Oceanologia No. 57 (2) / 15


Original research article

Original research article

Barycenter reflected equatorial Pacific sea level structure evolution and its indication of ENSO events
Oceanologia 2015, 57(2), 107-115

Wen Luo1,3, Lin Yi1,2,*, Hui Sun1, Linwang Yuan1,2
1Key Laboratory of Virtual Geographic Environment, Ministry of Education, Nanjing Normal University,
Nanjing, PR China
2Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application,
Nanjing, PR China; *corresponding author
e-mail: yuzhaoyuan@njnu.edu.cn
3Geography Department, University of Wisconsin-Madison,
Madison, United States

keywords: Sea level changes; ENSO; Equatorial Pacific; Satellite altimetry; Principal tensor analysis; Barycenter method

Received 18 October 2014, accepted 23 January 2015. Available online 18 February 2015

This work was supported by the NSCF Project (Grant Nos. 41201377 and 41471319) and the PAPD program.


Focused on the zonal and meridional response of sea level change to El Niño-Southern Oscillation (ENSO) events, this paper retrieves the overall average, positive anomaly and negative anomaly sea surface height (SSH) series of equatorial Pacific area (EPA) from satellite altimetry data from 1993 to 2013. The barycenter method is then applied to each of the three series to get the zonal and meridional barycenter coordinates. The barycenter coordinates are then compared with the Multivariate ENSO index (MEI) to reveal the zonal and meridional response of sea level change to ENSO. The meridional and zonal spatio-temporal evolutionary processes of sea level change in EPA during different ENSO events are reconstructed by the Principle Tensor Analysis of Rank 3 Method (PTA3). Comparative analysis shows that the meridional change of positive anomalies barycenter, rather than the mean series of sea level height anomaly in EPA, can well characterize the intensity and evolutionary process of ENSO events. Meanwhile, the zonal migration of barycenter may reflect the lag adjustment of the sea level to the ENSO signal. The analysis on the meridional and zonal evolution of the sea level change in different ENSO periods shows that the response of sea level change to the ENSO events can be mainly characterized by the position differences between positive and negative sea level anomaly barycenter, SSH gradient in the meridional direction and the inconsistency in the overall spatial structure and temporal evolution characteristics in the zonal direction.
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Modelling the water and heat balances of the Mediterranean Sea using a two-basin model and available meteorological, hydrological, and ocean data
Oceanologia 2015, 57(2), 116-131

Mohamed Shaltout1,2,*, , Anders Omstedt2
1Department of Oceanography, University of Alexandria, Faculty of Science,
Alexandria, Egypt;
*corresponding author
e-mail: mohamed.shaltot@alexu.edu.eg
2 Department of Earth Sciences, University of Gothenburg,
Goteborg, Sweden

keywords: Mediterranean Sea; Water budget; Heat budget; Gibraltar Strait; Sicily Channel; Climate change

Received 27 October 2014, accepted 6 November 2014. Available online November 2014

This research was undertaken when Dr. Mohamed Shaltout was a visiting scientist at the Ocean Climate Group, Department of Earth Sciences, University of Gothenburg, Sweden. The work is a contribution to the GEWEX/BALTEX phase II and the newly formed programme “Baltic Earth-Earth System Science for the Baltic Sea region” and the HyMex program.


This paper presents a two-basin model of the water and heat balances of the Western and Eastern Mediterranean sub-basins (WMB and EMB, respectively) over the 1958–2010 period using available meteorological and hydrological data. The results indicate that the simulated temperature and salinity in both studied Mediterranean sub-basins closely follow the reanalysed data. In addition, simulated surface water in the EMB had a higher mean temperature (by approximately 1.6°C) and was more saline (by approximately 0.87 g kg−1) than in the WMB over the studied period. The net evaporation over the EMB (1.52 mm day−1) was approximately 1.7 times greater than over the WMB (0.88 mm day−1). The water balance of the Mediterranean Sea was controlled by net inflow through the Gibraltar Strait and Sicily Channel, the net evaporation rate and freshwater input. The heat balance simulations indicated that the heat loss from the water body was nearly balanced by the solar radiation to the water body, resulting in a net export (import) of approximately 13 (11) W m−2 of heat from the WMB (to the EMB).
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Variability of currents over the southern slope of the Gulf of Finland
Oceanologia 2015, 57(2), 132-143

Irina Suhhova*, , Juss Pavelson, Priidik Lagemaa
Marine Systems Institute at Tallinn University of Technology,
Tallinn, Estonia;
*corresponding author
e-mail: irina.suhhova@msi.ttu.ee

keywords: Slope current; Stratification; Up-/downwelling; The Gulf of Finland

Received 27 November 2014, accepted 19 January 2015. Avaiable online 29 January 2015

This study was supported by the Estonian Science Foundation Grant 9381 and institutional research funding IUT19-6 of the Estonian Ministry of Education and Research.


