Japan Geoscience Union Meeting 2018

Presentation information

[JJ] Oral

A (Atmospheric and Hydrospheric Sciences) » A-OS Ocean Sciences & Ocean Environment

[A-OS17] Ocean circulation and material cycle in coastal seas

Mon. May 21, 2018 3:30 PM - 5:00 PM 106 (1F International Conference Hall, Makuhari Messe)

convener:Akihiko Morimoto(Ehime University), Kiyoshi Tanaka(University of Tokyo), Yuichi Hayami(佐賀大学, 共同), Kazuhiko Ichimi(Faculty of Agriculture, Kagawa University), Chairperson:Ichimi Kazuhiko, Hayami Yuichi

3:30 PM - 3:45 PM

[AOS17-07] Estimation of origin of dissolved organic matter in Osaka Bay and the visualization of its outflow toward the outer Kii Channel

*Shiho Kobayashi1, Satoshi Nakada2, Keigo Yamamoto3, Satosih Akiyama3, Yukio Ueta4, Akihiko Yuasa4, Shigeo Harada5, Toyoho Gosyo5, Masaki Fuchi2, Kengo Ikuta1, Yuuichi Tanaka1, Joji Ishizaka6 (1.Kyoto University, 2.Kobe University, 3.Research Institute of Environment, Argiculture and Fisheries, Osaka Prefecture, 4.Fishries Research Division, Tokushima Prefecture, 5.Fishries Research Division, Wakayama Prefecture, 6.Nagoya University)

Keywords:dissolved organic matter, stable isotope, remote sensing

Studying the behavior of dissolved organic matter (DOM) in coastal seas would assist environmental water management. In this study, field observations to investigate the biogeochemical cycle of dissolved organic carbon and nitrogen (DOC, DON) were conducted in Osaka Bay in February, May, August and November from 2015 to 2017. A remote sensing of the absorption coefficient of colored dissolved organic matter (aCDOM) obtained from geostationary ocean color images (GOCI) as an index for the distributions of DOM was also conducted. The results for a stable isotope of DOC and the relationship between DOC and DON suggested that DOM is generated around the head of Osaka Bay in summer in addition to those supplied from rivers. The results both from field observation and satellite image showed that DOM spreads from Osaka Bay to outer Kii Channel along the coast of Tokushima Prefecture, while the distributions of DOM in inner Kii Channel vary depending on Kuroshio path.