Japan Geoscience Union Meeting 2019

Presentation information

[E] Oral

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

[A-OS09] Ocean Mixing Processes: Impact on Biogeochemistry, Climate and Ecosystem

Sun. May 26, 2019 1:45 PM - 3:15 PM 303 (3F)

convener:Ichiro Yasuda(Atmosphere and Ocean Research Institute, The University of Tokyo), Toshiyuki Hibiya(Department of Earth and Planetary Science, Graduate School of Science, University of Tokyo), Jun Nishioka(Hokkaido University, Institute of low temperature sciences), Shin-ichi Ito(Atmosphere and Ocean Research Institute, The University of Tokyo), Chairperson:Shin-Ichi Ito(The University of Tokyo)

2:15 PM - 2:30 PM

[AOS09-14] Assessment of the effectiveness of the global ocean state estimation using tide-induced mixing parameterizations

*Satoshi Osafune1, Shuhei Masuda1, Nozomi Sugiura1, Doi Toshimasa1, Tadashi Hemmi1 (1.JAMSTEC)

Keywords:vertical mixing, tide, data assimilation

Recent data synthesis experiments showed that adjusting mixing coefficients through data assimilation approach is a promising way to reduce a global misfit between a model simulation and ocean observations, while mixing coefficients should satisfy constraints from energetics. Aiming for a data synthesis experiment that is energetically consistent with the known constraint on the ocean energy budget and can assimilate turbulence observation data, we have developed a new quasi-global four-dimensional variational dataassimilation system using two parameterizations for tidally induced vertical mixing. As a preliminary preparation of the synthesis experiment, we optimally estimated their parameters along with other physical parameters based on the Green’s function method. The simulation using the optimal parameters well reproduces temperature and salinity in the deep Pacific Ocean. Using this simulation as the first guess field, we are conducting a long-term data synthesis experiment. We will present some preliminary results of the synthesis experiment to assess the effectiveness of our new system.