In our intraseasonal variability studies of currents in the coastal sea of the Gulf of Finland northeast of Pakri Peninsula, we compared the observation data from a bottom-mounted ADCP (March–June of 2009, 50 m depth) with the simulation data from High Resolution Operational Model of the Baltic (HIROMB). The structure of the current pattern appeared strongly dependent on the stratification conditions. The flow was quasi-barotropic during the periods of weak inverse thermal stratification at the end of winter season and at transition from the inverse thermal stratification to summer type stratification when the sea was thermally unstratified, but mostly two-layered (baroclinic) when the summer type thermal stratification had developed. The alternation of strong westward (eastward) currents (up to 30 cm s−1) in the upper layer is explained in terms of coastal upwelling (downwelling) due to favourable background winds. The measured and the modelled upper layers along isobath currents showed a noticeable correlation with the correlation coefficient of 0.52 and 0.82 during the periods of winter type and summer type stratifications, respectively, and the absence of a significant correlation during the transition period. The eastward (upwind) current episodes with speeds reaching 18 cm s−1 below the seasonal thermocline are likely to reflect the specific circulation response in the elongated basin caused by the easterly wind. The long-term mean (over 3.5 months) current vector (−2.0 cm s−1, −2.9 cm s−1) was westward in the upper sea and eastward, nearly along isobaths (1.1 cm s−1, −0.3 cm s−1) in the deeper layers.
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Morpholithodynamical changes of the beach and the nearshore zone under the impact of submerged breakwaters – a case study (Orłowo Cliff, the Southern Baltic)
Oceanologia 2015, 57(2), 144-158

Agnieszka Kubowicz-Grajewska
Department of Marine Geology, Institute of Oceanography, University of Gdańsk,
Gdynia, Poland;
e-mail: oceakg@univ.gda.pl

keywords: Submerged breakwaters (SBWs); Morpholithodynamics; Orłowo Cliff

Received 31 August 2014, accepted 27 January 2015. Available online 9 February 2015

The reported study was supported by RFBR, research project no. 12-05-00240 a.The results presented in this paper come from the doctoral thesis: “The influence of submerged breakwaters in the region of Orłowo Cliff on morpholithodynamics of the coastal zone”.


Submerged breakwaters (SBWs) were used for the first time on the Polish coast in 2006, in the western coast of Gdańsk Bay, in the area of Orłowo Cliff. They were built to prevent the abrasion and inundation of areas situated in the hinterland, especially in the conditions of storm surges. The main objective of the study was to determine their effect on the morphology and grain size composition in the seashore and nearshore zone.
Based on the conducted research and analysis, it has been found that the construction has a minor impact on the modification of the shore and nearshore zone morpholithodynamics, which is evidenced by a sinuate shape of the shoreline and a relatively stable cape in the central part of the area, present both before (1966–2005) and after SBWs were built. Furthermore, the progressive abrasion, the lack of significant changes in the morphology and particle size distribution of the beach and the nearshore zone, as well as the fact that those changes are limited only to the immediate surroundings of the submerged breakwaters prove their neutral impact.
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Spectrophotometric studies of marine surfactants in the southern Baltic Sea
Oceanologia 2015, 57(2), 159-167

Violetta Drozdowska*,1, Marek Józefowicz2
1Institute of Oceanology, Polish Academy of Sciences,
Sopot, Poland;
*corresponding author
e-mail: drozd@iopan.gda.pl
2 Institute of Experimental Physics, University of Gdańsk,
Gdańsk, Poland

keywords: Marine surfactant; Chromophoric dissolved organic matter (CDOM); Fluorophoric dissolved organic matter (FDOM); Photometry; Fluorometry; Baltic Sea

Received 25 September 2014, accepted 30 December 2014. Available online 9 February 2015

Support for this study was partly provided by the project ‘Satellite Monitoring of the Baltic Sea Environment – SatBałtyk’ funded by European Union through European Regional Development Fund contract no. POIG 01.01.02-22-011/09.


