起源的源水的相对贡献。
Hydroclimatic variations during the summer monsoon season (June–September) across the Himalaya are examined over the past several hundred years using tree-ring oxygen isotope records. Owing to their strong associations with hydroclimatic variables including precipitation, relative humidity, and the Palmer Drought Severity Index, tree-ring δ18O chronologies from the Himalaya can be used to reconstruct summer monsoon intensity precisely. A regional chronology derived from five local chronologies across the Himalaya shows a significant correlation with Indian summer rainfall data. One of the most noteworthy features of the regional chronology is a drying trend over the past 180 years, indicating that summer monsoon intensity in the Himalayan region has weakened. A declining land–ocean thermal gradient over South Asia seems to be responsible for the weakened summer monsoon. By analyzing spatio-temporal correlations between zonally distributed tree-ring data over the Himalaya, we also explore possible changes in the relative contributions of source water originating in the Arabian Sea and the Bay of Bengal.