| 1. |
- Abrahamsson, Katarina, 1957, et al.
(author)
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Variations of biochemical parameters along a transect in the Southern Ocean, with special emphasis on volatile halogenated organic compounds
- 2004
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In: Deep-sea research. Part II, Topical studies in oceanography. - : Elsevier BV. - 0967-0645. ; 51:22-24, s. 2745-2756
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Journal article (peer-reviewed)abstract
- A number of parameters of biogeochemical interest were monitored along a north-southerly transect (S 43-S 63degrees) in the Atlantic Sector of the Southern Ocean from the 8th to the 20th of December 1997. Changes in total dissolved inorganic carbon (C-T) and total alkalinity (A(T)) were mostly dependent on temperature and salinity until the ice edge was reached. After this point only a weak correlation was seen between these. Highest mean values of C-T and A(T) were observed in the Winter Ice Edge (WIE) (2195 and 2319 mumol kg(-1), respectively). Lowest mean AT (2277 mumol kg(-1)) was observed in the Sub-Antarctic Front (SAF), whereas lowest mean CT concentration (2068 mumol kg(-1)) was associated with the Sub-Tropical Front (STF). The pH in situ varied between 8.060 and 8.156 where the highest values were observed in the southern part of the Antarctic Polar Front (APF) and in the Summer Ice Edge (SIE) Region. These peaks were associated with areas of high chlorophyll a (chl a) and tribromomethane values. In the other areas the pH in situ was mainly dependent on hydrography. Bacterial abundance decreased more than one order of magnitude when going from north to south. The decrease appeared to be strongly related to water temperature and there were no elevated abundances at frontal zones. Microphytoplankton dominated in the SAF and APF, whereas the nano- and picoplankton dominated outside these regions. Volatile halogenated compounds were found to vary both with regions, and with daylight. For the iodinated compounds, the highest concentrations were found north of the STF. Brominated hydrocarbons had high concentrations in the STF, but elevated concentrations were also found in the APF and SIE regions. No obvious correlation could be found between the occurrence of individual halocarbons and chl a. On some occasions trichloroethene and tribromomethane related to the presence of nano- and microplankton, respectively.
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| 2. |
- Bakker, D. C. E., et al.
(author)
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A multi-decade record of high-quality fCO(2) data in version 3 of the Surface Ocean CO2 Atlas (SOCAT)
- 2016
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In: Earth System Science Data. - : Copernicus GmbH. - 1866-3508 .- 1866-3516. ; 8:2, s. 383-413
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Journal article (peer-reviewed)abstract
- The Surface Ocean CO2 Atlas (SOCAT) is a synthesis of quality-controlled fCO(2) (fugacity of carbon dioxide) values for the global surface oceans and coastal seas with regular updates. Version 3 of SOCAT has 14.7 million fCO(2) values from 3646 data sets covering the years 1957 to 2014. This latest version has an additional 4.6 million fCO(2) values relative to version 2 and extends the record from 2011 to 2014. Version 3 also significantly increases the data availability for 2005 to 2013. SOCAT has an average of approximately 1.2 million surface water fCO(2) values per year for the years 2006 to 2012. Quality and documentation of the data has improved. A new feature is the data set quality control (QC) flag of E for data from alternative sensors and platforms. The accuracy of surface water fCO(2) has been defined for all data set QC flags. Automated range checking has been carried out for all data sets during their upload into SOCAT. The upgrade of the interactive Data Set Viewer (previously known as the Cruise Data Viewer) allows better interrogation of the SOCAT data collection and rapid creation of high-quality figures for scientific presentations. Automated data upload has been launched for version 4 and will enable more frequent SOCAT releases in the future. High-profile scientific applications of SOCAT include quantification of the ocean sink for atmospheric carbon dioxide and its long-term variation, detection of ocean acidification, as well as evaluation of coupled-climate and ocean-only biogeochemical models. Users of SOCAT data products are urged to acknowledge the contribution of data providers, as stated in the SOCAT Fair Data Use Statement. This ESSD (Earth System Science Data) "living data" publication documents the methods and data sets used for the assembly of this new version of the SOCAT data collection and compares these with those used for earlier versions of the data collection (Pfeil et al., 2013; Sabine et al., 2013; Bakker et al., 2014).Individual data set files, included in the synthesis product, can be downloaded here: doi:10.1594/PANGAEA.849770. The gridded products are available here: doi: 10.3334/CDIAC/OTG.SOCAT_V3_GRID.
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| 3. |
- Bakker, D. C. E., et al.
(author)
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An update to the surface ocean CO2 atlas (SOCAT version 2)
- 2014
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In: Earth System Science Data. - : Copernicus GmbH. - 1866-3508 .- 1866-3516. ; 6:1, s. 69-90
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Journal article (peer-reviewed)abstract
- The Surface Ocean CO2 Atlas (SOCAT), an activity of the international marine carbon research community, provides access to synthesis and gridded fCO2 (fugacity of carbon dioxide) products for the surface oceans. Version 2 of SOCAT is an update of the previous release (version 1) with more data (increased from 6.3 million to 10.1 million surface water fCO 2 values) and extended data coverage (from 1968-2007 to 1968-2011). The quality control criteria, while identical in both versions, have been applied more strictly in version 2 than in version 1. The SOCAT website (http://www.socat.info/) has links to quality control comments, metadata, individual data set files, and synthesis and gridded data products. Interactive online tools allow visitors to explore the richness of the data. Applications of SOCAT include process studies, quantification of the ocean carbon sink and its spatial, seasonal, year-to-year and longerterm variation, as well as initialisation or validation of ocean carbon models and coupled climate-carbon models. © Author(s) 2014. CC Attribution 3.0 License.