It is well known that surfactants in the southern Baltic Sea constitute the organic matter from riverine waters discharges as well as the secondary degradation products of marine phytoplankton excretion. They reach the surface microlayer by the upwellings and turbulent motions of water and in the membranes of the vesicles as well as from the atmosphere. To assess concentration and spatial distribution of marine surfactants in the southern Baltic Sea, the steady-state spectrophotometric and spectrofluorometric measurements of water samples taken from a surface film and a depth of 0.5 m were carried out. Water samples were collected during windless days of the cruise of r/v ‘Oceania’ in November 2012, from the open and the coastal waters having regard to the vicinity of the Vistula and Łeba mouths. In the present paper, fractions of dissolved organic matter having chromophores (CDOM) or fluorophores (FDOM) are recognized through their specific spectroscopic behavior, i.e., steady-state absorption, fluorescence excitation and fluorescence spectra. The steady-state spectroscopic measurements revealed the CDOM and FDOM molecules characteristic to both the land and marine origin. Moreover, the concentration and spatial distribution of marine surfactants significantly depend on the distance from the river mouth. Finally, higher values of absorbance and fluorescence intensity observed in a surface film in comparison to these values in a depth of 0.5 m clearly suggest the higher concentration of organic matter in a marine film. On the other hand, our results revealed that a surface microlayer is composed of the same CDOM and FDOM as bulk water.
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DOC and POC in the southern Baltic Sea. Part II – Evaluation of factors affecting organic matter concentrations using multivariate statistical methods
Oceanologia 2015, 57(2), 168-176

Anna Maciejewska, Janusz Pempkowiak*
Marine Chemistry and Biochemistry Department, Institute of Oceanology, Polish Academy of Sciences,
Sopot, Poland;
e-mail: aninamac@iopan.gda.pl
* corresponding author
e-mail: pempa@iopan.gda.pl

keywords: Southern Baltic; Organic carbon sources; Quantitative contribution; Biological activity; Abiotic factors; Cluster analysis (CA); Principal component analysis (PCA); Segment analysis

Received 30 June 2014, accepted 17 November 2014. Available online 8 December 2014

This study was supported by the Baltic-C a BONUS Plus EUFP6 Project, statutory activities of Institute of Oceanology PAN, Sopot, and the Polish Ministry of Science and Higher Education, Grant No. N N306 404338.


This study is a continuation of the research on organic matter sources, distribution and dynamics in the southern Baltic Sea described in detail by Maciejewska and Pempkowiak (2014).
In this paper, cluster analysis, principal component analysis and segment analysis were used to assess relations among factors influencing organic matter concentration in the Baltic sea-water. The following sea-water properties, salinity (Sal), temperature (Temp), pH, concentrations of chlorophyll a (Chla) and phaeopigment a (Feo), were assessed, while dissolved (DOC) and particulate (POC) organic carbon were used as organic matter measures. Water samples were collected in the course of a three-year study (2009–2011) from the Gdańsk Deep, the Gotland Deep and the Bornholm Deep (Southern Baltic).
As a result, relations among both DOC and POC and the measured water properties were revealed. The cluster analysis leads to the discovery of the following structure of the analyzed water properties: DOC-pH, POC-Chla, without providing interpretation why the structure exists. Using the principal component analysis, factors influencing DOC and POC concentrations were classified as plankton activity and the inflows of saline and freshwater water masses as the study area. Segment regression analysis revealed that organic matter consists of labile and stable fractions and led to the quantification of relations between DOC and the measured sea-water properties. The following contributions to the DOC fluctuations were calculated: salinity – 11%, chlorophyll a – 26%, phaeopigment a – 26%, POC – 38% in the growing season and 31%, 33%, 21% and 22% respectively in the non-growing season.
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Water type quantification in the Skagerrak, the Kattegat and off the Jutland west coast
Oceanologia 2015, 57(2), 177-195

Trond Kristiansen1, Eyvind Aas2,*
1Institute of Marine Research,
Bergen, Norway,
2 Department of Geosciences, University of Oslo,
Oslo, Norway;
*corresponding author
e-mail: eyvind.aas@geo.uio.no

keywords: German Bight; Kattegat; Skagerrak; Water types; CDOM

Received 1 September 2014, accepted 17 November 2014. Available online 6 December 2014


