Tian Qi, Yu Jin-Yi, Nnamchi Hyacinth C, Li Tim, Li Jianping, Li Xichen, Ding Ruiqiang
State Key Laboratory of Earth Surface Processes and Disaster Risk Reduction (ESPDRR), Beijing Normal University, Beijing, China.
Key Laboratory of Environmental Change and Natural Disasters of Chinese Ministry of Education, Beijing Normal University, Beijing, China.
Nat Commun. 2025 Jul 1;16(1):5884. doi: 10.1038/s41467-025-61130-4.
The El Niño-Southern Oscillation (ENSO) is known to respond to tropical Atlantic (TA) sea surface temperature (SST) forcing. However, the response time of ENSO to the TA SST forcing is not stationary but varies over decades, the reasons for which remain poorly understood. Here we show that decadal changes in ENSO's response time to TA SST forcing are primarily influenced by the south-north shift of the dominant mode of TA SST variability itself. Before the mid-1980s, the southward-shifted TA mode prolongs the response time to ~20 months through an eastward-propagating mid-latitude teleconnection. In contrast, when the TA mode shifts northward after the mid-1980s, the response time decreases to 6-9 months via a faster westward-propagating subtropical teleconnection. Our findings underscore the importance of considering the meridional shift of the TA mode when understanding the impacts of the TA SST variability on ENSO, which has profound implications for ENSO forecasting.
众所周知，厄尔尼诺-南方涛动（ENSO）会对热带大西洋（TA）海表温度（SST）强迫做出响应。然而，ENSO对TA海表温度强迫的响应时间并非固定不变，而是在数十年间有所变化，其原因仍知之甚少。在此我们表明，ENSO对TA海表温度强迫的响应时间的年代际变化主要受TA海表温度变率主导模式的南北移动影响。在20世纪80年代中期之前，向南移动的TA模式通过向东传播的中纬度遥相关将响应时间延长至约20个月。相比之下，当TA模式在20世纪80年代中期之后向北移动时，响应时间通过更快的向西传播的副热带遥相关降至6 - 9个月。我们的研究结果强调了在理解TA海表温度变率对ENSO的影响时考虑TA模式经向移动的重要性，这对ENSO预测具有深远意义。
