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NERSC Initiative for Scientific Exploration (NISE) 2010 Awards

Decadal Predictability in CCSM4

Grant Branstator and Haiyan Teng, National Center for Atmospheric Research

Associated NERSC Project: Climate Change Simulations with CCSM: Moderate and High Resolution Studies (mp9), Principal Investigator: Warren Washington, National Center for Atmospheric Research

NISE Award: 1,600,000 Hours
Award Date: April 2010

We propose to estimate the initial-value decadal predictability in CCSM4 using a 40-member ensemble run with each of two perturbed atmospheric initial condition strategies. The runs will be integrated from year 2005 to 2025 under the IPCC RCP4.5 scenario external forcing. We have done similar experiments using CCSM3 and now plan to examine whether and how much the predictability property has changed in CCSM4.

The experiments will help to determine to what extent the ocean initial states can contribute to predictive skills on the decadal time scale. Whether there is initial-value decadal predictability must be addressed before the climate modeling community carries out decadal prediction experiments using initialized ocean observations.