An extensive data series of salinity, nutrients and coloured dissolved organic material (CDOM) was collected in the Skagerrak, the northern part of the Kattegat and off the Jutland west coast in April each year during the period 1996–2000, by the Institute of Marine Research in Norway. In this month, after the spring bloom, German Bight Water differs from its surrounding waters by a higher nitrate content and higher nitrate/phosphate and nitrate/silicate ratios. The spreading of this water type into the Skagerrak is of special interest with regard to toxic algal blooms. The quantification of the spatial distributions of the different water types required the development of a new algorithm for the area containing the Norwegian Coastal Current, while an earlier Danish algorithm was applied for the rest of the area. From the upper 50 m a total of 2227 observations of salinity and CDOM content have been used to calculate the mean concentration of water from the German Bight, the North Sea (Atlantic water), the Baltic Sea and Norwegian rivers. The Atlantic Water was the dominant water type, with a mean concentration of 79%, German Bight Water constituted 11%, Baltic Water 8%, and Norwegian River Water 2%. At the surface the mean percentages of these water types were found to be 68%, 15%, 15%, and 3%, respectively. Within the northern part of the Skagerrak, closer to the Norwegian coast, the surface waters were estimated to consist of 74% Atlantic Water, 20% Baltic Water, and 7% Norwegian River Water. The analysis indicates that the content of German Bight Water in this part is less than 5%.
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Comparison of PCBs and PAHs levels in European coastal waters using mussels from the Mytilus edulis complex as biomonitors: Production and mortality rates
Oceanologia 2015, 57(2), 196-211

Michał Olenycz*,1, Adam Sokołowski1, Agnieszka Niewińska1, Maciej Wołowicz1, Jacek Namieśnik2, Herman Hummel3, Jeroen Jansen4
1University of Gdańsk, Institute of Oceanography,
Gdynia, Poland;
*corresponding author
e-mail: molenycz@im.gda.pl
2Chemical Faculty, Gdańsk University of Technology,
Gdańsk, Poland
3Netherlands Institute of Ecology, Centre for Estuarine and Marine Ecology,
Yerseke, The Netherlands
Den Helder, The Netherlands

keywords: PCBs; PAHs; Biomonitoring; Mussels; European coastal waters; Pollution

Received 31 July 2014, accepted 30 December 2014. Available online 14 January 2015

This work was supported by the European Community, RTD project “The impact of biodiversity changes in coastal marine benthic ecosystems” (BIOCOMBE; EVK3-CT-2002-00072), ARI project “Sandgerdi Marine Centre” (SMC; HPRI-CT-2002-00193) and by internal grant BW/13A0-5-0272-8 for A.S./Adam Sokołowski from the University of Gdańsk.


Mussels from the Mytilus edulis complex were used as biomonitors for two groups of organic pollutants: polychlorinated biphenyls (PCBs, congeners: 28, 52, 101, 118, 138, 153 and 180) and polycyclic aromatic hydrocarbons (PAHs, naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benz(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, indeno(1,2,3-cd)pyrene, dibenz(a,h)anthracene, benzo(g,h,i)perylene) at 17 sampling sites to assess their relative bioavailabilities in coastal waters around Europe. Because of the temporal differences in PCBs and PAHs concentrations, data were adjusted using Seasonal Variation Coefficients (SVC) before making large-scale spatial comparisons. The highest concentrations of PCBs were found near estuaries of large rivers flowing through urban areas and industrial regions. Elevated bioavailabilities of PAHs occurred in the vicinity of large harbors, urban areas, and regions affected by petroleum pollution as well as in some remote locations, which indicated long-range atmospheric deposition.
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Deep water masses in the Iceland Basin during the Last Interglacial (MIS 5e): Evidence from benthic foraminiferal data
Oceanologia 2015, 57(2), 212-221

Nadezhda P. Lukashina1, Leyla D. Bashirova1,2,*
1The Atlantic Branch of the P.P. Shirshov Institute of Oceanology of the Russian Academy of Sciences (ABIORAS),
Kaliningrad, Russia,
2 Immanuel Kant Baltic Federal University,
Kaliningrad, Russia,
*corresponding author
e-mail: bas_leila@mail.ru

keywords: Holocene; Last Interglacial; Paleoceanography; Deep water circulation; Benthic foraminifera

Received 9 August 2014, Accepted 20 August 2014, Available online 22 October 2014

The reported study was supported by RFBR, research project no. 12-05-00240 a.


The Last Interglacial period, marine isotope stage (MIS) 5e, is a potential analogue for the Holocene. In this study, we investigated a marine sediment core, AMK-4442, recovered from the northern part of the Iceland Basin. The multiproxy approach used in this study, which includes foraminiferal and lithological analyses, identifies the difference in intensity of deep circulation between MIS 5e and the Holocene. Our data indicate that during early MIS 5e, the Iceland-Scotland Overflow Water (ISOW) flux into the Iceland Basin was suppressed. We suggest that the less active North Atlantic Deep Water (NADW) formation at this time was related to the obstruction of warm surface water inflow into the Nordic Seas.
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