IMPLEMENTATION AND EVALUATION OF 4D ENVAR FOR COASTAL BIOGEOCHEMICAL CYCLE ANALYSIS

Abstract

 Material conservation is an important constraint in biogeochemical cycle analysis using numerical models. To assimilate data from a coastal physical-biogeochemical coupled model while ensuring material conservation, we implemented a four-dimensional ensemble variational method (4DEnVar) as a general-purpose method in the Regional Ocean Modelling System (ROMS) and evaluated the usefulness of 4DEnVar. Assimilation of sea surface temperature (SST) from the Japanese geostationary meteorological Himawari8 satellite, and temperature, salinity, chlorophyll-a and dissolved oxygen (DO) observed by monitoring posts, confirmed the improvement of the reproducibility of both physical and biogeochemical fields. In the future, we will study the correction with spatio-temporal distribution.