Improving the long-lead predictability of El Niño using a novel forecasting scheme based on a dynamic components model

Petrova, Desislava; Koopman, Siem Jan; Ballester, Joan; Rodó, Xavier

doi:10.1007/s00382-016-3139-y

Cited by 30 publications

(47 citation statements)

References 73 publications

(137 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…El Niño‐Southern Oscillation (ENSO) [ Ballester et al ., ] is the dominant source of interannual variability worldwide and one of the most important modes of variability in the tropical Pacific, with far‐reaching influences on the whole climate system [ Jin , ,; Meinen and McPhaden , ; Wang , ; Brown and Fedorov , ; Ballester et al ., ; Petrova et al ., ]. The large amplitude of ENSO anomalies in the tropical Pacific is essentially explained by the strong coupling between the Walker circulation, the zonal gradient of sea surface temperature and the longitudinal tilt of the thermocline (i.e., the so‐called Bjerknes feedback [ Bjerknes , ; Wyrtki , ]).…”

Section: Introductionmentioning

confidence: 99%

Heat advection processes leading to El Niño events as depicted by an ensemble of ocean assimilation products

et al. 2016

Self Cite

View full text Add to dashboard Cite

The oscillatory nature of El Niño‐Southern Oscillation results from an intricate superposition of near‐equilibrium balances and out‐of‐phase disequilibrium processes between the ocean and the atmosphere. The main objective of the present work is to perform an exhaustive spatiotemporal analysis of the upper ocean heat budget in an ensemble of state‐of‐the‐art ocean assimilation products. We put specific emphasis on the ocean heat advection mechanisms, and their representation in individual ensemble members and in the different stages of the ENSO oscillation leading to EN events. Our analyses consistently show that the initial subsurface warming in the western equatorial Pacific is advected to the central Pacific by the equatorial undercurrent, which, together with the equatorward advection associated with anomalies in both the meridional temperature gradient and circulation at the level of the thermocline, explains the heat buildup in the central Pacific during the recharge phase. We also find that the recharge phase is characterized by an increase of meridional tilting of the thermocline, as well as a southward upper‐ocean cross‐equatorial mass transport resulting from Ekman‐induced anomalous vertical motion in the off‐equatorial regions. Although differences between data sets are generally small, and anomalies tend to have the same sign, the differences in the magnitude of the meridional term are seen to be key for explaining the different propagation speed of the subsurface warming tendency along the thermocline. The only exception is GECCO, which does not produce the patterns of meridional surface Ekman divergence (subsurface Sverdrup convergence) in the western and central equatorial Pacific.

show abstract

Section: Introductionmentioning

confidence: 99%

Heat advection processes leading to El Niño events as depicted by an ensemble of ocean assimilation products

et al. 2016

Self Cite

View full text Add to dashboard Cite

show abstract

“…Forecasts issued in spring or before are still generally unable to foresee whether an EN or a LN event will occur at the end of the year, the so-called spring barrier1516. Although recent advances suggest that it is indeed possible to overcome this predictability limit, either with intermediate6, purely dynamical7 or purely statistical17 models, the value of a real-time operational scheme derived from these results remains to be fully accomplished.…”

mentioning

confidence: 99%

Sensitivity of El Niño intensity and timing to preceding subsurface heat magnitude

Ballester

Petrova

Bordoni

et al. 2016

Sci Rep

Self Cite

View full text Add to dashboard Cite

Despite extensive ongoing efforts on improving the long-term prediction of El Niño-Southern Oscillation, the predictability in state-of-the-art operational schemes remains limited by factors such as the spring barrier and the influence of atmospheric winds. Recent research suggests that the 2014/15 El Niño (EN) event was stalled as a result of an unusually strong basin-wide easterly wind burst in June, which led to the discharge of a large fraction of the subsurface ocean heat. Here we use observational records and numerical experiments to explore the sensitivity of EN to the magnitude of the heat buildup occurring in the ocean subsurface 21 months in advance. Our simulations suggest that a large increase in heat content during this phase can lead to basin-wide uniform warm conditions in the equatorial Pacific the winter before the occurrence of a very strong EN event. In our model configuration, the system compensates any initial decrease in heat content and naturally evolves towards a new recharge, resulting in a delay of up to one year in the occurrence of an EN event. Both scenarios substantiate the non-linear dependency between the intensity of the subsurface heat buildup and the magnitude and timing of subsequent EN episodes.

show abstract

“…A structural timeseries model, which uses subsurface ocean temperature, wind stress, and sea surface temperature as predictor variables, was used to forecast the Niño3•4 index in 2016. 34 We chose this ENSO forecast model based on its ability to predict El Niño events in the past ( figure 2C). The model is comparable in performance to some of the most skilful dynamical ENSO models and generally performs better than other statistical schemes in terms of common skill metrics such as the root mean square error.…”

Section: Enso Forecast Modelmentioning

confidence: 99%

Climate services for health: predicting the evolution of the 2016 dengue season in Machala, Ecuador

Lowe

Stewart-Ibarra

Petrova

et al. 2017

The Lancet Planetary Health

Self Cite

110

112

View full text Add to dashboard Cite

show abstract

Improving the long-lead predictability of El Niño using a novel forecasting scheme based on a dynamic components model

Cited by 30 publications

References 73 publications

Heat advection processes leading to El Niño events as depicted by an ensemble of ocean assimilation products

Heat advection processes leading to El Niño events as depicted by an ensemble of ocean assimilation products

Sensitivity of El Niño intensity and timing to preceding subsurface heat magnitude

Climate services for health: predicting the evolution of the 2016 dengue season in Machala, Ecuador

Contact Info

Product

Resources

About