Four-dimensional variational ocean reanalysis for the seas around Japan over 60 years (FORA-JPN60):Part I - system configuration and basic performance

Résumé fourni par la source

Abstract Four-dimensional variational ocean reanalysis for the seas around Japan over 60 years (FORA-JPN60) is unprecedented reanalysis data for the seas around Japan, featuring high-resolution (2 km) and long-term (1960–2020). It is the successor to FORA-WNP30 covering the western North Pacific with 10 km resolution and aims at reproducing coastal circulation variability in addition to mesoscale and larger-scale variability in the open ocean. For this purpose, FORA-JPN60 incorporates various improvements from FORA-WNP30. The horizontal resolution of the ocean model is much increased, and the model incorporates tidal forcing and river discharge. As for data assimilation, an assimilation method for satellite altimeter data is improved to consider non-steric sea-level signals. Furthermore, observational data from fishery agencies and local governments are utilized in the reanalysis experiment to enhance in situ observations around Japan. After evaluating the behavior of the cost function and innovations in the variational assimilation method of FORA-JPN60, sea surface temperature and sea surface height fields are validated with focus on long-term changes, variability and reproducibility in coastal waters. This is part I of a two-part series and a comprehensive evaluation of FORA-JPN60 will be given in part II.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.