Rob Armstrong, initial convener

At the June 1998 meeting of JGOFS SMP PI's in Boulder, there was general support for the creation of regional testbeds that would allow intercomparison of various biogeochemical models, or the components of such models (e.g., production; export vs mixed layer remineralization; deep-water remineralization; and the mechanistic basis of all these) in a common framework. The rationale and desiderata for such testbeds are described in the report of that meeting. The purpose of the present meeting is to make it happen. As such, the major topics to be discussed are:

• What functions do we need/wish to support?
• How can those functions be supported?

To see how these questions are intertwined, consider the following scenarios:

• The collation of a biogeochemical data set for one region is a relatively simple and non-controversial task that could be done by a single PI working in that region.
• Putting together an accurate and appropriate physical context (mixed-layer?; full 1-D?; 3-D?; all of the above) is much more demanding, and much more controversial, since there will be questions of what constitutes "appropriate". And this judgement is critical, because a biogeochemical model cannot be said to be working we well just because it can compensate for inadequate physics through inappropriate mechanisms. To decide upon an appropriate physical context, one may therefore want some consensus among several groups working in a region: if they can't agree among themselves, why should anyone else use the tool? The need for dedicated personnel also becomes an issue at this level.
• Should we further support the ability to tune the model using inverse techniques? If so, which ones? The experience of the Toulouse workshop shows that this is not a trivial exercise.

So the basic questions that must be addressed (and each must be addressed in the context of the others, so we should let the discussion range freely until we get consensus), are:
 

• WHAT capabilities would we like/need to support?
• WHO among the group of PI's will take charge of seeing that they are supported?
• WHAT resources (personnel and computer access) would be necessary for their support? In particular, is it possible to support these activities in the context of a "largish" ongoing program, or must some PI's take responsibility for writing an SMP proposal to support dedicated personnel?