History

The algorithms explored in SODA are sequential estimation with empirically modeled error covariances. The basic algorithm is described in two papers (Carton et al., 2000a,b: see http://www.meto.umd.edu/~carton/carton/ref.html)[1]. We have recently implemented an improved two-stage bias correction algorithm (Chepurin et al., 2004; submitted, see http://www.atmos.umd.edu/~carton/bias). The latest release of the MOM2-based moderate resolution version is beta23, for which a brief description is provided below.

We are now exploring an eddy-permitting reanalysis based on the Parallel Ocean Program POP-1.4 model with 40 levels in the vertical and a 0.4x0.25 degree displaced pole grid (25 km resolution in the western North Atlantic). The first version of this we will release is SODA1.2, a reanalysis driven by ERA-40 winds covering the period 1958-2001 (extended to the current year using available altimetry).

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[1] (see also: Chepurin and Carton, 1999). (NOTE: These papers are based on our older version of lower resolution run which is global with 2.0x2.5 lat-lon horizontal resolution in midlatitude reducing to 0.5x2.5 resolution in the tropics for a total 96x146 horizontal grid points. The vertical resolution is the same 20 levels.)