FORTE 2.0: A fast, parallel and flexible coupled climate model

Abstract

p>FORTE 2.0 is an intermediate-resolution coupled atmosphere-ocean general circulation model (AOGCM) consisting of the Intermediate General Circulation Model 4 (IGCM4), a T42 spectral atmosphere with 35 span classCombining double low line inline-formula > ilayers, coupled to Modular Ocean Model - Array (MOMA), a 2 span classCombining double low line inline-formula span classCombining double low line inline-formula 2 span classCombining double low line inline-formula ocean with 15 span classCombining double low line inline-formula layer depth levels. Sea ice is represented by a simple flux barrier. Both the atmosphere and ocean components are coded in Fortran. It is capable of producing a stable climate for long integrations without the need for flux adjustments. One flexibility afforded by the IGCM4 atmosphere is the ability to configure the atmosphere with either 35 span classCombining double low line inline-formula layers (troposphere and stratosphere) or 20 span classCombining double low line inline-formula layers (troposphere only). This enables experimental designs for exploring the roles of the troposphere and stratosphere, and the faster integration of the 20 span classCombining double low line inline-formula > ilayer configuration enables longer duration studies on modest hardware. A description of FORTE 2.0 is given, followed by the analysis of two 2000-year control integrations, one using the 35 span classCombining double low line inline-formula of IGCM4 and one using the 20 span classCombining double low line inline-formula > iconfiguration. /p>.