Ocean Renalysis

The 4D-VAR assimilation system used here is the same as in Masuda et al. [2003] covering the global ocean. The OGCM is version 3 of the GFDL Modular Ocean Model (MOM; Pacanowski and Griffies, 1999), which is equipped with several sophisticated parameterization schemes, for example, nonlocal K Profile Parameterization (Large et al., 1994) for mixed layer physics, Gent and McWilliams's scheme (Gent and McWiiliams, 1990) for isopycnal mixing, and quicker advection scheme (Leonald, 1979). The horizontal resolution is 1in both latitude and longitude, with 36 vertical levels spaced from 10m near the sea surface to 400m at the bottom. This model has good capability to reproduce ocean circulation processes and is expected to form a platform suitable for the use of the 4D-VAR adjoint model. The assimilated elements in this study are the temperature and salinity from the World Ocean Database 1998 (for climatologies) and the FNMOC, OI SST values, and sea-surface dynamic-height anomaly data compiled by AVISO. All observational data were averaged onto 1 degree by 1 degree bins and then compiled as series of 10-day means for the surface data and monthly means for the subsurface data.