Deng Jiechun, Dai Aiguo
Key Laboratory of Meteorological Disaster, Ministry of Education (KLME)/Joint International Research Laboratory of Climate and Environmental Change (ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD), Nanjing University of Information Science and Technology, Nanjing 210044, China.
Department of Atmospheric and Environmental Sciences, University at Albany, State University of New York, Albany, NY 12222, USA.
Sci Adv. 2024 Mar 29;10(13):eadk3990. doi: 10.1126/sciadv.adk3990.
El Niño-Southern Oscillation (ENSO) over the tropical Pacific can affect Arctic climate, but whether it can be influenced by the Arctic is unclear. Using model simulations, we show that Arctic sea ice-air interactions weaken ENSO by about 12 to 17%. The northern North Pacific Ocean warms due to increased absorption of solar radiation under such interactions. The warming excites an anomalous tropospheric Rossby wave propagating equatorward into the tropical Pacific to strengthen cross-equator winds and deepen the thermocline. These mean changes dampen ENSO amplitude via weakened thermocline and zonal advective feedbacks. Observed historical changes from 1921-1960 (with strong sea ice-air interactions) to 1971-2000 (with weak interactions) are qualitatively consistent with the model results. Our findings suggest that Arctic sea ice-air interactions affect both the mean state and variability in the tropical Pacific, and imply increased ENSO amplitude as Arctic sea ice and its interactions with the atmosphere diminish under anthropogenic warming.
热带太平洋上空的厄尔尼诺-南方涛动（ENSO）会影响北极气候，但它是否会受到北极的影响尚不清楚。通过模型模拟，我们发现北极海冰-空气相互作用使ENSO减弱了约12%至17%。在这种相互作用下，北太平洋北部由于太阳辐射吸收增加而变暖。这种变暖激发了异常的对流层罗斯贝波向赤道方向传播到热带太平洋，从而加强了跨赤道风并加深了温跃层。这些平均变化通过减弱温跃层和纬向平流反馈来抑制ENSO的振幅。1921年至1960年（海冰-空气相互作用强烈）到1971年至2000年（相互作用较弱）的观测历史变化在定性上与模型结果一致。我们的研究结果表明，北极海冰-空气相互作用会影响热带太平洋的平均状态和变率，并意味着随着北极海冰及其与大气的相互作用在人为变暖下减少，ENSO的振幅会增加。
