Improvement of the SIGMA-1 measuring complex for studies of Langmuir circulations and surface wave breaking in the Black Sea

M. I. Pavlov*, A. M. Chukharev

Marine Hydrophysical Institute of RAS, Sevastopol, Russia

* e-mail: mixail.pavlov.1993@mail.ru

Abstract

The purpose of this article is to describe modernization of SIGMA-1 measuring complex. The modernization was performed to improve the quality of research of the wave breaking mechanisms and Langmuir circulations at the stationary oceanographic platform MHI. The article deals with the effects of natural oscillations of the device and changes in the housing position on the measured components of the flow velocity vector. The device natural oscillations are recorded by a position monitoring system consisting of a set of sensors: accelerometers and a magnetometer. A model study of permissible rotations and maximum tilt angles showed that in the absence of an angular velocity sensor, the uncorrected measured components of the flow velocity vector can differ significantly from the actual ones. To solve this problem, MPU-9250 module with an accelerometer, gyroscope and magnetometer was chosen; Arduino Nano was used as a microcontroller system. Based on the theory of calculating spatial angles, a program for correcting the measured components of velocity pulsations for the new module was developed in Arduino IDE programming environment. The optimal program (Magnetto) for calibrating the magnetometer was selected as the most accurate and satisfying the conditions of use at the oceanographic platform. The main stages of sensor calibration are described. The flow velocity components measured in the device coordinate system are adjusted for the values of tilt angles, angular and linear velocities, the calculation is performed using the eddy correlation method. The developed system has been tested on specialized equipment in laboratory setting and has the following characteristics: within the range –30…+30° the maximum pitch error is 0.31°; the maximum roll error is 0.42°; the maximum magneto-meter error is 2.09°. The achieved characteristics allow significant increase in the accuracy of measuring the velocity vector and reliability estimate of influence of various physical processes on the vertical exchange.

Keywords

Langmuir circulations, wave breaking, contact research methods, navigation system, MEMS calibration, eddy correlation method, MPU-9250, AK8963C.

Acknowledgments

The work was performed within the framework of the state task on the theme No. 0827-2018-0003.

For citation

Pavlov, M.I. and Chukharev, A.M., 2021. Improvement of the SIGMA-1 Measuring Complex for Studies of Langmuir Circulations and Surface Wave Breaking in the Black Sea. Ecological Safety of Coastal and Shelf Zones of Sea, (1), pp. 129–148. doi:10.22449/2413-5577-2021-1-129-148 (in Russian).

