Estimated state of ocean for climate research (ESTOC)

Physical parameters: The assimilated elements in this study are temperature and salinity from ENSEMBLES (EN3) dataset which was quality controlled using a comprehensive set of objective checks developed at the Hadley Centre of the UK Meteorological Office. This dataset is largely composed of observations from the World Ocean Database 2005 and supplemented by data from the GTSPP (Global Temperature and Salinity Profile Program) and Argo autonomous profiling floats.

In addition of EN3 dataset, recent independent MIRAI RV profiles are simultaneously synthesized. Sea-surface dynamic-height anomaly data derived from high-precision multi-satellite altimetry products distributed by Aviso is also incorporated. All observational data were averaged onto 1o by 1o bins and then compiled as series of 10-day means for the surface data and monthly means for the subsurface data.

The control variables are surface fluxes (for net-heat, fresh water, and momentum) and oceanic initial conditions. The assimilation window is 53 years during 1956-2009. Biogeochemical parameters: The synthesis of available observations and a pelagic ecosystem model based on nitrogen cycle produces a dynamically self-consistent dataset.

Optimized 4-dimensional datasets are sought by minimizing a cost function on the basis of Green's function approach. The assimilated elements are the climatological monthly mean nitrate from WOA05, monthly mean ocean color data from SeaWiFS, and annual mean chlorophyll-a from WOA98 as detritus.