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| 4. |
- Charrieau, Laurie M., et al.
(author)
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The effects of multiple stressors on the distribution of coastal benthic foraminifera: A case study from the Skagerrak-Baltic Sea region
- 2018
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In: Marine Micropaleontology. - : Elsevier BV. - 0377-8398. ; 139, s. 42-56
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Journal article (peer-reviewed)abstract
- Coastal ecosystems are subjected to both large natural variability and increasing anthropogenic impact on environmental parameters such as changes in salinity, temperature, and pH. This study documents the distribution of living benthic foraminifera under the influence of multiple environmental stressors in the Skagerrak-Baltic Sea region. Sediment core tops were studied at five sites along a transect from the Skagerrak to the Baltic Sea, with strong environmental gradients, especially in terms of salinity, pH, calcium carbonate saturation and dissolved oxygen concentration in the bottom water and pore water. We found that living foraminiferal densities and species richness were higher at the Skagerrak station, where the general living conditions were relatively beneficial for Foraminifera, with higher salinity and Ωcalc in the water column and higher pH and oxygen concentration in the bottom and pore water. The most common species reported at each station reflect the differences in the environmental conditions between the stations. The dominant species were Cassidulina laevigata and Hyalinea balthica in the Skagerrak, Stainforthia fusiformis, Nonionella aff. stella and Nonionoides turgida in the Kattegat and N. aff. stella and Nonionellina labradorica in the Öresund. The most adverse conditions, such as low salinity, low Ωcalc, low dissolved oxygen concentrations and low pH, were noted at the Baltic Sea stations, where the calcareous tests of the dominant living taxa Ammonia spp. and Elphidium spp. were partially to completely dissolved, probably due to a combination of different stressors affecting the required energy for biomineralization. Even though Foraminifera are able to live in extremely varying environmental conditions, the present results suggest that the benthic coastal ecosystems in the studied region, which are apparently affected by an increase in the range of environmental variability, will probably be even more influenced by a future increase in anthropogenic impacts, including coastal ocean acidification and deoxygenation.
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| 5. |
- Chierici, Melissa, 1968, et al.
(author)
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Algorithms to estimate carbon dioxide in the upper subarctic North Atlantic using observations, satellite and ocean analysis data
- 2009
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In: Deep-sea research. Part II, Topical studies in oceanography. - : Elsevier BV. - 0967-0645. ; 56, s. 630-639
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Journal article (peer-reviewed)abstract
- Observations of the surface-water fugacity of carbon dioxide (fCO2sw) measured during 2005 in the subpolar North Atlantic Ocean (58–62°N, 10–40°W) were used together with in situ ocean data and remotely sensed data to develop algorithms to estimate fCO2sw. Based on multiple regression we found that sea-surface temperature (SST), mixed-layer depth (MLD), and chlorophyll a (chl a) contributed significantly to the fit. Two algorithms were developed for periods depending on the presence of chl a data. The correlation coefficient (r2) and the root-mean-square deviation (rms) for the best fit in the period when chl a was observed (20 March–15 October) were 0.720 and ±10.8 μatm, respectively. The best fit for the algorithm for the period when no chl a was present (16 October–19 March) resulted in a r2 of 0.774 and a rms of ±5.6 μatm. Based on these algorithms we estimated seasonal fields of fCO2sw and the air–sea CO2 flux. The estimated net annual CO2 sink was 0.0058 Gt C yr−1 or 0.6 mol C m−2 yr−1.
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| 6. |
- Chierici, Melissa, 1968, et al.
