A number of activities relevant to the understanding of decadal variability and predictability are being carried out under CLIVAR. Below is a non-exhaustive list of relevant activities that are taking place within the CLIVAR Working Groups and Panels, as well as within US CLIVAR.
CMIP-WGCM-WGSIP oversight group
A subgroup has been formed between the CMIP Panel, the Working Group on Coupled Modelling (WGCM) and the Working Group on Seasonal to Interannual Prediction (WGSIP) to oversee the CMIP5 decadal prediction framework.
The CLIVAR Global Synthesis and Observations Panel (GSOP) is performing an evaluation of ongoing routine global ocean synthesis (often also referred to as ocean reanalysis) products that synthesize all available ocean observations by merging them with global circulation models. These efforts are of particular relevance for decadal predictability and prediction studies by:
Describing the state of the time-varying ocean over the past several decades;
Enabling the study climate dynamics associated with the global ocean over the last several decades;
Facilitating the initialization of coupled models for studies and prediction of seasonal-to-decadal variability.
CLIVAR/GODAE Global Synthesis Evaluation Framework. T. Lee and D. Stammer, May, 2006, Version 3.1.
Atlantic Implementation Panel
Decadal predictability is now a particular focus for CLIVAR's Atlantic Implementation Panel (AIP). The panel has promoted coordinated activities on this topic in the Atlantic, in particular RAPID/MOCHA, AMOC, German CLIVAR-related activities and new EU Framework 7 proposals on decadal predictability and observations in the subpolar gyre. The panel will contribute to EU and US efforts on MOC variability and predictability and is working with WGCM, GSOP and others on the planned WCRP cross cut decadal prediction studies.
Pacific Implementation Panel
The CLIVAR Pacific Implementation Panel have been promoting a Pacific perspective on decadal prediction, emphasizing the effects of its changes on tropical and North Pacific climate and highlighting that decadal prediction is a prediction problem both of the first and second kind (anthropogenic boundary conditions vs. initial condition uncertainties). The Panel has now started an initiative to compute, from the CMIP3 database and the multi-parameter ensemble of the Hadley Center, the multi-model-multi-scenario ensemble mean and variance composites differences for the periods 2011-2020, 2021-2030 and 1980-2010. The analysis will focus on the Pacific and study the forced signal-to-noise ratio for the next 10 and 20 years. For this period the different emission scenarios are still quite similar, so the analysis will take them as members of one ensemble. Primary variables of interest are sea-level, thermocline depth, SST, T2M, P-E, winds. The assumption is that the decadal predictability of Pacific climate originates mostly from the boundary forcing (CO2 and aerosols), rather than from internal climate modes (2nd kind versus 1st kind). Once the analysis is finished a BAMS article will be drafted.
Indian Ocean Panel
The CLIVAR Indian Ocean Panel (IOP) have not overseen any research activities related to the decadal prediction and predictability so far. However, during the last IOP meeting in Pretoria, South Africa, the IOP discussed future directions of its research activities, and all the members agree that the decadal variability and its predictability in the Indian Ocean would be important issue to be addressed in the near future. As the first step toward better understanding of the decadal variability, a possibility of studies on global climate model experiments and surface layer heat budgets using observations and reanalysis products were discussed. Tony Lee (JPL) and Gabe Vecchi (GFDL) were identified as leaders of the discussion on decadal variability and coupled GCM results, respectively.
Variability of the African Climate System Panel
Finally a white paper on decadal prediction and predictability of African climate with links to Indian and Atlantic Oceans is being developed by CLIVAR's Variability of the African Climate System Panel (VACS), with a previous paper published in BAMS (Reason et al., 2006) as a starting point. CLIVAR's Indian Ocean and Atlantic Panels will provide inputs.
Working Group on Decadal Predictability
A short-term (~2 yr) Working Group on Decadal Predictability (DPWG) has been initiated in January 2009 by US CLIVAR. The co-chairs are Amy Solomon, Lisa Goddard, and Arun Kumar. Connections to have been established to relevant International CLIVAR Panels such as WGSIP amd international participants have been entrained into the Working Group.
The DPWG is planning its first meeting for June 19 2009 at NCAR (Boulder).
Terms of reference:
Develop a framework to distinguish natural variability from forced variability for the purpose of assessing the predictability of decadal-scale climate variations that is added by initialization of climate projections.
Work towards understanding predictability of natural decadal variability through metrics that can be used as a strategy to assess and validate decadal-scale climate predictions and simulations.
AMOC Science Team
A US inter-agency group, coordinated through the US CLIVAR Office, has established an AMOC Science Team, chaired by S. Lozier, to execute a 5-yr phased AMOC Implementation Plan. The Science Team is holding its First Annual Meeting in June 2007:
First U.S. Atlantic Meridional Overturning Circulation (AMOC) Annual Meeting - 4-6 May 2009, Annapolis, MD USA
AMOC Implementation Plan: Assessing Meridional Overturning Circulation Variability: Implications for Rapid Climate Change (2007)