A review of the predictability and prediction of ENSO

Abstract

Abstract. A hierarchy of E1 Nifio-Southern Oscillation (ENSO) prediction schemes has been developed during the Tropical Ocean-Global Atmosphere (TOGA) program which includes statistical schemes and physical models. The statistical models are, in general, based on linear statistical techniques and can be classified into models which use atmospheric (sea level pressure or surface wind) or oceanic (sea surface temperature or a measure of upper ocean heat content) quantities or a combination of oceanic and atmospheric quantities as predictors. The physical models consist of coupled oceanatmosphere models of varying degrees of complexity, ranging from simplified coupled models of the "shallow water" type to coupled general circulation models. All models, statistical and physical, perform considerably better than the persistence forecast in predicting typical indices of ENSO on lead times of 6 to 12 months. The TOGA program can be regarded as a success from this perspective. However, despite the demonstrated predictability, little is known about ENSO predictability limits and the predictability of phenomena outside the tropical Pacific. Furthermore, the predictability of anomalous features known to be associated with ENSO (e.g., Indian monsoon and Sahel rainfall, southern African drought, and off-equatorial sea surface temperature) needs to be addressed in more detail. As well, the relative importance of different physical mechanisms (in the ocean or atmosphere) has yet to be established. A seasonal dependence in predictability is seen in many models, but the processes responsible for it are not fully understood, and its meaning is still a matter of scientific discussion. Likewise, a marked decadal variation in skill is observed, and the reasons for this are still under investigation. Finally, the different prediction models yield similar skills, although they are initialized quite differently. The reasons for these differences are also unclear.

Climate prediction for Brazil's Nordeste by empirical and numerical modeling methods

“…Prediction throughout the tropics on the basis of the empirical diagnostics and numerical modelling has been appraised in a sequence of reviews over the past decades (Hastenrath, 1985(Hastenrath, , 1986(Hastenrath, , 1990(Hastenrath, , 1995a(Hastenrath, ,b, 2002(Hastenrath, , 2006aBarnston et al, 1994Barnston et al, , 1999Palmer and Anderson, 1994;Carson, 1998;Latif et al, 1998, Anderson et al, 1999Nobre et al, 2006). Comparison of performance of the empirical and numerical modelling approaches is called for.…”

A note on the vertical scales of temperature and salinity and their signature in dynamic height in the western Pacific Ocean: Implications for data assimilation

“…Coupled ocean-atmosphere models that can approximate the oceanic state appear able to produce credible forecasts of the E1 Nifio-Southern Oscillation (ENSO) phenomenon (see Latif et al [1998] for a review). A fundamental part of the ENSO forecast problem is the initialization of the ocean component through data assimilation.…”

ENSO ensemble prediction and predictability for the past 148 years from 1856--2003.

“…On the decadal/interdecadal time scales, ENSO predictability has apparent decadal/interdecadal variations (e.g. Wang 1995; Kirtman and Schopf 1998;Latif et al 1998;Chen et al 2004;Tang et al 2008a). Tang et al…”

“…Significant progress has been made in ENSO prediction over the past few decades (e.g., Latif et al 1998;Shukla et. al.…”

“…for lead times of 6-12 months (Latif 1998;Kirtman et al 2002;Chen and Cane 2008). However, some important issues still remain unsolved such as the relationship between potential predictability and the actual prediction skill and the control factors of predictability.…”