AMO对中南半岛旱季极端高温频次年代际变化的影响及机制研究

中南半岛地处“一带一路”沿线，与中国经贸往来密切，近年来当地旱季极端高温频发，对生产生活危害极大。大西洋多年代际振荡（AMO）因其对大气环流和热带海温异常的调制作用，对北半球气候的年代际变化产生重要影响。项目前期工作表明，1951年以来，中南半岛旱季极端高温日的出现频次有两次年代际转折，且变化发生时间与AMO位相转变较为一致，但相关机理尚不清楚。因此，本项目拟针对两个科学问题开展研究：中南半岛旱季极端高温频次及其气候背景的年代际变化特征；AMO对中南半岛旱季极端高温频次年代际变化的影响。项目将以较长时间跨度的多源资料为基础，综合运用统计-动力诊断及数值模拟方法，研究AMO如何通过影响大气遥相关及热带海温异常等过程，调制中南半岛旱季极端高温频次的年代际变化，揭示其影响路径与机制。本项目的成功实施有助于加深理解自然变率对中南半岛极端气候年代际变化的调控作用，为当地年代际气候预测提供科学参考。

The Indochina Peninsula (ICP), located along the "Belt and Road", has close relationships of economy and trading with China. The heat extremes have occurred frequently over the ICP during the dry season in recent years, which threaten the local agricultural production and human life. The Atlantic Multidecadal Oscillation (AMO) has great impacts on the decadal variation of northern hemisphere climate via modulating the atmospheric circulations and the tropical sea surface temperature. Preliminary investigations have revealed that there have been two decadal variations on the extreme heat day frequency in the dry season over the ICP since 1951, with its changing time well consistent with the AMO phase transitions. However, the corresponding mechanisms have not yet been comprehensively revealed. Therefore, the current project would mainly concentrate on the following scientific issues: 1) the decadal variation characteristics of extreme heat day frequency in the dry season over the ICP and its relevant climatological backgrounds, 2) the specific modulations of the AMO on the decadal variation of extreme heat day frequency in the dry season over the ICP. In this project, based on multiple long-range datasets and approaches of statistics, dynamics and numerical simulations, the decadal variation of extreme heat day frequency in the dry season over the ICP would be investigated, as well as the corresponding modulations from the AMO via affecting the teleconnections and tropical sea surface temperature. Specific impacting pathways and mechanisms of the AMO on the decadal variation of extreme heat day frequency in the dry season over the ICP are to be revealed by the project. More comprehensive understanding of the natural variability modulations on the decadal variation of the local extremes would provide the decadal climate prediction over the ICP with scientific fundamentals.