https://phys.org/news/2018-05-implications-enso.html

Mr. Lingjiang TAO, Dr. Chuan GAO and Professor Ronghua ZHANG, from the Institute of Oceanology, Chinese Academy of Sciences (IOCAS), studied targeted observation with respect to ENSO (El Niño-Southern Oscillation) events using an intermediate coupled model developed by IOCAS. Based on idealized OSSEs (observing system simulation experiments), they found that observing the central equatorial Pacific favors an improvement in prediction skill. "When removing the initial condition errors in the central equatorial Pacific, ENSO prediction errors can be reduced by 25 percent," explains the first author of the study, published in Advances in Atmospheric Sciences, Lingjiang TAO.

The team further examined the season-dependent sensitive areas for targeted observation, and presented a seasonally varying observational network that can better use the observations to give a more accurate prediction. "In addition to observing in the central equatorial Pacific and its north throughout the year, increasing observations in the eastern equatorial Pacific during April to October is crucially important, bringing about improvements in the prediction accuracy by 62 percent," the authors explain. In addition, the study found that implementing targeted observation can effectively weaken the so-called SPB (spring predictability barrier) phenomenon, and thus the prediction skill is improved significantly.