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Ocean Dynamics

, Volume 66, Issue 1, pp 77–97 | Cite as

Development of an operational coastal model of the Seto Inland Sea, Japan

  • Kei Sakamoto
  • Goro Yamanaka
  • Hiroyuki Tsujino
  • Hideyuki Nakano
  • Shogo Urakawa
  • Norihisa Usui
  • Mikitoshi Hirabara
  • Koji Ogawa
Article
Part of the following topical collections:
  1. Topical Collection on Coastal Ocean Forecasting Science supported by the GODAE OceanView Coastal Oceans and Shelf Seas Task Team (COSS-TT)

Abstract

We have developed a coastal model of the Seto Inland Sea, Japan, for a monitoring and forecasting system operated by the Japan Meteorological Agency (JMA). We executed a hindcast experiment using reanalysis datasets for the atmospheric and lateral boundaries without ocean initialization by data assimilation. The seasonal variability is verified to be realistic by comparing sea surface temperature and salinity of the hindcast experiment with observations. With a horizontal resolution of approximately 2 km, the model represents explicitly various coastal phenomena with a scale of 10–100 km, such as the Kuroshio water intrusion into Japanese coasts. This leads to good representation of intramonthly variations. For example, intensity of the sea level undulations with a period shorter than 23 days shows 1.6-fold improvement, as compared to the present model of JMA with the horizontal resolution of approximately 10 km. In addition to the increased resolution, the model is optimized for coastal modeling as follows. Incorporation of a tidal mixing parameterization reduces a high temperature bias in the Bungo Channel (a western channel of the Seto Inland Sea) and contributes to formation of a frontal structure. An accurate dataset of the river discharges is used for runoff, which has a strong impact on salinity. Enhancement of coastal friction improves surface currents. Owing to the increased resolution and these optimizations, the model shows realistic variability in a wide temporal range from several days to seasons. Root-mean-square errors of sea surface temperature and heights are evaluated as 1–2 K and 7–10 cm, respectively, without data assimilation. In the eastern part, however, the predictability is relatively low, which might be related to representation of an eastward mean flow in the Seto Inland Sea.

Keywords

Coastal modeling Seto Inland Sea Operational model 

Notes

Acknowledgments

We thank the members of the oceanography and geochemistry research department of Meteorological Research Institute for fruitful discussions and helpful comments. This work was funded by MRI and was partly supported by JSPS KAKENHI Grant Number 24740323.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2015

Authors and Affiliations

  • Kei Sakamoto
    • 1
  • Goro Yamanaka
    • 1
  • Hiroyuki Tsujino
    • 1
  • Hideyuki Nakano
    • 1
  • Shogo Urakawa
    • 1
  • Norihisa Usui
    • 1
  • Mikitoshi Hirabara
    • 2
  • Koji Ogawa
    • 3
  1. 1.Meteorological Research InstituteTsukubaJapan
  2. 2.Global Environment and Marine DepartmentJapan Meteorological AgencyTokyoJapan
  3. 3.Fukuoka Regional HeadquartersJapan Meteorological AgencyFukuokaJapan

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