DOI

10.22449/2413-5577-2021-1-129-148

References

  1. Monin, A.S. and Ozmidov, R.V., 1985. Turbulence in the Ocean. Dordrecht, Holland: D. Reidel Publishing Company, 246 p.
  2. Donelan, M.A., Madsen, N., Kahma, K.K. and Tsanis, I.K., 1999. Apparatus for Atmospheric Surface Layer Measurements over Waves. Journal of Atmospheric and Oceanic Technology, 16(9), pp. 1172-1182. https://doi.org/10.1175/1520-0426(1999)0161172:AFASLM2.0.CO;2
  3. Drennan, W.M., Donelan, M.A., Terray, E.A. and Katsaros, K.B., 1996. Oceanic Turbulence Dissipation Measurements in SWADE. Journal of Physical Oceanography, 26(5), pp. 808-815. https://doi.org/10.1175/1520-0485(1996)0260808:OTDMIS2.0.CO;2
  4. Donelan, M.A., Drennan, W.M. and Katsaros, K.B., 1997. The Air–Sea Momentum Flux in Conditions of Wind Sea and Swell. Journal of Physical Oceanography, 27(10), pp. 2087-2099. https://doi.org/10.1175/1520-0485(1997)0272087:TASMFI2.0.CO;2
  5. Gemmrich, J.R. and Farmer, D.M., 1999. Near-Surface Turbulence and Thermal Structure in a Wind-Driven Sea. Journal of Physical Oceanography, 29(3), pp. 480–499. https://doi.org/10.1175/1520-0485(1999)0290480:NSTATS2.0.CO;2
  6. Gemmrich, J.R. and Farmer, D.M., 1999. Observations of the Scale and Occurrence of Breaking Surface Waves. Journal of Physical Oceanography, 29(10), pp. 2595–2606. https://doi.org/10.1175/1520-0485(1999)0292595:OOTSAO2.0.CO;2
  7. Gemmrich, J.R. and Farmer, D.M., 2004. Near-Surface Turbulence in the Presence of Breaking Waves. Journal of Physical Oceanography, 34(5), pp. 1067–1086. https://doi.org/10.1175/1520-0485(2004)0341067:NTITPO2.0.CO;2
  8. Weller, R.A., Dean, J.P., Price, J.F., Francis, E.A., Marra, J. and Broadman, D.C., 1985. Three-Dimensional Flow in the Upper Ocean. Science, 227(4694), pp. 1552–1556. doi:10.1126/science.227.4694.1552
  9. Weller, R.A. and Price, J.F., 1988. Langmuir Circulation within the Oceanic Mixed Layer. Deep Sea Research Part A. Oceanographic Research Papers, 35(5), pp. 711747. https://doi.org/10.1016/0198-0149(88)90027-1
  10. Zedel, L. and Farmer, D., 1991. Organised Structures in Subsurface Bubble Clouds: Langmuir Circulation in the Open Ocean. Journal of Geophysical Research: Oceans, 96(С5), pp. 8889–8900. doi:10.1029/91JC00189
  11. Thorpe, S.A., 2004. Langmuir Circulation. Annual Review of Fluid Mechanics, 36, pp. 55–79. doi:10.1146/annurev.fluid.36.052203.071431
  12. Thorpe, S.A., Osborn, T.R., Jackson, J.F.E., Hall, A.J. and Lueck, R.G., 2003. Measurements of Turbulence in the Upper-Ocean Mixing Layer Using Autosub. Journal of Physical Oceanography, 33(1), pp. 122145. https://doi.org/10.1175/1520-0485(2003)0330122:MOTITU2.0.CO;2
  13. Anctil, F., Donelan, M.A., Drennan, W.M. and Graber, H.C., 1994. Eddy-Correlation Measurements of Air-Sea Fluxes from a Discus Buoy. Journal of Atmospheric and Oceanic Technology, 11(4), pp. 1144–1150. https://doi.org/10.1175/1520-0426(1994)0111144:ECMOAS2.0.CO;2
  14. Samodurov, A.S., Dykman, V.Z., Barabash, V.A., Efremov, O.I., Zubov, A.G., Pavlenko, O.I. and Chukharev, A.M., 2005. “Sigma-1” Measuring Complex for the Investigation of Small-Scale Characteristics of Hydrophysical Fields in the Upper Layer of the Sea. Physical Oceanography, 15(5), pp. 311–322. https://doi.org/10.1007/s11110-006-0005-1
  15. Dykman, V.Z. and Efremov, O.I., 2000. [Electromagnetic Sensor for Measurement of the Current Velocity Vector Fluctuations]. In: MHI, 2000. Ekologicheskaya Bezopasnost' Pribrezhnykh i Shel'fovykh Zon i Kompleksnoe Ispol'zovanie Resursov Shel'fa [Ecological Safety of Coastal and Shelf Zones and Comprehensive Use of Shelf Resources]. Sevastopol: ECOSI-Gidrofizika, pp. 318–324 (in Russian).
  16. Chukharev, A.M., 2010. Field Measurements of Turbulent Kinetic Energy Dissipation in Sea Surface Layer. In: MHI, 2010. Ekologicheskaya Bezopasnost' Pribrezhnykh i Shel'fovykh Zon i Kompleksnoe Ispol'zovanie Resursov Shel'fa [Ecological Safety of Coastal and Shelf Zones and Comprehensive Use of Shelf Resources]. Sevastopol: ECOSI-Gidrofizika. Iss. 21, pp. 231–238 (in Russian).
  17. Farhang-Boroujeny, B., 1999. Adaptive Filters: Theory and Applications. New York: John Wiley & Sons, 548 p.

Download the article (PDF, in Russian)