Technical note: Turbulence measurements from a light autonomous underwater vehicle

• Published in: Ocean Science
• Main Authors: E. H. Kolås, T. Mo-Bjørkelund, I. Fer
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2022
• Subjects: Geography. Anthropology. Recreation; G; Environmental sciences; GE1-350; Barents Sea
• Online Access: https://doi.org/10.5194/os-18-389-2022; https://doaj.org/article/e4273395e39545bdbd8bb9c1e0a44270

A self-contained turbulence instrument from Rockland Scientific was installed on a light autonomous underwater vehicle (AUV) from OceanScan Marine Systems and Technology Lda. We report on the data quality and discuss limitations of dissipation estimated from two shear probes during a deployment in the Barents Sea in February 2021. The AUV mission lasted for 5 h, operating at a typical horizontal speed of 1.1 m s −1 . The AUV was programmed to find and cross the maximum along-path thermal gradient at 10 , 20 and 30 m depths along 4 km transects. Although the AUV vibrations contaminate the shear probe records, the noise is mitigated by removing vibration-induced components from shear spectra using the accelerometer signal measured in multiple directions. Dissipation rate estimates in the observed transects varied in the range <math xmlns="http://www.w3.org/1998/Math/MathML" id="M7" display="inline" overflow="scroll" dspmath="mathml"><mrow><mn mathvariant="normal">1</mn><mo>×</mo><msup><mn mathvariant="normal">10</mn><mrow><mo>-</mo><mn mathvariant="normal">8</mn></mrow></msup></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="42pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="29d8f152b26c0b7ba82560a277f85e2a"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="os-18-389-2022-ie00001.svg" width="42pt" height="14pt" src="os-18-389-2022-ie00001.png"/></svg:svg> and <math xmlns="http://www.w3.org/1998/Math/MathML" id="M8" display="inline" overflow="scroll" dspmath="mathml"><mrow><mn mathvariant="normal">6</mn><mo>×</mo><msup><mn mathvariant="normal">10</mn><mrow><mo>-</mo><mn mathvariant="normal">6</mn></mrow></msup></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="42pt" height="14pt" class="svg-formula" ...