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Minutes of CSM Biogeochemistry Working Group Meeting

by Scott C. Doney

20 August 1998

 

A one-day working group meeting was held at NCAR to outline the goals of the Climate System Model (CSM) Biogeochemistry Working Group over the next one to two years. Scott Doney (co-chair) began the meeting with an introduction and an overview of relevant news from the Breckenridge summer CSM Workshop and steering committee meeting. In brief, the steering committee approved the formation of the CSM Biogeochemistry Working Group and appointed Scott Doney (NCAR) and Inez Fung (University of California, Berkeley) as the co-chairs. The immediate charges of the working group are to:

 - coordinate biogeochemical research in the context of the CSM;

- stimulate the ongoing development of component biogeochemical models; and

- construct a prototype coupled ocean-atmosphere-land biogeochemical calculation focusing on the carbon cycle.

There was general agreement at both the Breckenridge meeting and the August working group meeting that, although the initial focus would be on the global carbon/nitrogen/oxygen cycle, the plan is to include more biogeochemical species (e.g., sulfur, trace gases, trace metals) as our experience and resources grow.

The meeting then continued with a series of short talks on the present state of biogeochemical modeling at NCAR and among the various collaborative groups. Overall, the land and ocean component efforts appear to be in good shape. The weak link at this time appears to be the atmospheric tracer modeling capability for things like CO2, O2, etc., in the Community Climate Model version 3 (CCM3) at NCAR, with the major limitation being simply the need for more people resources (not technical or scientific). The group discussed various ways of addressing this problem including external collaborations.

The question of how to specify land use histories came up as a common scientific theme during the discussions.

The group wrapped up the meeting by identifying a subset of specific tasks for the next one to two years:

Ocean:

- development of a prognostic biotic carbon model, and

- completion of an "AMIP"-style interannual biotic ocean carbon simulation.

Land:

- comparison off-line of a standard set of biological measures (e.g., gross primary production, NDVI, net CO2 flux) for the CASA, LSM, and IBIS models, and

- diagnosis of the seasonal and interannual atmospheric CO2 fields from the land models using an AMIP CCM3 simulation.

Atmosphere:

- run Transcom II SF6 tracer simulations (collaboration with CSU?), and

- add oxygen-18 and deuterium in water tracer capability for hydrological cycle experiments.

Overall:

- compute atmospheric fields from uncoupled ocean and land fluxes of CO2, 13CO2, O2, and 14CO2 for atmospheric inversion calculations, and

- develop coupled ocean-land-atmosphere carbon model and run equilibrium control simulation.