A severe drought occurred in East China (EC) from August to October 2019 against a background of long-term significant warming and caused widespread impacts on agriculture and society, emphasizing the urgent need to understand the mechanism responsible for this drought and its linkage to global warming. Our results show that the warm central equatorial Pacific (CEP) sea surface temperature (SST) and anthropogenic warming were possibly responsible for this drought event. The warm CEP SST anomaly resulted in an anomalous cyclone over the western North Pacific, where enhanced northerly winds in the northwestern sector led to decreased water vapor transport from the South China Sea and enhanced descending air motion, preventing local convection and favoring a precipitation deficiency over EC. Model simulations in the Community Earth System Model Large Ensemble Project confirmed the physical connection between the warm CEP SST anomaly and the drought in EC. The extremely warm CEP SST from August to October 2019, which was largely the result of natural internal variability, played a crucial role in the simultaneous severe drought in EC. The model simulations showed that anthropogenic warming has greatly increased the frequency of extreme droughts in EC. They indicated an approximate twofold increase in extremely low rainfall events, high temperature events, and concurrently dry and hot events analogous to the event in 2019. Therefore, the persistent severe drought over EC in 2019 can be attributed to the combined impacts of warm CEP SST and anthropogenic warming.

中文翻译：

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赤道中部太平洋暖温与人为变暖对2019年华东地区大旱的综合影响

在长期显着变暖的背景下，2019 年 8 月至 10 月华东地区（EC）发生严重干旱，对农业和社会造成广泛影响，强调迫切需要了解造成干旱的机制及其与全球的联系。变暖。我们的结果表明，温暖的中赤道太平洋 (CEP) 海面温度 (SST) 和人为变暖可能是造成这次干旱事件的原因。暖CEP海温异常导致西北太平洋上空出现异常气旋，西北地区偏北风增强导致南海水汽输送减少，下降气流增强，阻止了局地对流，有利于降水不足。欧共体。社区地球系统模型大型集合项目中的模型模拟证实了温暖的 CEP SST 异常与 EC 干旱之间的物理联系。2019 年 8 月至 10 月期间极端温暖的 CEP 海温主要是自然内部变率的结果，在欧共体同时发生的严重干旱中发挥了关键作用。模型模拟表明，人为变暖大大增加了欧共体极端干旱的频率。他们表明，与 2019 年类似的极低降雨事件、高温事件以及干热同时发生的事件大约增加了两倍。 因此，2019 年 EC 持续严重干旱可归因于暖 CEP SST 的综合影响和人为变暖。