(author)
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Biogeochemical evolution of the carbon dioxide system in the waters of long-lived mesoscale eddies in the Northeast Pacific Ocean
- 2005
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In: Deep-Sea Research Part Ii-Topical Studies in Oceanography. - : Elsevier BV. - 0967-0645. ; 52:7-8, s. 955-974
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Journal article (peer-reviewed)abstract
- An anticyclonic eddy, named Haida-2000, formed off the Southern Queen Charlotte Islands early in the year 2000. The eddy subsequently tracked northwest, transporting fresh, warm, and nutrient-rich water into the Northeast Pacific Ocean. Based on total dissolved inorganic carbon (CA total alkalinity (AT), and nutrients from six seasonal cruises between February 2000 and September 2001, we found that the oceanic carbonate system of the Surface waters in the eddy changed significantly. The greatest loss of C-T from the surface waters of Haida-2000 occurred during the first year, between February and June 2000. Based oil a concomitant loss in nitrate (NO3), the large CT loss we observed was likely due to biological production of organic carbon and probably resulted in a large drawdown of atmospheric CO,, as supported by the observed fugacity of carbon dioxide (fCO(2)) in the surface waters. During fall, C-T, fCO(2), and NO3 values increased, probably due to oxidation of organic matter and vertical entrainment Of CT and nutrient-rich water from below with fall mixing. As a result, the surface waters of the eddy were highly oversaturated in CO2 relative to the atmosphere. Another Haida eddy (Haida-2001) had a significantly smaller nitrate drawdown than Haida-2000 during its first spring, but the CT losses were similar in the two eddies. In early summer (mid-June) of the second year, the surface and sub-surface waters in Haida-2000 gained C-T, A(T), and NO3, partly caused by a merging with another 2001 Haida eddy, showing that exchange with surrounding waters took place and was significant at times. The high nitrate/ low chlorophyll (HNLC) surface waters at Ocean Station Papa (OSP), showed less fCO(2) Undersaturation during summer and less total nitrate and CT loss than Haida-2000, indicating that both eddies were larger sinks for carbon lthan HNLC waters. The waters surrounding the eddies generally had concentrations of C-T, A(T), and NO3 that were similar to or slightly higher than the waters of both Haida eddies throughout the study. Also, the sub-surface waters in these eddies showed no significant change in total carbon content, suggesting that at these depths eddies are recycling, not exporting systems. (c) 2005 Elsevier Ltd. All rights reserved.
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| 7. |
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| 8. |
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| 9. |
- Chierici, Melissa, 1968, et al.
(author)
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Calcium carbonate saturation in the surface water of the Arctic Ocean: undersaturation in freshwater influenced shelves
- 2009
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In: Biogeosciences. ; 6, s. 2421-2432
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Journal article (peer-reviewed)abstract
- In the summer of 2005, we sampled surface water and measured pH and total alkalinity (AT) underway aboard IB Oden along the Northwest Passage from Cape Farewell (South Greenland) to the Chukchi Sea. We investigated the variability of carbonate system parameters, focusing particularly on carbonate concentration [CO32-] and calcium carbonate saturation states, as related to freshwater addition, biological processes and physical upwelling. Measurements on AT, pH at 15 ºC, salinity (S) and sea surface temperature (SST), were used to calculate total dissolved inorganic carbon (CT), [CO32-] and the saturation of aragonite (ΩAr) and calcite (ΩCa) in the surface water. The same parameters were measured in the water column of the Bering Strait. Some surface waters in the Canadian Arctic Archipelago (CAA) and on the Mackenzie shelf (MS) were found to be undersaturated with respect to aragonite (ΩAr < 1). In these areas, surface water was low in AT and CT (< 1500 µmol kg-1) relative to seawater and showed low [CO32-]. The low saturation states were probably due to the likely the effect of dilution due to freshwater addition by sea ice melt (CAA) and river runoff (MS). High AT and CT and low pH, corresponded with the lowest [CO32-], ΩAr and ΩCa, observed near Cape Bathurst and along the South Chukchi Peninsula. This was linked to the physical upwelling of subsurface water with elevated CO2. The highest surface ΩAr and ΩCa of 3.0 and 4.5, respectively, were found on the Chukchi Sea shelf and in the cold water north of Wrangel Island, which is heavily influenced by high CO2 drawdown and lower CT from intense biological production. In the western Bering Strait, the cold and saline Anadyr Current carries water that is enriched in AT and CT from enhanced organic matter remineralization, resulting in the lowest ΩAr (~1.2) of the area.
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| 10. |
- Chierici, Melissa, 1968
(author)
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Carbon dioxide in the Arctic Ocean
- 2009
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In: Japan Swedish Scientific Association workshop, Japan.
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Conference paper (other academic/artistic)abstract
- Large areas of the Arctic shelves are largely unknown with regard to the carbon dioxide system and the processes affecting the air/sea CO2 flux. This is mainly due to sparse information and lack of data as a result of large logistical challenges to conduct measurement programs which are related to the ice cover and harsh conditions in the polar oceans. Lack of information is of great concern since predictions and observations show that the polar areas are the most vulnerable region for a climate change such as a warming. Moreover, the Arctic Ocean is also predicted to be the first to become affected by an increase in ocean CO2 such as ocean acidification. However, there are large uncertainties about the direction and magnitude of the feedback processes involved in the marine system and as well as its coupling with atmospheric forcing. Large efforts in measurement programs have to be performed to be able to gain insight and understanding of the processes governing the CO2 system. One major measuring effort was performed during summer 2005 where the first continuous surface water measurements of fugacity of CO2 (fCO2sw), was performed onboard the IB Oden along the Northwest Passage from Cape Farwell (S. Greenland) to the Chukchi Sea. CO2 system parameters were measured with the aim to investigate the importance of sea ice and river runoff on the spatial variability of fCO2 and the saturation state of calcium carbonate (Ω). The variability in these parameters are related to natural occurring features such as freshwater content, sea ice, biological processes and physical upwelling. This study highlights the value of using high-frequency measurements to gain increased insight into the variable and complex conditions, encountered on the shelves in the Arctic Ocean.
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