Entity

Time filter

Source Type


Atamanchuk D.,Gothenburg University | Kononets M.,Gothenburg University | Thomas P.J.,Christian Michelsen Research | Hovdenes J.,Aanderaa Data Instruments AS | And 3 more authors.
Journal of Marine Systems | Year: 2015

A cabled underwater observatory with more than 30 sensors delivering data in real-time was used to study the dynamics of the upper pelagic carbonate system of the Koljo Fjord, western Sweden, from September to April during two consecutive years (2011-2012 and 2012-2013). In the dynamic upper ca 15m of the water column, salinity and temperature varied by up to 10 and 20°C throughout the recorded periods, respectively. Partial pressure of CO2 (pCO2), measured with newly developed optical sensors (optodes) at three water depths (5, 9.6 and 12.6m), varied between 210-940μatm, while O2 varied between 80-470μmol/L. Redfield scaled graphs (δO2:δDIC=-1.30), in which DIC was derived from pH or pCO2 and salinity-derived alkalinity (ATsal), and oxygen was measured by the sensors, were used as a tool to assess timing and occurrence of different processes influencing the dynamics of these parameters. Distinctive short-term variations of pCO2 and O2 were induced by either tidal oscillations, wind-driven water mass transport in the mixed layer or occasional transport of deep-basin water from below the thermo/halocline to the surface layer. Intensified air-sea gas exchange during short storm events was usually followed by stabilization of gas-related parameters in the water column, such as O2 concentration and pCO2, on longer time-scales characteristic for each parameter. Biological processes including organic matter degradation in late summer/autumn and primary production in early spring were responsible for slower and gradual seasonal changes of pCO2 and O2. Net primary production (NPP) rates in the Koljo Fjord were quantified to be 1.79 and 2.10gCm-2 during the spring bloom periods in 2012 and 2013, respectively, and ratios of O2 production:DIC consumption during the same periods were estimated to be -1.21±0.02 (at 5m depth in 2013), -1.51±0.02 (at 12.6m in 2012) and -1.95±0.05 (at 9.6m in 2013). These ratios are discussed and compared to previously reported O2:C ratios during primary production. © 2015 Elsevier B.V. Source


Atamanchuk D.,Gothenburg University | Tengberg A.,Gothenburg University | Tengberg A.,Aanderaa Data Instruments AS | Thomas P.J.,Christian Michelsen Research | And 4 more authors.
Limnology and Oceanography: Methods | Year: 2014

This article reports the performance of an improved, newly developed, compact, low power, lifetime-based optical sensor (optode) for measuring partial pressure of dissolved CO2 gas (pCO2) in natural waters. The results suggest that after preconditioning, these sensors are stable in water for time periods longer than 7 months. The wide dynamic range of about 0-50000 μatm opens possibilities for numerous applications of which some are presented. In normal marine environments with pCO2 levels of 200-1000 μatm, the best-obtained precision was about ±2 μatm, and the absolute accuracy was between 2-75 μatm, depending on the deployment and the quality of the collected reference water samples. One limitation is that these sensors will become irreversibly poisoned by H2S and should thus not be deployed in sulphidic environments. © 2014, by the American Society of Limnology and Oceanography, Inc. Source


Reichel M.,Centrum Techniki Okretowej S.A | Abramowicz-Gerigk T.,Maritime Academy of Gdynia | Burciu Z.,Maritime Academy of Gdynia | Burka M.,Sprint S.A | And 9 more authors.
Australian Coasts and Ports 2015 Conference | Year: 2015

Safeport: on-board visualization of hydro-meteorological effects on ferries entering and berthing the Port of Gdynia, Poland. The end product of Safeport is ship adapted visualization software, presented on the ferry bridge, which gives recommendations on the safest harbor approach taking into account prevailing hydro-meteorological conditions. Main system components include a dynamic model assimilating real time hydro-meteorological data and ship specific wind-current response information. Safeport is a joint project between Polish (Gdynia Maritime University, Port of Gdynia Authority S.A., Ship Design and Research Centre S.A and Sprint Sp.Z.) And Norwegian partners (Aanderaa Data Instruments A/S and NIVA) running over a time period of 3 years from 2010-2012. The overall goal of the project were to improve the safety during approach, entering and berthing of large ships (e.g. ferries) in ports and harbors. Gdynia harbor, one of the largest in the Baltic Sea, and the bay of Gdansk was selected as the major test site for this project. The main task for the Norwegian partners (Aanderaa and NIVA) was: Computer modelling of physical conditions (winds, waves, currents, water level and density) in and around the Gdynia harbor. To calibrate and validate the model multiple instruments were deployed in the area. The output is a dynamic model that needs continuous input of wind data from a weather station installed in the frames of Safeport. With this information the model can predict wind and currents in the entire bay as well as just outside and in the harbor. Source


Tengberg A.,Aanderaa Data Instruments AS | Waldmann C.,University of Bremen | Hall P.O.J.,Gothenburg University | Atamanchuk D.,Gothenburg University | Kononets M.,Gothenburg University
OCEANS 2013 MTS/IEEE Bergen: The Challenges of the Northern Dimension | Year: 2013

Decades of technical development in electronics, telecommunication, optics and acoustics measuring techniques have opened new possibilities for multi-parameter monitoring of the marine environment. This conference paper will give examples on how fixed multi-parameter platforms are used in a wide variety of applications ranging from shallow coastal on-line observatories down to measuring in the deepest Ocean trenches. Focus will be on long-term (years) stability and the challenge to maintain satisfactory quality control throughout the deployments. © 2013 IEEE. Source


Atamanchuk D.,Gothenburg University | Tengberg A.,Gothenburg University | Tengberg A.,Aanderaa Data Instruments AS | Aleynik D.,Scottish Association for Marine Science | And 6 more authors.
International Journal of Greenhouse Gas Control | Year: 2014

This work is focused on results from a recent controlled sub-seabed in situ carbon dioxide (CO2) release experiment carried out during May-October 2012 in Ardmucknish Bay on the Scottish west coast. Three types of pCO2 sensors (fluorescence, NDIR and ISFET-based technologies) were used in combination with multiparameter instruments measuring oxygen, temperature, salinity and currents in the water column at the epicentre of release and further away. It was shown that distribution of seafloor CO2 emissions features high spatial and temporal heterogeneity. The highest pCO2 values (~1250μatm) were detected at low tide around a bubble stream and within centimetres distance from the seafloor. Further up in the water column, 30-100cm above the seabed, the gradients decreased, but continued to indicate elevated pCO2 at the epicentre of release throughout the injection campaign with the peak values between 400 and 740μatm. High-frequency parallel measurements from two instruments placed within 1m from each other, relocation of one of the instruments at the release site and 2D horizontal mapping of the release and control sites confirmed a localized impact from CO2 emissions. Observed effects on the water column were temporary and post-injection recovery took <7 days.A multivariate statistical approach was used to recognize the periods when the system was dominated by natural forcing with strong correlation between variation in pCO2 and O2, and when it was influenced by purposefully released CO2.Use of a hydrodynamic circulation model, calibrated with in situ data, was crucial to establishing background conditions in this complex and dynamic shallow water system. © 2014 Elsevier Ltd. Source

Discover hidden collaborations