Compare results from 11 global ocean carbon cycle models
to the data-based seasonal climatology or the sea-air CO2 flux
(Takahashi et al., 2003)


List of compared models:

Click here to see the list of all OCMIP models used for comparison, with their code letter appearing on Taylor diagrams.

Only a subset of this list is used in the comparison, due to missing or erroneous model output. MPIM CO2 flux seems to be erroneous because its variability is twice as that of other models, particularly at high latitudes. See Taylor diagrams (links below) to know the actual compared subset.

In this page,we present two set of comparison Taylor diagrams:
  1. OCMIP models only
  2. OCMIP models plus PISCES
    Warning: diagrams that include PISCES are out of date!!!

What is compared:

The data reference for this exercise is the recently revised climatology from Takahashi et al. (2002), which is based on interpolation of 940,000 measurements to a global 4° x 5° grid. For consistency with OCMIP, we calculated the data-based flux by taking the product of Takahashi et al.'s (2002)  fields of DeltapCO2 and the climatological gas transfer coefficient from the standard OCMIP-2 simulations (see http://www.ipsl.jussieu.fr/OCMIP).

We also added for comparison:

  • the Takahashi CO2 flux estimates (2003) which are the revised flux values, computed using 10 meter  wind speeds.
  • the Takahashi CO2 flux estimates (1999) computed using the climatological gas transfer coefficient from the standard OCMIP-2 simulations

We did not use the Takahashi (2002) estimates of the flux because they were computed using the wind speeds at 0.995 sigma (about 40 meters above the sea surface) instead of the wind speeds at 10 meters. The latter are what is required in the formulations by Wanninkhof (1992) and Wanninkhof and McGillis (1999) for the effects of wind speed on the sea-air CO2 gas transfer coefficient.

First, the comparison is made over the global ocean.
Then, it is restricted to North Atlantic, between 22° and 70° North.

1) OCMIP models only

Global:

Taylor diagrams:

North Atlantic:

Taylor diagrams:

2) with PISCES model (warning: out of date!!!)

Global:

Taylor diagrams:

North Atlantic:

Taylor diagrams: