Mode Water in the Sea of Japan: A Study on the Reproducibility of Mode Water in the Data-Assimilating Regional Navy Coastal Ocean Model
Mode water in the Sea of Japan (SOJ) is associated with anti-cyclonic eddies that form in the quasi-stationary meanders of the offshore Tsushima Warm Current. Previous work in this region has shown free-running, advanced ocean models are able to capture the physical processes that generate mode water; however, data assimilation is seen to ,I have a negative impact. A 3.5km resolution Regional Navy Coastal Ocean Model is used to assess the ability of a data-assimilating model to reproduce the mode water structure in the SOJ. The model's response to the assimilation of in-situ and synthetic profiles, derived from remotely sensed surface measurements, demonstrates that the model has difficulty recreating and retaining mode water beyond a single forecast run. The model's shortfall occurs because the climatological data, used to derive the synthetic profiles, are too coarse to capture the seasonal mode water evolution of the meander eddies. Two data analysis methods, EOF analysis and multi-variate regression analysis, are utilized to recreate synthetic profiles in the mean locations of the meander eddies during peak mode water occurrence months.
Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
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