One of the main modes of sea surface temperature variability in the Tropical Atlantic is the Atlantic Equatorial Mode or Atlantic Niño. The region of largest interannual variability, where the Atlantic Cold Tongue forms, is also a region of consistent biases in climate models. In this study, we investigate the interannual variability of the Tropical Atlantic and its changes in the recent decades in terms of the Bjerknes Feedback Index (\(\hbox {I}_{BJ}\)) in a set of seven ocean reanalyses for the periods 1980–1999 and 2000–2010. Differences were observed among the reanalyses regarding their representation of each term of the Bjerknes Feedback, particularly regarding zonal surface currents, leading to differences in dynamical damping and the zonal advective feedback. However, a consistent negative index (damped) is observed in all reanalysis, with the thermocline feedback being the dominant positive term and thermal damping the dominant negative term. Warming trends are observed in sea surface temperatures in the cold tongue region in all reanalyses, as well as a decrease in interannual variability. These in turn are associated with a weakening in the Bjerknes Feedback in the early XXI century, indicated by a stronger and negative index. This results from a stronger thermal damping and weaker thermocline feedback, associated with a weaker response of equatorial zonal thermocline slope to equatorial zonal wind stress. Despite the spread among the reanalysis, the results obtained are consistent with previous studies.

热带大西洋海表温度变化的主要模式之一是大西洋赤道模式或大西洋Niño。大西洋冷舌形成的年际变化最大的区域，也是气候模型中持续偏见的区域。在这项研究中，我们根据Bjerknes反馈指数（\（\ hbox {I} _ {BJ} \），调查了近几十年来热带大西洋的年际变化及其变化），对1980-1999年和2000-2010年进行了七次海洋再分析。在重新分析中观察到关于Bjerknes反馈每个项的表示形式存在差异，特别是在区域表面电流方面存在差异，从而导致动力阻尼和区域对流反馈的差异。但是，在所有重新分析中均观察到一致的负指数（阻尼），其中温跃层反馈为主要正项，而热阻尼为主要负项。在所有重新分析中，在冷舌地区的海表温度均观测到变暖趋势，并且年际变化也有所减少。这些反过来又与二十一世纪初的Bjerknes反馈减弱有关，这表现为较强的负指数。这是由于较强的热阻尼和较弱的热跃层反馈所致，同时伴有赤道纬向热跃层斜率对赤道纬向风应力的响应较弱。尽管重新分析之间存在分歧，但获得的结果与以前的研究一致。