Does the CCSM portray El Nino/ENSO events?
Climate models are not like weather forecast models. Years in the Control Run do not go together with calendar years, therefore the control run of the CCSM-3 does not project specific events at the exact time these events occur (like the 1997 El Nino). The CCSM control runs are designed to illustrate internal model variability, by having fixed external forcings. Projections may show warming of the sea surface but in a generic sense. It is more random and is a statistical representation of such events rather than actual. Therefore, a specific event like an El Nino is present in the model only in a statistical sense. Sea surface temperatures for a specific time period will not necessarily be a replication of observed events. CCSM modelers may perform additional runs where they supply ocean observational data, which forces the system to incorporate interactions between ocean and atmosphere and pick out specific events like El Nino.