The similarity between the seasonal Predictability and Persistence
Barrier of ENSO phenomenon
Abstract
The seasonal Predictability Barrier (PRB) and Persistence Barrier (PEB)
in the El Niño-Southern Oscillation (ENSO) phenomenon are of recent
interest, yet the distinction between the PRB in observations and PEB in
ensemble forecast models remains unexplored. Using observational and
North American Multimodel Ensemble data since the 1980s, we examined the
seasonal PRB and PEB, focusing on intensity, timing, decadal variations,
and spatial patterns. Although the intensity of the ENSO spring PRB in
dynamic models is notably lower than the spring PEB intensity, the
temporal variations, spatial patterns and barrier timing of the PRB and
PEB are similar. The chaotic nature of ENSO systems exhibits comparable
decadal variations and spatial patterns to the seasonal PEB and PRB,
suggesting potential control by chaotic behavior for both seasonal PRB
and PEB. Hence, the seasonal PEB of ENSO can still provide useful
benchmarks for the predictability study of ENSO in dynamic models.