Abstract. A quasi-global eddying ocean hindcast simulation using a
new version of our model, called OFES2 (Ocean General Circulation Model for
the Earth Simulator version 2), was conducted to overcome several issues with
unrealistic properties in its previous version, OFES. This paper
describes the model and the simulated oceanic fields in OFES2 compared with
OFES and also observed data. OFES2 includes a sea-ice model and a tidal
mixing scheme, is forced by a newly created surface atmospheric dataset
called JRA55-do, and simulated the oceanic fields from 1958 to 2016. We found
several improvements in OFES2 over OFES: smaller biases in the global sea
surface temperature and sea surface salinity as well as the water mass properties
in the Indonesian and Arabian seas. The time series of the Niño3.4 and
Indian Ocean Dipole (IOD) indexes are somewhat better in OFES2 than in OFES.
Unlike the previous version, OFES2 reproduces more realistic anomalously low
sea surface temperatures during a positive IOD event. One possible cause of
these improvements in El Niño and IOD events is the replacement of the
atmospheric dataset. On the other hand, several issues remained unrealistic,
such as the pathways of the Kuroshio and Gulf Stream and the unrealistic
spreading of salty Mediterranean overflow. Given the worldwide use of the
previous version and the improvements presented here, the output from
OFES2 will be useful in studying various oceanic phenomena with broad
spatiotemporal scales.