Report of WGCM (Met Office, Exeter, 3-5 Oct 2005) and WGCM/WMP (Met Office, Exeter, 5 Oct 2005 (pm)) meetings Howard Cattle

Key WGCM agenda issues Review of interactions with WCRP developments (JSC, COPES, WMP etc, CLIVAR, CliC, GEWEX) Progress with regional modelling IPCC/CMIP activities and key PCMDI role

The IPCC AR4 motivated the formulation of the largest international global coupled climate model experiment and multi-model analysis effort ever attempted. It is being coordinated by the WGCM Climate Simulation Panel (started in October, 2003) (Panel members: Meehl, Covey, Latif, McAvaney, Mitchell, Stouffer) Fourteen modeling groups from around the world are participating with 21 models; considerable resources have been devoted to this project; PCMDI has archived >27 TeraBytes of model data so far

Results from analyses of the multi-model dataset were presented by 125 scientists at a workshop convened by US CLIVAR and hosted by IPRC (Univ. of Hawaii) March 1-4, 2005, and are feeding directly into the AR4 assessment process

Over 200 papers have been submitted to peer- reviewed journals with results from multi-model analyses for assessment in the IPCC AR4 This is more than triple our most optimistic estimate for participation To date, there are over 400 analysis projects registered at PCMDI; more are being added every week This is the largest, most comprehensive, highest profile and, arguably, most successful project ever organized by WGCM

Key WGCM agenda issues (2) Scenarios for IPCC AR5 and WGCM influence Reports from modelling groups Data management issues (Promote approach used for AR4, including CF conventions for metadata.) The next CMIP activity (20 th century forcing experiments for detection/attribution, anthropogenic vs. natural?, proposed by David Karoly) Other WGCM activities (CFMIP, forcing scenarios, model initialisation (short review of current options), climate change detection, paleo modelling (PMIP)) Links to Earth System Modelling (Carbon cycle, ESSP/Global Carbon Project, C4MIP, biosphere modelling) Interactions with THORPEX

Joint session with WMP (WCRP Modelling Panel) Long discussion on concept of “seamless prediction” (a key element of COPES) Reviews of modelling activities from WGNE; GEWEXModelling Panel; CLIVAR WGCM,WGSIP,WGOMD; CliC, COPES TFSP Monsoon Modelling activities WCRP Observations and Assimilation Panel (WOAP) AMIP

WGCM/WMP meeting - WGOMD Presentation covered P-OMIP and WGOMD -Workshop “Evaluating the ocean component of IPCC-class models”, leading to concept of CORES. Outline of CORES (including mean, interannually varying and freshwater perturbation experiments) Joint WGOMD/CLIVAR Atlantic workshop on Atlantic Thermohaline variability Question for WGOMD - how compatible are the WGOMD freshwater perturbation experiments to the CMIP water hosing experiments? Discussion of model resolutions required for climate experiments