Estimate of turbulent energy dissipation rate using free-fall and CTD-attached fast-response thermistors in weak ocean turbulence

Autor: Takahiro Tanaka, Shinzou Fujio, Ichiro Yasuda, Yusuke Sasaki, Daisuke Hasegawa, Shuo Zhai, Yasutaka Goto, Daisuke Sasano, Mamoru Tanaka, Sachihiko Itoh, KeungJong Lee, Daigo Yanagimoto
Rok vydání: 2021
Předmět:
Zdroj: Journal of Oceanography. 77:17-28
ISSN: 1573-868X
0916-8370
Popis: The measurement of turbulence is necessary to quantify the vertical, diapycnal transport of heat, water and substances influencing climate, nutrient supply and marine ecosystems. As specialist instrumentation and ship-time are required to conduct microstructure measurements to quantify turbulence intensity, there is a need for more inexpensive and easy measurement methods. This study demonstrated that the turbulent energy dissipation rate, e, estimated from fast-response thermistors Fastip Probe model 07 (FP07) with the depth-average of a > 10 m depth interval well agreed with those from current shear probes to a range of 10–11 W/kg (m2s−3) in the two casts of the most accurate and stable free-fall vertical microstructure profiler, VMP6000 in the Oyashio water. This range cannot be measured with velocity shear probes equipped in smaller profilers in which the lower limit of e > O (10–10) W/kg. These results extend turbulence measurements using the FP07 to 10–11 W/kg. They may be especially useful for turbulence observations in deep oceans where e is generally weak (0.1(W-0.3)$$ criterion (1 s mean lowering rate $$W$$ m/s and its standard deviation $${W}_{\mathrm{sd}}$$ ) under rough conditions where the cast-mean $${W}_{\mathrm{sd}}>$$ 0.07 m/s and the standard deviation of $${W}_{\mathrm{sd}}$$ in each cast $$\sigma$$ >0.05 m/s.
Databáze: OpenAIRE
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