Skill of Real-Time Seasonal ENSO Model Predictions During 2002–11: Is Our Capability Increasing?

TLDR: In this article, real-time model predictions of ENSO conditions during the 2002-11 period are evaluated and compared to skill levels documented in studies of the 1990s, finding that decadal variations in the character of EnsO variability are a greater skill-determining factor than the steady but gradual trend toward improved ENSo prediction science and models.

Abstract: Real-time model predictions of ENSO conditions during the 2002–11 period are evaluated and compared to skill levels documented in studies of the 1990s. ENSO conditions are represented by the Nino- 3.4 SST index in the east-central tropical Pacific. The skills of 20 prediction models (12 dynamical, 8 statistical) are examined. Results indicate skills somewhat lower than those found for the less advanced models of the 1980s and 1990s. Using hindcasts spanning 1981–2011, this finding is explained by the relatively greater predictive challenge posed by the 2002–11 period and suggests that decadal variations in the character of ENSO variability are a greater skill-determining factor than the steady but gradual trend toward improved ENSO prediction science and models. After adjusting for the varying difficulty level, the skills of 2002–11 are slightly higher than those of earlier decades. Unlike earlier results, the average skill of dynamical models slightly, but statistically significantly, exceeds that of sta...