JpGU-AGU Joint Meeting 2017

Presentation information

[EE] Poster

M (Multidisciplinary and Interdisciplinary) » M-GI General Geosciences, Information Geosciences & Simulations

[M-GI28] [EE] Data assimilation: A fundamental approach in geosciences

Mon. May 22, 2017 3:30 PM - 5:00 PM Poster Hall (International Exhibition Hall HALL7)

convener:Shin'ya Nakano(The Institute of Statistical Mathematics), Yosuke Fujii(Meteorological Research Institute, Japan Meteorological Agency), SHINICHI MIYAZAKI(Graduate School of Science, Kyoto University), Takemasa Miyoshi(RIKEN Advanced Institute for Computational Science)

[MGI28-P02] Observation impact on the medium and the long-term range forecast on an eddy-resolving ocean forecast system based on ROMS

*Takashi Setou1, Hiroshi Kuroda5, Daisuke Takahashi5, Tomonori Azumaya5, Takeshi Okunishi2, Daisuke Hasegawa2, Shigeho Kakehi2, Hitoshi Kaneko2, Yugo Shimizu1, Kiyotaka Hidaka1, Yutaka HIroe1, Keiichi Yamazaki1, Takahiko Kameda1, kazuhiro aoki1, Takeshi Taneda3, Kenji Morinaga4, Makoto Okazaki4, Masachika Masujima4, Atsushi Nishimoto1 (1.National Research Institute of Fisheries Science, Japan Fisheries Research and Education Agency, 2.Tohoku National Fisheries Research Institute, Japan Fisheries Research and Education Agency, 3.Seikai National Fisheries Research Institute, Japan Fisheries Research and Education Agency, 4.National Research Institute of Far Seas Fisheries, Japan Fisheries Research and Education Agency, 5.Hokkaido National Fisheries Research Institute, Japan Fisheries Research and Education Agency)

Japan domestic fisheries research institutions constitute a horizontally close-arranged monitoring system around the coastal and the offshore region of Japan in the western North Pacific. Most of these hydrographic data (hereafter FRDATA) have been introduced for an eddy-resolving ocean forecast system, named by the FRA-ROMS (Kuroda et al. 2016, Ishii et al., 2016, Kodama et al. 2015), which developed by Japan Fisheries Research and Education Agency and is based on ROMS (Regional Ocean Modeling System) assimilated with satellite SSH/SST and hydrographic data such as GTSPP and FRDATA. The assimilation scheme, which is founded on the MOVE system developed by the Japan Meteorological Research Institute, is characterized by the following three steps; (1) minimizing the nonlinear cost functions by using a pre-conditioning method, (2) analyzing temperature-salinity profiles by using vertical coupled EOF modes, and (3) assimilating the data analyzed into an ocean model, namely, making reliable reanalysis data by using the Incremental Analysis Updates method. We assessed the relative impact of FRDATA by comparing modeled fields with assimilated and withheld FRDATA. The coastal FRDATA enabled to finely represent hydrographic structures in the coastal region and to remarkably improve the coastal forecast on the medium range forecast (about 1-month). On the other hand, the offshore FRDATA contributed to improve the accuracy not only on the long-term forecast (about 2-months) of some synoptic phenomena (e.g. the Kuroshio) but also of some coastal changes caused by such the phenomena.