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physics paper outline



Dear all,

Enclosed below is a draft outline for an OCMIP paper on the basic physical 
framework of the models. This paper would supplment and complement
the work already being lead by Jean-Claude on the CFC simulations.
The outline is based on what was presented at the OCMIP meeting in Gif 
plus my own personal opinions (i.e. please don't think anything is set 
in stone). I circulated this draft earlier during the summer to a subset 
of the group and got generally positive feedback. We would need some
additional physical diagnostics from each of the groups (no additional
runs or at most one year with added diagnostics). If possible, I would 
like to suggest a Dec. 1st deadline for submission of the new results.
NCAR will "volunteer" to lead the analysis (unless someone else is
dying to do it.) Thank you in advance for your comments/suggestions/advice 
and most importantly labor.

I have tried to focus on how to move beyond simply a "beauty
contest" (though clearly that will play part) toward the underlying
science issues. I did not choose to outline "fast track" papers
(e.g. brief note to GRL with 2 or 3 figures), but we could certainly
condense out one or two "dramatic" results for such papers if the
group so desires.

Unless otherwise stated all figures (marked as *) will include all
of the OCMIP models (either color line diagrams or multi-panel
contour plots) and observations where applicable. I have included
more figures than will likely be incorporated in the final papers to
facilitate our analysis, but clearly this is only a small subset of
all of the possible figures. Figures or analysis that will require
additional information are marked by a #. Data sets other than those
already being collected are marked as [reference]. The references are a
suggested subset off the top of my head only; please do not take
offense at any omissions. The author list includes the people who
expressed interest in the project but all are of cource welcome.

Scott

*******
Outline of OCMIP-2 Physics Paper

(Physics subgroup Doney, Dutay, Bullister, Follows, Marshall, Lindsay,
Gruber, Najjar, and Orr [in no particular order] + rest of OCMIP)

The overall objectives of the paper are three fold:
   -assessing the skill of the OCMIP simulations relative to
    large-scale, integrative measures of ocean general circulation
   -determining the model physical aspects (surface forcing; isopycnal
    and diapycnal mixing; model grid architecture; topography; sea-ice
    treatment) leading to significant model-model and model-data
    differences

Introduction
   -OCMIP1 and OCMIP2 project background (Orr et al report)
   -Relevant outstanding questions from OCMIP1 (e.g. southern
      ocean ventilation) (Sarmiento et al.; Orr et al.)
   -Pose set of hypotheses based expected results from literature
    (e.g. Gent-McWilliams scheme effect on southern ocean dynamics;
    diapycnal diffusivity on heat transport and thermocline thickness
    F. Bryan; z-models relative to sigma models poor performance on
    overflows; sea-ice impact on deep salinity Duffy and Calderia)
Methods and Models
   -More thorough description of models in OCMIP including the Table
    shown at Gif
    Try to lump models into similar classes (e.g. z-models with
    Gent-McWilliams isopycnal mixing)
Results
   -Surface forcing and mixing
       *net annual surface heat and freshwater flux maps # (e.g.
        freshwater fluxes important for DIC and alkalinity)
       *zonal average heat and freshwater transport (at steady state,
        integral of surface fluxes) # [MacDonald and Wunsch; Wiffels]
       *global (basin?) water mass transformation rates
           (ala Speer and Tziperman; Doney et al., 1998) #
       *mixed layer depth (austral and boreal winter) #
   -Water column hydrography
       *global (basin) annual mean depth profiles of T and S [Levitus] #
       *basin (Atlantic, Pac., Indian) zonal average T, S, density
        contour plots [Levitus] #
       *compare thermocline depth and thickness, deep T and S
        properties; large-scale water mass patterns [Levitus]
   -Wind-driven circulation
       *annual mean barotropic streamfunction (if very different also
        look at annual mean wind stress) #
        strength of gyres related to subduction rate; ACC tied to
        isopycnal scheme, AABW formation, sea-ice etc.
       *possible compute measure of thermocline subduction ala
        Marshall's work #
   -Thermohaline circulation
       *annual mean Atlantic meridional overturning circulation #
       *annual mean Pacific meridional overturning circulation #
       *bottom topography (below say 2000 m)
       *bottom velocity vectors (below say 2000 m) #
       *transport by temperature layers and basins ala [MacDonald and
        Wunsch] (see also Gent et al., 1998).
        strength and depth of NADW and AABW formation, balance of
        northern and southern deep water formation; deep water flow
        patterns; where deepwater upwelling/transformations occur
Summary and Discussion
References

List of new required monthly diagnostics from steady-state solution of 
each model:

- -3-D temperature and salinity
- -3-D u and v velocity (w by divergence)
- -2-D surface heat and freshwater fluxes
- -mixed layer depth
- -2-D barotropic streamfunction
- -meridional overtunring ciruclation by basin


Information on diffusivity fields



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Scott Doney                                   phone: (303) 497-1639
Climate and Global Dynamics                   FAX: (303) 497-1700
National Center for Atmospheric Research      email: doney@ncar.ucar.edu
P.O. Box 3000                                 
Boulder, CO 80307                             world wide web:
USA                          http://www.cgd.ucar.edu:80/oce/doney/doney.html

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