Weisheimer Antje, Balmaseda Magdalena A, Stockdale Tim N, Mayer Michael, Sharmila S, Hendon Harry, Alves Oscar
European Centre for Medium-Range Weather Forecasts (ECMWF) Reading UK.
University of Oxford Department of Physics National Centre for Atmospheric Science (NCAS) Oxford UK.
Geophys Res Lett. 2022 May 28;49(10):e2022GL097885. doi: 10.1029/2022GL097885. Epub 2022 May 18.
In order to explore temporal changes of predictability of El Niño Southern Oscillation (ENSO), a novel set of global biennial climate reforecasts for the historical period 1901-2010 has been generated using a modern initialized coupled forecasting system. We find distinct periods of enhanced long-range skill at the beginning and at the end of the twentieth century, and an extended multi-decadal epoch of reduced skill during the 1930s-1950s. Once the forecast skill extends beyond the first spring barrier, the predictability limit is much enhanced and our results provide support for the feasibility of skillful ENSO forecasts up to 18 months. Changes in the mean state, variability (amplitude), persistence, seasonal cycle and predictability suggest that multi-decadal variations in the dynamical characteristics of ENSO rather than the data coverage and quality of the observations have primarily driven the reported non-monotonic skill modulations.
为了探究厄尔尼诺-南方涛动（ENSO）可预测性的时间变化，利用一个现代初始化耦合预测系统生成了一组新的1901 - 2010年历史时期全球两年期气候再预测数据。我们发现，在20世纪初和20世纪末存在明显的长程技能增强期，而在20世纪30年代至50年代技能降低的多十年时期有所延长。一旦预测技能突破首个春季障碍，可预测性极限会大幅增强，我们的结果为长达18个月的ENSO技能预测的可行性提供了支持。平均状态、变率（振幅）、持续性、季节循环和可预测性的变化表明，ENSO动力特征的多十年变化而非观测数据的覆盖范围和质量是所报告的非单调技能调制的主要驱动因素。
