title: Assimilation of the seabird and ship drift data in the north-eastern sea of Japan into an operational ocean nowcast/forecast system.
abstract: At the present time, ocean current is being operationally monitored mainly by combined use of numerical ocean nowcast/forecast models and satellite remote sensing data. Improvement in the accuracy of the ocean current nowcast/forecast requires additional measurements with higher spatial and temporal resolution as expected from the current observation network. Here we show feasibility of assimilating high-resolution seabird and ship drift data into an operational ocean forecast system. Data assimilation of geostrophic current contained in the observed drift leads to refinement in the gyre mode events of the Tsugaru warm current in the north-eastern sea of Japan represented by the model. Fitting the observed drift to the model depends on ability of the drift representing geostrophic current compared to that representing directly wind driven components. A preferable horizontal scale of 50 km indicated for the seabird drift data assimilation implies their capability of capturing eddies with smaller horizontal scale than the minimum scale of 100 km resolved by the satellite altimetry. The present study actually demonstrates that transdisciplinary approaches combining bio-/ship- logging and numerical modeling could be effective for enhancement in monitoring the ocean current.
authors.affiliation: Application Laboratory, Japan Agency for Marine-Earth Science and Technology, Showa-machi, Kanazawa-ku, Yokohama, 236-0001, Japan.
authors.forename: Yasumasa
authors.initials: Y
authors.lastname: Miyazawa
authors.affiliation: Application Laboratory, Japan Agency for Marine-Earth Science and Technology, Showa-machi, Kanazawa-ku, Yokohama, 236-0001, Japan.|Center for Marine Environmental Studies, Ehime University, Bunkyo-cho, Matsuyama, Ehime, 790-8577, Japan.
authors.forename: Xinyu
authors.initials: X
authors.lastname: Guo
authors.affiliation: Application Laboratory, Japan Agency for Marine-Earth Science and Technology, Showa-machi, Kanazawa-ku, Yokohama, 236-0001, Japan.
authors.forename: Sergey M
authors.initials: SM
authors.lastname: Varlamov
authors.affiliation: Application Laboratory, Japan Agency for Marine-Earth Science and Technology, Showa-machi, Kanazawa-ku, Yokohama, 236-0001, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Miyama
authors.affiliation: Graduate School of Environmental Studies, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Yoda
authors.affiliation: Atmosphere and Ocean Research Institute, the University of Tokyo, Kashiwa, Chiba, 277-8564, Japan.
authors.forename: Katsufumi
authors.initials: K
authors.lastname: Sato
authors.affiliation: National Maritime Research Institute, Shinkawa, Mitaka, Tokyo, 181-0004, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Kano
authors.affiliation: National Maritime Research Institute, Shinkawa, Mitaka, Tokyo, 181-0004, Japan.
authors.forename: Keiji
authors.initials: K
authors.lastname: Sato
mesh_terms: D025041:Animal Migration; D000818:Animals; D001717:Birds; D004784:Environmental Monitoring; D005544:Forecasting; D007564:Japan; D009792:Oceans and Seas; D012623:Seawater; D012767:Ships; D014872:Water Movements; D014919:Wind