Mesoscale Reproducibility in Regional Ocean Modelling with a Three-Dimensional Stratification Estimate Based on Aviso-Argo Data |
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| Authors: | Yusuke Uchiyama Ryosuke Kanki Akiko Takano Hidekatsu Yamazaki Yasumasa Miyazawa |
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| Institution: | 1. Department of Civil Engineering, Kobe University, Kobe, Japan;2. Core Research for Evolutionary Science and Technology, Japan Science and Technology Agency, Tokyo, Japan;3. Coastal and Estuarine Environmental Department, Port and Airport Research Institute, Yokosuka, Japanuchiyama@harbor.kobe-u.ac.jp;5. Construction Bureau, City of Kobe, Kobe, Japan;6. Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Tokyo, Japan;7. Application Laboratory, Japan Agency for Marine-Earth Science and Technology, Yokohama, Japan |
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| Abstract: | ABSTRACTFor dynamically consistent, high-resolution, yet cost-effective regional oceanic downscaling modelling, an empirical three-dimensional (3D) density estimate based on publicly available datasets is utilized for the Regional Oceanic Modeling System (ROMS) with simple data assimilation (i.e., TS nudging, where TS stands for temperature and salinity). We rely on a method built upon the two-layer model to reconstruct a mesoscale 3D temperature and salinity field, referred to as Tokyo University of Marine Science and Technology (TUMSAT)-TS, using near real-time altimeter-derived dynamic height along with Argo float profiling data. The TUMSAT-TS is first validated using in situ hydrographic data, then is implemented in the Japan Coastal Ocean Predictability Experiment (JCOPE2)-ROMS downscaling system for the Kuroshio region off Japan. We explore the usability of TUMSAT-TS by carrying out three comparative simulations with temperature and salinity nudging towards the (i) TUMSAT-TS and (ii) JCOPE2-TS fields, and (iii) without the nudging. Whereas the unassimilated case fails to properly account for the Kuroshio, both datasets individually are found to help reproduce the mesoscale variability of the Kuroshio, as well as its transient paths, volume transport, associated kinetic energy (KE) and eddy KE, and seasonally varying stratification. |
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| Keywords: | mesoscale reproducibility Kuroshio Aviso-Argo-derived hydrography ROMS |
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