Assimilation of Argo Profile Measurements and Sea Surface Temperature Data by the NEMO Ocean Circulation Model Using an Ensemble Kalman Filter and Three-Dimensional Variational Analysis

The results of modeling the thermohaline fields of the World Ocean obtained with the NEMO model using assimilation data from ARGO profiling floats and sea surface temperature (SST) with the two different oceanographic data assimilation systems (ODAS) are presented. One system uses a three-dimensional variational scheme 3D‑Var, and the other ODAS employs the LETKF ensemble Kalman filter. It is shown that both ODAS’s reproduce the three-dimensional temperature and salinity fields approximately equally, but the ODAS based on the ensemble Kalman filter better reproduces SST in the open ocean.