A 400-year record of hydroclimate variability and local ENSO history in northern Southeast Asia inferred from tree-ring δ18O
A 400-year record of hydroclimate variability and local ENSO history in northern Southeast Asia inferred from tree-ring δ18O
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DOI：
10.1016/j.palaeo.2013.06.025
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发表时间：
2013-09
期刊：
影响因子：
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通讯作者：
Chenxi Xu;M. Sano;T. Nakatsuka
中科院分区：
文献类型：
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作者：
Chenxi Xu;M. Sano;T. Nakatsuka
本文根据对生长在老挝北方的7棵福建柏（Fokienia hodginsitrees）的年轮纤维素δ 18 O的测定，给出了1588-2002年的年轮纤维素δ 18 O年表。气象资料的响应函数分析表明，该氧同位素年代学与季风季节降水量、湄公河水位和Palmer干旱严重度指数（PDSI）呈显著负相关。我们重建的季风季节PDSI，占PDSI方差的41.5%，表明多雨期发生在AD 1660-1695和AD 1705-1790，主要干旱期是AD 1630-1660，AD 1900-1940和AD 1954-2002。在过去的200年里，季风季节的湿度有下降的趋势。季风活动的减少也可以在喜马拉雅山、西藏高原和东南亚的各种树木年轮氧同位素记录中看到。热带太平洋和印度洋海面温度的上升可能是亚洲夏季风减少的原因。通过对老挝北方和越南的厄尔尼诺-南方涛动（ENSO）敏感指标的组合，我们能够重建年度多变量ENSO指数（MEI）和当地ENSO事件历史，从而提高我们对ENSO长期变化及其对东南亚影响的理解。
We present here a chronology of tree ring cellulose δ18O for the period 1588–2002 based on individual measurements of sevenFokienia hodginsiitrees growing in northern Laos. Response function analysis of meteorological data revealed that this oxygen isotope chronology has a significant negative correlation with monsoon season precipitation, the water level of the Mekong River, and the Palmer drought severity index (PDSI). Our reconstructed monsoon season PDSI, which accounts for 41.5% of PDSI variance, showed that wetter phases occurred during the periods AD 1660–1695 and AD 1705–1790, that the main drier periods were AD 1630–1660, AD 1900–1940, and AD 1954–2002, and that there has been a trend of decreasing moisture during the monsoon season over the last 200 years. A reduction in monsoon activity can also be seen in various tree ring oxygen isotope records from the Himalaya, Tibet Plateau, and Southeast Asia. Rising sea surface temperatures over the tropical Pacific and Indian Ocean could be responsible for this reduction in the Asian summer monsoon. By combining proxies sensitive to the El Niño–Southern Oscillation (ENSO) in northern Laos and Vietnam, we were able to reconstruct the annual multivariate ENSO index (MEI) and local ENSO event history, and so improve our understanding of long-term variations in ENSO and its influences on Southeast Asia.