EPIC2001 and the Coupled Ocean–Atmosphere System of the Tropical East Pacific

Abstract

Coupled global ocean?atmosphere models currently do a poor job of predicting conditions in the tropical east Pacific, and have a particularly hard time reproducing the annual cycle in this region. This poor performance is probably due to the sensitivity of the east Pacific to the inadequate representation of certain physical processes in the modeled ocean and atmosphere. The representations of deep cumulus convection, ocean mixing, and stratus region energetics are known to be problematic in such models. The U.S. Climate Variability and Predictability (CLIVAR) program sponsored the field experiment East Pacific Investigation of Climate Processes in the Coupled Ocean?Atmosphere System 2001 (EPIC2001), which has the goal of providing the observational basis needed to improve the representation of certain key physical processes in models. In addition to physical processes, EPIC2001 research is directed toward a better understanding and simulation of the effects of short-term variability in the east Pacific on climate. This variability is particularly important in the region because conditions in the intertropical convergence zone are highly variable on daily to intraseasonal time scales. The effects of such variability rectify strongly onto climate time scales in this region.