Investigation of the Upper Mixed Layer Variability in the Barents and Kara Seas

A. A. Bukatov, E. A. Pavlenko✉, N. M. Solovei

Marine Hydrophysical Institute of RAS, Sevastopol, Russian Federation

✉ e-mail: ekk.pavlenko@yandex.ru

Abstract

Purpose. The study is purposed at analyzing spatial and temporal climatic variability of the upper mixed layer in the Barents and Kara seas on a climatic scale.

Methods and Results. Potential water density is calculated based on the ORAS5 reanalysis data on the average monthly values of potential temperature and salinity at the nodes of a grid of about 10 km with an irregular step over vertical up to a depth of about 400 m for the 1958–2022 period. The formed density array makes it possible to determine the upper mixed layer thickness in the Barents and Kara seas. Threshold criterion ∆σ = 0.03 kg/m3 is used for its estimation. The obtained results permit to identify the areas notable for significant variability of the upper mixed layer thickness.

Conclusions. The analysis shows that the upper mixed layer maximum development falls on February and March, whereas the minimum one – on June and July. Thus, the highest values of the upper mixed layer thickness are observed in the seas under consideration during increased autumn-winter convection. In the cold half of a year (November – April), the upper mixed layer thickness averages 105 m in the Barents Sea and 23 m in the Kara Sea. The analysis of interannual variability of the average annual thickness values of these layers shows the presence of a positive climatic trend, i. e. a thickness increase in the upper mixed layers in the Barents and Kara seas in 1958–2022. The upward trend is observed both in the cold and warm halves of a year. The values of average annual thickness trends of the upper mixed layers in the Barents and Kara seas average 1.3 m/10 years and 1.2 m/10 years, respectively.

Keywords

Barents Sea, Kara Sea, upper mixed layer thickness, vertical mixing, linear trend, interannual variability

Acknowledgements

The study was carried out within the framework of theme of state assignment of FSBSI FRS MHI FNNN-2024-0001.

Original russian text

Original Russian Text © A. A. Bukatov, E. A. Pavlenko, N. M. Solovei, 2025, published in MORSKOY GIDROFIZICHESKIY ZHURNAL, Vol. 41, Iss. 2, pp. 160–170 (2025)

For citation

Bukatov, A.A., Pavlenko, E.A. and Solovei, N.M., 2025. Investigation of the Upper Mixed Layer Variability in the Barents and Kara Seas. Physical Oceanography, 32(2), pp. 187-196.

