研究人员在历史辐射作用力下，进行了配对集合模拟的耦合模型相互比较——一个具有自由发展的南太平洋海面温度，另一个具有受限于后续观测的南大洋南太平洋海温异常。研究用更强和更真实的云反馈揭示了观测到的南大洋冷却的全球影响，包括南极海冰扩张、热带太平洋东南部冷却、北移的哈德莱环流、阿留申低压减弱和北太平洋变暖。因此，研究结果表明，近几十年来，观测到的南大洋南太平洋海面温度下降可能对热带太平洋东部的较冷环境有所贡献。
据了解，自卫星时代开始以来，尽管全球变暖，但南太平洋海面温度(SSTs)已经降低。虽然之前的论文已经报道了，观测到的南大洋冷却对热带太平洋的影响很小，但是最近的研究已经表明，这种遥相关的效率是由高度依赖于模式的亚热带云反馈所介导的。
附：英文原文
Title: Global impacts of recent Southern Ocean cooling
Author: Kang, Sarah M., Yu, Yue, Deser, Clara, Zhang, Xiyue, Kang, In-Sik, Lee, Sun-Seon, Rodgers, Keith B., Ceppi, Paulo
Issue&Volume: 2023-7-17
Abstract: Since the beginning of the satellite era, Southern Ocean sea surface temperatures (SSTs) have cooled, despite global warming. While observed Southern Ocean cooling has previously been reported to have minimal impact on the tropical Pacific, the efficiency of this teleconnection has recently shown to be mediated by subtropical cloud feedbacks that are highly model-dependent. Here, we conduct a coupled model intercomparison of paired ensemble simulations under historical radiative forcing: one with freely evolving SSTs and the other with Southern Ocean SST anomalies constrained to follow observations. We reveal a global impact of observed Southern Ocean cooling in the model with stronger (and more realistic) cloud feedbacks, including Antarctic sea–ice expansion, southeastern tropical Pacific cooling, northward-shifted Hadley circulation, Aleutian low weakening, and North Pacific warming. Our results therefore suggest that observed Southern Ocean SST decrease might have contributed to cooler conditions in the eastern tropical Pacific in recent decades.
DOI: 10.1073/pnas.2300881120
Source: https://www.pnas.org/doi/10.1073/pnas.2300881120