During El Niño events, increased precipitation occurs over the equatorial central eastern Pacific, corresponding to enhanced convective heating that modulates global climate by exciting atmospheric teleconnections. These precipitation anomalies are projected to shift and extend eastward in response to global warming. We show that this predicted change is caused by narrowing of the meridional span of the underlying El Niño-related sea surface temperature (SST) anomalies that leads to intensification of the meridional gradient of the SST anomalies, strengthening boundary-layer moisture convergence over the equatorial eastern Pacific, and enhancing local positive precipitation anomalies. The eastward shift and extension of these anomalies also intensify and extend eastward negative precipitation anomalies over the tropical western North Pacific, by strengthening equatorward advection of low mean moist enthalpy. Changes in El Niño-induced tropical precipitation anomalies suggest that, under global warming, El Niño events decay faster after their peak phase, thus shortening their duration.

中文翻译：

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全球变暖下ENSO引起的热带降水异常的东移和扩展。

在厄尔尼诺事件期间，赤道中东部太平洋上空降水增加，这与对流加热增强有关，对流加热通过激发大气遥相关来调节全球气候。这些降水异常预计将随着全球变暖向东移动和扩展。我们表明，这种预测的变化是由于与厄尔尼诺现象有关的海面温度（SST）异常的子午跨度变窄而导致，这导致了SST异常子午线梯度的加剧，加强了赤道边界层的水分汇聚东太平洋，并增强了局部正降水异常。这些异常的东移和扩展也加剧和扩展了北太平洋热带西部的负降水异常。通过加强低平均湿焓的赤道对流。厄尔尼诺现象引起的热带降水异常的变化表明，在全球变暖的情况下，厄尔尼诺现象在高峰期后衰减更快，从而缩短了持续时间。