References

  1. Luchin, V.A., 2018. Intra-Annual Variability of the Mixed Layer Parameters in the Okhotsk Sea. Izvestiya TINRO, 195(4), pp. 170-183. https://doi.org/10.26428/1606-9919-2018-195-170-183
  2. Aagaard, K. and Coachman, L.K., 1975. Toward an Ice-Free Arctic Ocean. Eos, Transactions American Geophysical Union, 56(7), pp. 484-486. https://doi.org/10.1029/EO056i007p00484
  3. Rudels, B., Anderson, L.G. and Jones, E.P., 1996. Formation and Evolution of the Surface Mixed Layer and Halocline of the Arctic Ocean. Journal of Geophysical Research: Oceans, 101(C4), pp. 8807-8821. https://doi.org/10.1029/96JC00143
  4. Zakharov, V.F., 1996. Sea Ice in the Climate System. Saint Petersburg: Gidrometeoizdat, 213 p. (in Russian).
  5. Cherniavskaia, E.A., Timokhov, L.A., Karpiy, V.Y. and Malinovskiy, S.Y., 2020. Interannual Variability of Parameters of the Arctic Ocean Surface Layer and Halocline. Arctic and Antarctic Research, 66(4), pp. 404-426. https://doi.org/10.30758/0555-2648-2020-66-4-404-426
  6. Frolov, I.E., Gudkovich, Z.M., Karklin, V.P., Kovalev, E.G. and Smolyanitsky, V.M., 2007. Scientific Research in the Arctic. Vol. 2. Climatic Changes in the Ice Cover of the Eurasian Shelf Seas. Saint Petersburg: Nauka, 135 p. (in Russian).
  7. Stroeve, J., Holland, M.M., Meier, W., Scambos, T. and Serreze, M., 2007. Arctic Sea Ice Decline: Faster than Forecast. Geophysical Research Letters, 34(9), L09501. https://doi.org/10.1029/2007GL029703
  8. Kwok, R. and Rothrock, D.A., 2009. Decline in Arctic Sea Ice Thickness from Submarine and ICESat Records: 1958–2008. Geophysical Research Letters, 36(15), L15501. https://doi.org/10.1029/2009gl039035
  9. Rostov, I.D., Dmitrieva, E.V., Rudykh, N.I. and Vorontsov, A.A., 2019. Climatic Changes of Thermal Condition in the Kara Sea at Last 40 Years. Arctic and Antarctic Research, 65(2), pp. 125-147. https://doi.org/10.30758/0555-2648-2019-65-2-125-147 (in Russian).
  10. Ashik, I.M., ed., 2021. The Seas of the Russian Arctic in Modern Climatic Conditions. Saint Petersburg: AARI, 360 p. (in Russian).
  11. Macdonald, R.W., Harner, T. and Fyfe, J., 2005. Recent Climate Change in the Arctic and Its Impact on Contaminant Pathways and Interpretation of Temporal Trend Data. Science of the Total Environment, 342(1-3), pp. 5-86. https://doi.org/10.1016/j.scitotenv.2004.12.059
  12. Frolov, I.E., Ashik, I.M., Kassens, H., Polyakov, I.V., Proshutinsky, A.Yu., Sokolov, V.T. and Timokhov, L.A., 2009. Anomalous Variations in the Thermohaline Structure of the Arctic Ocean. Doklady Earth Sciences, 429(2), pp. 1567-1569. https://doi.org/10.1134/S1028334X09090323
  13. Peralta-Ferriz, С. and Woodgate, R.A., 2015. Seasonal and Interannual Variability of Pan-Arctic Surface Mixed Layer Properties from 1979 to 2012 from Hydrographic Data, and the Dominance of Stratification for Multiyear Mixed Layer Depth Shoaling. Progress in Oceanography, 134, pp. 19-53. https://doi.org/10.1016/j.pocean.2014.12.005
  14. Vlasenkov, R.E., Smirnov, A.V. and Makshtas, A.P., 2010. Estimation of Potential Heating of the Surface Layer of the Kara and Laptev Seas in 2007 and 2008. Arctic and Antarctic Research, (2), pp. 35-39 (in Russian).
  15. Sirevaag, A., De La Rosa, S., Fer, I., Nicolaus, M., Tjernström, M. and McPhee, M.G., 2011. Mixing, Heat Fluxes and Heat Content Evolution of the Arctic Ocean Mixed Layer. Ocean Science, 7(3), pp. 335-349. https://doi.org/10.5194/os-7-335-2011
  16. Bukatov, A.A., Pavlenko, E.A. and Solovei, N.M., 2023. River Runoff Influence on the Density Stratification of the Russian Arctic Seas. In: T. Chaplina, ed., 2023. Processes in GeoMedia – Volume VI. Springer Geology Series. Cham: Springer, pp. 523-536. https://doi.org/10.1007/978-3-031-16575-7_47
  17. Smirnov, A.V. and Korablev, A.A., 2010. Interrelationship between Mixed Layer Characteristics and Atmospheric Heat Fluxes in the Nordic Seas. Arctic and Antarctic Research, (3), pp. 79-88 (in Russian).
  18. Toole, J.M., Timmermans, M.L., Perovich, D.K., Krishfield, R.A., Proshutinsky, A. and Richter-Menge, J.A., 2010. Influences of the Ocean Surface Mixed Layer and Thermohaline Stratification on Arctic Sea Ice in the Central Canada Basin. Journal of Geophysical Research: Oceans, 115(C10), C10018. https://doi.org/10.1029/2009JC005660
  19. Jackson, J.M., Williams, W.J. and Carmack, E.C., 2012. Winter Sea-Ice Melt in the Canada Basin, Arctic Ocean. Geophysical Research Letters, 39(3), L03603. https://doi.org/10.1029/2011gl050219
  20. Lisitsyn, A.P., ed., 2021. The Barents Sea System. Moscow: GEOS, 672 p. https://doi.org/10.29006/978-5-6045110-0-8/(4) (in Russian).
  21. Bukatov, A.A., Pavlenko, E.A. and Solovei, N.M., 2018. Features of Spatial-Time Variability of Väisälä-Brunt Frequency in Barents and Kara Seas. Processes in GeoMedia, 3(16), pp. 1004-1013 (in Russian).
  22. Bukatov, A.A., Solovei, N.M. and Pavlenko, E.A., 2023. Regional Features of Water Density Stratification and Internal Wave Characteristics in the Arctic Seas. Physical Oceanography, 30(6), pp. 731-746.
  23. Ivanov, V.V., Frolov, I.E. and Filchuk, K.V., 2020. Transformation of Atlantic Water in the North-Eastern Barents Sea in Winter. Arctic and Antarctic Research, 66(3), pp. 246-266. https://doi.org/10.30758/0555-2648-2020-66-3-246-266
  24. Viazilova, A.E., Alekseev, G.V., Balakin, A.A. and Smirnov, A.V., 2015. Influence of the Arctic on Salinity Anomaly Formation in the North-West Atlantic and North European Basin. Arctic and Antarctic Research, (3), pp. 39-50 (in Russian).

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