Geng Tao, Cai Wenju, Jia Fan, Wu Lixin
Laoshan Laboratory, Qingdao, China.
Frontiers Science Center for Deep Ocean Multispheres and Earth System (FDOMES) and Key Laboratory of Physical Oceanography, Ocean University of China, Qingdao, China.
Nat Commun. 2024 Jul 10;15(1):5810. doi: 10.1038/s41467-024-50156-9.
Under transient greenhouse warming, El Niño-Southern Oscillation (ENSO) is projected to increase pre-2100, accompanied by an easier establishment of atmospheric convection in the equatorial eastern Pacific, where sea surface temperature (SST) warms faster than surrounding regions. After 2100, how ENSO variability may change remains unknown. Here we find that under a high emission scenario, ENSO variability post-2100 reverses from the initial increase to an amplitude far smaller than that of the 20 century. The fast eastern warming persists and shrinks the equatorial Pacific non-convective area, such that establishing convection in the non-convective area, as during an El Niño, requires smaller convective anomaly, inducing weaker wind anomalies leading to reduced ENSO SST variability. The nonlinear ENSO response is thus a symptom of the persistent El Niño-like warming pattern. Therefore, the oscillatory ENSO impact could be replaced by that from the permanent El Niño-like mean condition with cumulative influences on affected regions.
在短暂的温室变暖情况下，预计到2100年前厄尔尼诺 - 南方涛动（ENSO）会增强，同时赤道东太平洋的大气对流更容易形成，该区域海面温度（SST）的升温速度比周边地区更快。2100年之后，ENSO变率如何变化仍然未知。在此我们发现，在高排放情景下，2100年后ENSO变率从最初的增强转变为幅度远小于20世纪的情况。赤道东太平洋快速变暖的态势持续存在，使得赤道太平洋非对流区域缩小，以至于在非对流区域形成对流（如在厄尔尼诺期间那样）所需的对流异常变小，导致风异常减弱，进而使ENSO海温变率降低。因此，ENSO的非线性响应是持续的类厄尔尼诺变暖模式的一种表现。所以，ENSO的振荡影响可能会被来自类似厄尔尼诺的永久性平均状态的影响所取代，并对受影响地区产生累积影响。
