Long-term coupled variability of temperature and precipitation in eastern China and the underlying mechanisms
Long-term coupled variability of temperature and precipitation in eastern China and the underlying mechanisms
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DOI：
10.1007/s00382-023-06963-9
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发表时间：
2023-10
期刊：
影响因子：
4.6
通讯作者：
Yue Zhang;Wen Zhou;Xiaocheng Yu;Ye Tian;Ruhua Zhang
中科院分区：
文献类型：
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作者：
Yue Zhang;Wen Zhou;Xiaocheng Yu;Ye Tian;Ruhua Zhang
利用经验正交函数（EOF）分析了中国东部夏季气温和降水的耦合变率，以更好地理解和缓解复合干旱和热浪等极端事件的同时发生。结果表明：长江北部地区表现出强烈的增干趋势，长江南部地区表现出相反的增干趋势；第二张图显示了中国南方温度和降水的年代际振荡，在湿冷条件和干热条件之间交替。通过相关分析、复合分析和模型模拟揭示了这些主要模式的潜在机制。第一个模态与低层大气中的太平洋-日本负遥相关和对流层上层穿越欧亚大陆的静止罗斯比波列有关，这是受全球变暖和北大西洋西部海表温度异常的影响。第二个模态与北大西洋涛动（NAO）和太平洋年代际涛动（PDO）的交替活动期有关。NAO活跃期对中国东部夏季气候的影响显著，而PDO在NAO活跃期对中国东部夏季气候的影响相反。这些发现为中国东部地区更好地应对复合极端事件的长期规划和适应策略提供了有价值的启示。
This study investigates the coupled variability of temperature and precipitation in eastern China during summer using empirical orthogonal function (EOF) analysis to better understand and mitigate simultaneous occurrences of extreme events, such as compound droughts and heat waves. Two dominant modes are identified: the first exhibits a strong warming and drying trend in the region north of the Yangtze River, with the opposite occurring in the south; the second illustrates decadal oscillations in temperature and precipitation, alternating between cool-wet conditions and warm-dry conditions in southern China. The underlying mechanisms for these leading modes are revealed through correlation, composite analysis, and model simulations. The first mode is associated with a negative Pacific-Japan teleconnection in the lower atmosphere and a stationary Rossby wave train across Eurasia in the upper troposphere, which are influenced by global warming and sea surface temperature anomalies in the western North Atlantic. The second mode is linked to alternating active periods of the North Atlantic Oscillation (NAO) and Pacific Decadal Oscillation (PDO). The NAO exerts a significant influence on the summer climate in eastern China during its active phases, while the PDO shows an opposite effect when the NAO is less active. These findings provide valuable implications for long-term planning and adaptation strategies to better cope with compound extreme events in eastern China.