[A-CG36] Dynamics of Oceanic and Atmospheric Waves, Vortices, and Circulations

[ACG36-P06] Verification for subsurface oceanic structure in OFES2 outputs driven by different wind data sets (J-OFURO3 and JRA55-do)

*Kunio Kutsuwada¹, Hideharu Sasaki², Yoshikazu Sasai² (1.School of Marine Science and Technology, Tokai University, 2.Japan Agency for Marine-Earth Science and Technology)

Keywords:wind-driven circulation, subsurface ocean, OFES2

The OFES is a numerical model that reproduce oceanic circulation and structure with high resolution by input of sea surface flux (momentum, heat and freshwater). In our previous study (Kutsuwada et al. 2018), we have found that there are clear discrepancies in the subsurface oceanic structures of the tropical Pacific between the OFES simulated fields driven by different types of the wind data based on satellite measurement and numerical model reanalysis. These results have suggested that the reproducibility of the simulated field is very sensitive to the selection of surface flux field used as a driving force.
In this study, using the output data of our new version of model (OFES2) simulated by two wind data sets: J-OFURO3 (JO3) and JRA55-do (JR5) during 1991-2017, we attempt to examine their reproducibilities by intercomparisons between the surface and subsurface oceanic fields. The result reveals that there is discrepancy in the sea surface height (SSH) field of the eastern tropical Pacific, which is characterized by the higher SSH by JR5 than that by JO3 throughout our almost study period. Similar differences are found in the subsurface temperature (SUT) fields at about 100m in spite of little difference in the surface temperature ones. Namely, the SUT by JR5 is higher in this area, meaning deeper thermocline depth, than that by JO3. Comparison between the wind stress fields by the two data sets presents that these differences may be due to that in the wind-stress curl fields, which suggests the necessity of the dynamical approach.