Summary

The objectives of the Canadian Global Coupled Climate Carbon Model Network (CGC3M) are:
  1. To develop and test an integrated carbon (C) cycle model including terrestrial, oceanic and atmospheric components for inclusion in the Canadian Centre for Climate Modelling and Analysis (CCCma) Coupled General Circulation Model (CGCM);
  2. to incorporate and test the coupled C-cycle model in CGCM simulations aimed at making transient climate change calculations with C as a prognostic (forecasted) variable; and
  3. to perform studies of the role of carbon dioxide (CO2) and methane (CH4), the two most important radiatively active greenhouse gases (GHGs) in regulating the climate system, in order to investigate how the C-cycle may respond to a changing climate through dynamic feedbacks.

To attain these objectives the network is divided into three theme areas: terrestrial, ocean, and atmospheric modelling. The atmospheric theme is the most advanced with CCCma having produced three Atmospheric General Circulation Models (AGCMs) in previous work and currently working on a fourth. However, the AGCM has to be modified to accept mass inputs of CO2, CH4 and possibly N2O and transport them to obtain concentration fields. Since CH4 and N2O are reactive gases the model also requires some parameterization for relevant aspects of atmospheric chemistry. A physical ocean model is part of the CGCM and the objective of this network is to incorporate inorganic and organic carbon cycling. The terrestrial theme is the least developed. The Canadian Land Surface scheme (CLASS) has been developed and version 2.7 is now implemented in the most recent versions of the AGCM (and hence the CGCM). This is a biophysical model and contains no carbon cycling. The objective of the terrestrial theme is to develop a dynamic global vegetation model (DGVM) that would eventual be incorporated into the CGCM.

The CGC3M network received notification of support from the Canadian Foundation for Climate and Atmospheric Sciences (CFCAS) in September 2001 and received the actual funds in late October, 2001. A second source of direct funding for the CGC3M network is the Climate Research Network, administered by the Canadian Institute for Climate Studies (CICS). These funds were received in late August 2001. Once funding was received the research began immediately. We have held two CGC3M Science Workshops. The first was held in January 2002 in Victoria. This was a full science team workshop to organize the specific tasks of the project and to ensure good communications between the scientists involved in each theme. The second science workshop was held in June 2002 in Toronto. This workshop focussed on the terrestrial modelling with representation from the other two theme areas. A third science workshop is being organized for late September 2002 for the ocean and atmospheric themes. This will be held in Victoria and the second full science team workshop will be held early in 2003.

Communications

Communication within the CGC3M science team is very active and successful. With a project of such a diverse nature there is a huge amount of education involved and this has begun in earnest. It is not unfair to say that at the beginning of this network the atmospheric scientists were relatively ignorant of how the terrestrial carbon cycle operated, and the terrestrial scientists had little comprehension of global scale atmospheric processes and global scale modelling. We will continue to have our regular science meetings.

We are beginning to develop the CGC3M web site. We have hired one of our incoming M.Sc. students to work part time on the web page. The web site will have a public component for general information and network components to be used for internal exchange of information.

The network has been in existence for only six months, and so publications arising from this work are not really to be expected. Nevertheless, one paper has been submitted describing the operational model version (in column mode) and its evaluation (V. Arora, CCCma).

Additional Networking

As various other projects allied with the coupled climate carbon model initiative continue or are beginning we are finding many more opportunities for useful collaboration than was originally anticipated. For example, the work by the McGill group in Panama on CO2 exchange from plantations and pastures is becoming an element in the evaluation of C-CLASS. This research is also aiding in the development and testing of various soil respiration routines. In Canada there is a deficiency in high-quality data sets for ecosystems outside Canada, but global model evaluation has to incorporate all major biomes. Connections to projects involving carbon-cycle research in regions representative of diverse eco-climatic regimes are therefore vital to the current project. A second example is the initiation of Fluxnet Canada. The CGC3M terrestrial theme has identified soil respiration and carbon allocation as key elements for improvement in the terrestrial module. Fluxnet Canada in response to this is putting a significant and additional effort into attempting to partition the components of soil respiration. This process is aided greatly by several members of this modelling network also being co-investigators on Fluxnet Canada.

We are also pursuing a link between the CGC3M network and BIOCAP Canada. BIOCAP Canada is facilitating research in four areas of Canada's carbon cycle. The area related to natural ecosystems and carbon cycling is the one most allied with our efforts. There are two important aspects that can be developed with this link. First BIOCAP Canada is a potential source of additional funding for the network if the need arises. Secondly, and more importantly, BIOCAP Canada has a very significant policy component in its mandate. It has representation from the three major federal departments involved in greenhouse gas management, several provincial governments, private sector corporations, non-governmental organizations, and public interest groups. It therefore represents a significant cross section of stakeholders in Canada's greenhouse gas management. While the focus of CGC3M network is the development of a coupled climate carbon model for climate simulation, we as a group also have to be aware that the model or some derivatives of it would be useful in addressing questions of the permanence of carbon stores and the potential change in natural exchanges due to unforeseen climate carbon feedbacks.

We are interacting with Andrew Weaver's CFCAS project to implement the carbon cycle in his paleoclimate earth system model of intermediate complexity (EMIC). His research associate Katrin Meissner, attended our recent workshop in Toronto and presented initial results with the UK Hadley Centre terrestrial carbon model coupled to their EMIC. It provided our terrestrial group with some exposure to these issues involved in developing a model for use at the global scale.

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