Nobumasa KOMORI

CFES: Coupled Atmosphere–Ocean GCM for the Earth Simulator

About CFES


Figure: Monthly-mean fields in February of the 19th year from a global simulation using the high-resolution version of CFES. (From top to bottom) wind speed at 250-hPa height, precipitation, sea surface temperature, and current speed at 1500-m depth. [Click to enlarge the figures.]

CFES stands for Coupled atmosphere–ocean general circulation model (GCM) for the Earth Simulator (ES). It consists of AFES (Atmospheric GCM for the ES: Ohfuchi et al., 2004; Enomoto et al., 2008; Kuwano-Yoshida et al., 2010) as an atmospheric component including a land-surface process and OFES (Ocean GCM for the ES: Masumoto et al., 2004; Komori et al., 2005, 2012) as an oceanic component including a sea-ice process, and is designed to achieve efficient computational performance on the ES by using MPMD (multiple program multiple data) technique and fully parallelized coupling schemes (Takahashi et al., 2003). CFES and its component models have been developed and maintained by the Earth Simulator Center in collaboration with other sections (e.g., the Frontier Research Center for Global Change) of JAMSTEC.

So far, two settings of CFES have been integrated for numerical studies of atmosphere–ocean interaction. The high-resolution version, sometimes called “CFES standard”, has the resolution of T239 (50 km) and L48 for the atmosphere and 1/4° (about 25 km) and 54 levels for the ocean with the coupling interval of 20 minutes (Komori et al., 2008). The medium-resolution version, sometimes called “CFES mini”, has half the horizontal resolution of CFES std. (i.e., T119 and 1/2°) with the coupling interval of 1 hour, and is used for centennial-scale simulations (e.g., Taguchi et al., 2012) and an ensemble-based data assimilation system (CFES–LETKF).

CFES is also used as the base model of a 4D-VAR coupled data assimilation system (Sugiura et al., 2008) with their own model improvements (K7CFES: Mochizuki et al., 2007).