Spring thermocline formation in the coastal zone of the southeastern Baltic Sea based on field data in 2010–2013
- Authors: Chubarenko I.P.1, Demchenko N.Y.1, Esiukova E.E.1, Lobchuk O.I.1, Karmanov K.V.1, Pilipchuk V.A.1, Isachenko I.A.1, Kuleshov A.F.1, Chugaevich V.Y.1, Stepanova N.B.1, Krechik V.A.1, Bagaev A.V.1
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Affiliations:
- Atlantic Branch, Shirshov Institute of Oceanology
- Issue: Vol 57, No 5 (2017)
- Pages: 632-638
- Section: Marine Physics
- URL: https://bakhtiniada.ru/0001-4370/article/view/149513
- DOI: https://doi.org/10.1134/S000143701705006X
- ID: 149513
Cite item
Abstract
The transition from winter vertical mixing to the formation of the spring thermocline in the southeastern Baltic Sea is studied based on data from the hydrophysical measurements program (11 expeditions) in the Russian part of Gdansk Bay in March–June 2010, 2011, and 2013. CTD measurements were taken along the standard 18-km transect across the isobaths with a 500-m step abeam the city of Baltiysk. A set of frequently measured data was collected in a 1–2 week interval from the end of March to the beginning of May, which made it possible to analyze the transformation of the vertical thermal structure of water from inverse winter type to the summer stratification with the transition of temperature over the temperature of the density maximum. Series of repeated measurements at the deep and coastal stations as well as surface and subsurface towed measurements were carried out. The fact that lenses of freshened warmer water appear at the surface almost simultaneously with intensification of cold intrusions in intermediate (10–40 m) layers makes it possible not only to confirm the advective nature of the formation of the spring thermocline in the Baltic Sea, but also to hypothesize about the intensification of intrabasin exchange when winter-time vertical mixing ceases: the potential energy excess supported by vertical mixing in the 60-m upper quasi-homogeneous layer (UQL) of the Baltic Proper, in which the horizontal estuarine salinity gradient is significant, is converted to kinetic energy of exchange currents as the mixing process terminates. Such water dynamics makes it possible to explain the intensification of intrusions in the Baltic in spring and the formation of the cold intermediate layer due to the fast propagation of late-winter UQL water from the Bornholm Basin to the Baltic Proper. The results agree well with earlier published studies of other authors.
About the authors
I. P. Chubarenko
Atlantic Branch, Shirshov Institute of Oceanology
Author for correspondence.
Email: irina_chubarenko@mail.ru
Russian Federation, Kaliningrad
N. Yu. Demchenko
Atlantic Branch, Shirshov Institute of Oceanology
Email: irina_chubarenko@mail.ru
Russian Federation, Kaliningrad
E. E. Esiukova
Atlantic Branch, Shirshov Institute of Oceanology
Email: irina_chubarenko@mail.ru
Russian Federation, Kaliningrad
O. I. Lobchuk
Atlantic Branch, Shirshov Institute of Oceanology
Email: irina_chubarenko@mail.ru
Russian Federation, Kaliningrad
K. V. Karmanov
Atlantic Branch, Shirshov Institute of Oceanology
Email: irina_chubarenko@mail.ru
Russian Federation, Kaliningrad
V. A. Pilipchuk
Atlantic Branch, Shirshov Institute of Oceanology
Email: irina_chubarenko@mail.ru
Russian Federation, Kaliningrad
I. A. Isachenko
Atlantic Branch, Shirshov Institute of Oceanology
Email: irina_chubarenko@mail.ru
Russian Federation, Kaliningrad
A. F. Kuleshov
Atlantic Branch, Shirshov Institute of Oceanology
Email: irina_chubarenko@mail.ru
Russian Federation, Kaliningrad
V. Ya. Chugaevich
Atlantic Branch, Shirshov Institute of Oceanology
Email: irina_chubarenko@mail.ru
Russian Federation, Kaliningrad
N. B. Stepanova
Atlantic Branch, Shirshov Institute of Oceanology
Email: irina_chubarenko@mail.ru
Russian Federation, Kaliningrad
V. A. Krechik
Atlantic Branch, Shirshov Institute of Oceanology
Email: irina_chubarenko@mail.ru
Russian Federation, Kaliningrad
A. V. Bagaev
Atlantic Branch, Shirshov Institute of Oceanology
Email: irina_chubarenko@mail.ru
Russian Federation, Kaliningrad
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