The low-resolution CCSM2 revisited: new adjustments and a present-day control run

M. Prange (1)

1 DFG Research Center Ocean Margins and Department of Geosciences

The low-resolution (T31) version of the Community Climate System Model CCSM2.0.1 is revisited and adjusted by deepening the Greenland-Scotland ridge, changing oceanic mixing parameters, and applying a regional freshwater flux adjustment at high northern latitudes. The main purpose of these adjustments is to maintain a robust Atlantic meridional overturning circulation which collapses in the original model release. The paper describes the present-day control run of the adjusted model which is brought into climatic equilibrium by applying a deep-ocean acceleration technique. The accelerated integration is extended by a 100-year synchronous phase. The simulated meridional overturning circulation has a maximum of 14×10⁶ m³ s^?1 in the North Atlantic. Most shortcomings found in the control run are identified as "typical problems" in global climate modelling. Given its good simulation skills and its relatively low resource demands, the adjusted low-resolution version of CCSM2.0.1 appears to be a reasonable alternative to the latest low-resolution Community Climate System Model release (CCSM3.0) if runtime is a critical factor.

Domaines: Océan, Atmosphère

M. Prange. The low-resolution CCSM2 revisited: new adjustments and a present-day control run. Ocean Science Discussions, 2006, 3 (4), pp.1293-1348. ⟨hal-00298413⟩