Coupled Variability and Predictability in a Stochastic Climate Model of the Tropical Atlantic Academic Article uri icon

abstract

  • Abstract The coupled variability and predictability of the tropical Atlantic oceanatmosphere system were analyzed within the framework of a linear stochastic climate model. Despite the existence of a meridional dipole as the leading mode, tropical Atlantic variability (TAV) is dominated by equatorial features and the subtropical variability is largely uncorrelated between the northern and southern Atlantic. This suggests that atmospheric stochastic forcing plays a dominant role in defining the spatial patterns of TAV, whereas the active airsea feedbacks mainly enhance variability at interannual and decadal time scales, causing the spectra distinctive from the red spectrum. Under the stochastic forcing, the useful predictive skill for sea surface temperature measured by normalized error variance is limited to 2 months on average, which is 1 month longer than the predictive skill of damped persistence, indicating that the contribution of ocean dynamics and airsea feedbacks is moderate in the tropical Atlantic. To achieve maximum predictability, processes such as ocean dynamics, thermodynamical and dynamical airsea feedbacks, and the delicate modemode interactions should be correctly resolved in the coupled models. Therefore, predicting TAV poses more challenge than predicting El Nio in the tropical Pacific.

published proceedings

  • JOURNAL OF CLIMATE

author list (cited authors)

  • Wang, F., & Chang, P.

citation count

  • 10

complete list of authors

  • Wang, Faming||Chang, Ping

publication date

  • December 2008