YASUDA, Ichiro

Atmosphere and Ocean Research Institute

Office: Atmosphere and Ocean Research Institute -B-610
TEL: +81-4-7136-6040
FAX: +81-4-7136-6056

Research Field

Physical Oceanography・Ocean ecosystem dynamics・ Fisheries Oceanography

Current Research

My research interest is to understand the meso-scale and large-scale ocean circulation,their influence on the long-term climate variability and influence on the ocean ecosystem, using observations, data analyses, and numerical modeling. One of the recent focuses is on the North Pacific Intermediate Water which is a main salinity minimum in the North Pacific and subtropical-subarctic gyre interactions. My group made large-scale and intensive hydrographic and microstructure observations in the Kuroshio, Oyashio and Okhotsk Sea, and revealed the origin and transport route of the water-mass. This effort is continuing to quantify the cross-gyre transport and to clarify the mixing and dynamical processes in the Kuroshio-Oyashio confluence and Okhotsk Sea water-mass formation and outflow. This will lead to carbon-cycle studies with chemical oceanographers to estimate what amount of materials such as CO2 go to subsurface. My other present focus is on the inter-decadal ocean/climate variations and its influence on the ocean-ecosystem, especially on the Japanese sardine. My group recently revealed relationship between the sea-surface temperature in the Kuroshio Extension and the recruitment of the Japanese sardine. We are now trying to find more direct cause and/or why the SST changes with the period of more than 50 years. My other interest is dynamics of oceanic meso-scale eddies and their influence on the large-scale ocean circulation to improve skills of ocean modeling and prediction.

Representative Publications

1. Yasuda, I. (2018): Impact of the astronomical lunar 18.6-yr tidal cycle on El-Niño and Southern Oscillation. Scientific Reports, DOI: 10.1038/s41598-018-33526-4
2. Y. Goto, I. Yasuda and M. Nagasawa (2018): Comparison of turbulence intensity from CTD-attached and free-fall microstructure profilers. Journal of Atmosphere and Ocean Technology, 35, 147-162, DOI: 10.1175/JTECH-D-17-0069.1
3. I. Yasuda, The origin of the North Pacific intermediate water, J. Geophys. Res., 102(C1), 893-909, 1997.