Mesoscale Variability of the Ocean in the Northern Part of the Weddell Sea

Oceanology - Results of a mesoscale survey in the Powell Basin in the northern part of the Weddell Sea are analyzed. The survey included 24 CTD casts (6 × 4) with an interval of six nautical...     

Structure and Distribution of Autumn Zooplankton in the Southeastern Baltic Sea in 2015

Oceanology - Specific features of the structure and distribution of autumn zooplankton in the southeastern Baltic Sea (SEB) in October 2015 have been found taking into account the hydrological and...     

Peculiarities of Water Circulation in the Central Part of the Bransfield Strait in January 2020

Doklady Earth Sciences - The results of measurement of the thermohaline parameters of water and currents in the Bransfield Strait in Antarctica during the expedition of the Shirshov Institute of...     

Oceanological Research in the Baltic Sea during the 56th Cruise of the Passenger Vessel Akademik Ioffe

Oceanology - During the 56th cruise of the P/V Akademik Ioffe (August 2020) in the Baltic Sea, hypoxia was registered at a water depth of 80 m, hydrogen sulfide in the East Gotland Basin was...     

Currents in the Western Part of the Weddell Sea and Drift of Large Iceberg A68A

Oceanology - The drift of the large (length 160 km, area 5800 km2) A68A iceberg in the western part of the Weddell Sea is considered. Analysis was carried out on the basis of satellite images and...     

Spring thermocline formation in the coastal zone of the southeastern Baltic Sea based on field data in 2010–2013

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.     

Influence of Abiotic Environmental Factors on the Abundance of Cod Eggs and Cod Larvae in the Southeastern Baltic Sea in 2016

Oceanology - The characteristics of the abiotic environmental parameters obtained during in situ observations and significant for the survival of cod eggs and larvae (water salinity, water...     

Water dynamics above the sloping bottom due to an intense summer heating

Considered is the water exchange in the coastal zone of natural reservoirs induced as a result of the differential heating of water above the sloping bottom. The laboratory experiment data and the constructed simple analytic model demonstrate that the main reason for the motions is the hydrostatic pressure difference in the area above the slope. It is demonstrated for different types of vertical stratification that the pressure difference maximum is reached at the depth of about 0.4D (D is the depth of the heated layer in the deep part). The respective current is directed to the shore and is a driving element of the whole circulation of water including its forced ascend along the slope, the free surface level increase, and the formation of the compensatory offshore current in the upper layers. The analysis of in situ observational data in the coastal zone of the Baltic Sea at the intensive heating in July 2006 corroborates the obtained regularities indicating that the coastal heating favors the formation of upwelling along the slope.     

Oceanological Research of the Baltic Sea in the 51st Cruise of the PV Akademik Sergey Vavilov (June–July 2021)

Oceanology - The 51st cruise of the PV Akademik Sergey Vavilov (June 30–July 14, 2021) included the study of redox conditions in the Baltic Sea deeps. Water temperature in the upper...     

Integrated Oceanographic Research of Discovery Gap (Eastern North Atlantic) during the Cruise 43 of the R/V Akademik Nikolaj Strakhov

Oceanology - During cruise 43 of the R/V Akademik Nikolaj Strakhov (September 21–October 9, 2019), new data were obtained on the bottom relief, sedimentation, and hydrological regime of the...