JpGU-AGU Joint Meeting 2020

Presentation information

[E] Oral

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

[A-OS24] Exploring new frontiers of oceanic mixing research in the next decade

convener:Toshiyuki Hibiya(Department of Earth and Planetary Science, Graduate School of Science, University of Tokyo), Ichiro Yasuda(Atmosphere and Ocean Research Institute, The University of Tokyo), Lakshmi Kantha(Aerospace Engineering Sciences, University of Colorado, Boulder, Colorado, USA)

[AOS24-03] Development of efficient and autonomous microstructure measurement system using fast-response thermistors attached to CTD, glider and deep-profiling float, to elucidate vertical distribution

*Ichiro Yasuda1, Keunjong Lee1, Maki Nagasawa1, Shuo Zhai1, Yusuke Sasaki1, Daigo Yanagimoto1, Shinzo Fujio1, Mamoru Tanaka1, Yasutaka Goto2, Toshiya Nakano2, Daisuke Sasano2, Takahiro Tanaka4, Shinya Kouketsu3 (1.Atmosphere and Ocean Research Institute, The University of Tokyo, 2.Japan Meteorological Agency Japan, 3.Japan Agency of Marine-Earth Science and Technology, 4.Tohoku National Fisheries Research Institute, Fisheries Research and Education Agency)

Keywords:Turbulence, observation

A new efficient microstructure measurement with fast-response thermistors attached to CTD, underwater glider and deep float has been elaborated. The CTD-attached thermistor measurements were confirmed to be valid in the weak turbulent energy dissipation down to 10-11W/kg by comparing with the one by free-fall instrument with the best accuracy, and revealed cross-Pacific top-bottom turbulence distribution. Vertical distribution of turbulent energy dissipationis found to be proportional withlocal squared buoyancy frequency N2(representing density vertical gradient) and local internal tide energy generation and dissipation, indicating that energy dissipation of tide-induced turbulence occurs in the main thermocline. Thermistor measurements attached to gliders and deep floats were also confirmed to be useful to measure weak turbulence area as in the deep water as well as the water where double-diffusive convections work. These contribute to revising models of tide-induced three-dimensional distribution used in ocean/climate models, which will contribute to reproducing ocean meridional overturning circulation and oceanic heat/material circulation.