As a strong climate element on interannual scales, the El Nino-Southern Oscillation (ENSO) is a major component of global weather and climate change, and it is also closely related to the interannual atmospheric angular momentum (AAM) and length-of-day changes (ΔLOD). Here, we reprocess and compare the interannual variations of AAM, ΔLOD with ENSO indices, with AAM mass and motion terms calculated over land separately from those over the ocean. Three oscillatory components (at ~ 6, ~ 7, ~ 8 years), due to angular momentum changes in Earth's interior, are removed to obtain the interannual ΔLOD solely related to climatic variations. Our results show that the AAM motion term over the ocean contributes the most to interannual ΔLOD, and that the oceanic AAM has larger variability than that over land, especially during the periods of strong ENSO events. After subtracting contributions associated with interior processes, the interannual ΔLOD anomalies corresponding to extreme ENSO events (1982–1983 ~ 0.43, 1997–1998 ~ 0.36, 2015–2016 ~ 0.42 ms) are about half as strong as those found in previous studies (~ 0.91, ~ 0.76, ~ 0.81 ms). Furthermore, we detect an intermediate La Nina event that occurred from August 2020 to May 2021, forcing the interannual ΔLOD to a minimum value of approximately -0.21 ms.

厄尔尼诺-南方涛动（ENSO）作为年际尺度上的强气候要素，是全球天气气候变化的重要组成部分，与年际大气角动量（AAM）和日长密切相关。变化（ΔLOD）。在这里，我们重新处理并比较了 AAM、ΔLOD 与 ENSO 指数的年际变化，其中 AAM 质量和运动项在陆地上的计算与海洋上的分别计算。由于地球内部的角动量变化，三个振荡分量（约 6 年、约 7 年、约 8 年）被移除，以获得仅与气候变化相关的年际 ΔLOD。我们的研究结果表明，海洋上空的 AAM 运动项对年际 ΔLOD 的贡献最大，并且海洋 AAM 的变化比陆地上的变化更大，特别是在强烈的ENSO事件期间。减去与内部过程相关的贡献后，与极端 ENSO 事件（1982-1983 ~ 0.43、1997-1998 ~ 0.36、2015-2016 ~ 0.42 ms）相对应的年际 ΔLOD 异常大约是先前研究中发现的异常强度的一半（~ 0.91，~ 0.76，~ 0.81 毫秒）。此外，我们检测到 2020 年 8 月至 2021 年 5 月发生的中间拉尼娜事件，迫使年际 ΔLOD 达到约 -0.21 毫秒的最小值。