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Author Granskog, M.A.; Kaartokallio, H.; Thomas, D.N.; Kuosa, H. url  openurl
  Title Influence of freshwater inflow on the inorganic nutrient and dissolved organic matter within coastal sea ice and underlying waters in the Gulf of Finland (Baltic Sea) Type Journal Article
  Year 2005 Publication Estuarine, Coastal and Shelf Science Abbreviated Journal Estuar Coast Shelf Sci  
  Volume 65 Issue 1-2 Pages 109-122  
  Keywords coastal oceanography; sea ice; river plumes; estuarine chemistry; nutrients (mineral); dissolved organic matter; Baltic Sea  
  Abstract A study was conducted to measure the biogeochemical characteristics of freshwater plumes underlying Baltic Sea land-fast ice, and the overlying sea ice. A 40-km long transect was conducted in the northern Baltic Sea in March 2003, following a freshwater plume from its source into the fully mixed open-sea area. The spreading of river outflow below the ice resulted in a well-stratified low-salinity surface layer further out than normally occurs in the open-water period. The freshwaters were high in dissolved organic matter (DOC, DON and CDOM), and inorganic nutrients (ammonium, nitrate and silicate), although the levels of phosphate were low. In general these parameters changed concurrently with salinity in such a way that mixing was conservative. The characteristics of the ice varied from the freshwater source to the open water, with increasing salinity and brine volumes (porosity) occurring in the more open-sea stations. Coinciding with the changes in ice properties there was an increase in sea-ice algal growth in the more marine stations along the transect. Biological activity in the ice was largely confined to bottom ice assemblages. In contrast to the conditions in the underlying water, no relationship between salinity, inorganic nutrients and organic matter was observed in the ice. In particular ammonium, phosphate, DOC and DON were present in excess of those levels predicted from the dilution curves, indicating the presence of considerable DOM production by ice assemblages, inorganic nutrient uptake and remineralization within the ice.  
  Address  
  Corporate Author Thesis  
  Publisher Academic Press Place of Publication San Diego Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0272-7714 ISBN Medium  
  Area Expedition Conference  
  Notes Sampling: Nine stations along a 40km salinity gradient from inner Pojo Bay through the Archipelago to the edge of the open sea Approved no  
  Call Number (up) refbase @ admin @ Granskog++2005_2 Serial 740  
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Author Granskog, M.; Kaartokallio, H.; Kuosa, H.; Thomas, D.N.; Vainio, J. url  doi
openurl 
  Title Sea ice in the Baltic Sea – A review Type Journal Article
  Year 2006 Publication Estuarine, Coastal and Shelf Science Abbreviated Journal Estuar Coast Shelf Sci  
  Volume 70 Issue 1-2 Pages 145-160  
  Keywords sea ice; Baltic Sea; biogeochemistry; plankton; seasons  
  Abstract Although the seasonal ice cover of the Baltic Sea has many similarities to its oceanic counterpart in Polar Seas and Oceans, there are many unique characteristics that mainly result from the brackish waters from which the ice is formed, resulting in low bulk salinities and porosities. In addition, due to the milder climate than Polar regions, the annual maximum ice extent is highly variable, and rain and freeze-melt cycles can occur throughout winter. Up to 35% of the sea ice mass can be composed from metamorphic snow, rather than frozen seawater, and in places snow and superimposed ice can make up to 50% of the total ice thickness. There is pronounced atmospheric deposition of inorganic nutrients and heavy metals onto the ice, and in the Bothnian Bay it is estimated that 5% of the total annual flux of nitrogen and phosphorus and 20–40% of lead and cadmium may be deposited onto the ice fields from the atmosphere. It is yet unclear whether or not the ice is simply a passive store for atmospherically deposited compounds, or if they are transformed through photochemical processes or biological accumulation before released at ice and snow melt.As in Polar sea ice, the Baltic ice can harbour rich biological assemblages, both within the ice itself, and on the peripheries of the ice at the ice/water interface. Much progress has been made in recent years to study the composition of these assemblages as well as measuring biogeochemical processes within the ice related to those in underlying waters. The high dissolved organic matter loading of Baltic waters and ice result in the ice having quite different chemical characteristics than those known from Polar Oceans. The high dissolved organic material load is also responsible in large degree to shape the optical properties of Baltic Sea ice, with high absorption of solar radiation at shorter wavelengths, a prerequisite for active photochemistry of dissolved organic matter.Land-fast ice in the Baltic also greatly alters the mixing characteristics of river waters flowing into coastal waters. River plumes extend under the ice to a much greater distance, and with greater stability than in ice-free conditions. Under-ice plumes not only alter the mixing properties of the waters, but also result in changed ice growth dynamics, and ice biological assemblages, with the underside of the ice being encased, in the extreme case, with a frozen freshwater layer.There is a pronounced gradient in ice types from more saline ice in the south to freshwater ice in the north. The former is characteristically more porous and supports more ice-associated biology than the latter. Ice conditions also vary considerably in different parts of the Baltic Sea, with ice persisting for over half a year in the northernmost part of the Baltic Sea, the Bothnian Bay. In the southern Baltic Sea, ice appears only during severe winters.  
  Address Granskog: Arctic Centre, University of Lapland, P.O. Box 122, FI-96101 Rovaniemi, Finland  
  Corporate Author Thesis  
  Publisher Elsevier Science BV Place of Publication Amsterdam Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0272-7714 ISBN Medium  
  Area Baltic Sea Expedition Conference  
  Notes Review Approved no  
  Call Number (up) refbase @ admin @ Granskog++2006 Serial 738  
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Author Haas, C.; Thomas, D.N.; Bareiss, J. url  openurl
  Title Surface properties and processes of perennial Antarctic sea ice in summer Type Journal Article
  Year 2001 Publication Journal of Glaciology Abbreviated Journal J Glaciol  
  Volume 47 Issue 159 Pages 613-625  
  Keywords  
  Abstract Ice-core and snow data from the Amundsen, Bellingshausen and Weddell Seas, Antarctica, show that the formation of superimposed ice and the development of seawater-filled gap layers with high algal standing stocks is typical of the perennial sea ice in summer. The coarse-grained and dense snow had salinities mostly below 0.1ppt. A layer of fresh superimposed ice had a mean thickness of 0.04-0.12 m. Gap layers 0.04-0.08 m thick extended downwards from 0.02 to 0.14 m below the water level. These gaps were populated by diatom standing stocks up to 439 ?g L?¹ chlorophyll a. We propose a comprehensive heuristic model of summer processes, where warming and the reversal of temperature gradients cause major transformations in snow and ice properties. The warming also causes the reopening of incompletely frozen slush layers caused by flood-freeze cycles during winter. Alternatively, superimposed ice forms at the cold interface between snow and slush in the case of flooding with negative freeboard. Combined, these explain the initial formation of gap layers by abiotic means alone. The upward growth of superimposed ice above the water level competes with a steady submergence of floes due to bottom and internal melting and accumulation of snow.  
  Address  
  Corporate Author Thesis  
  Publisher International Glaciological Society Place of Publication Cambridge Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0022-1430 ISBN Medium  
  Area Expedition Conference  
  Notes IPØ/Tvärrminne Approved no  
  Call Number (up) refbase @ admin @ Haas++2001 Serial 742  
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Author Herborg, L.-M.; Thomas, D.N.; Kennedy, H.; Haas, C.; Dieckmann, G.S. url  openurl
  Title Dissolved carbohydrates in Antarctic sea ice Type Journal Article
  Year 2001 Publication Antarctic Science Abbreviated Journal Antarct Sci  
  Volume 13 Issue 2 Pages 119-125  
  Keywords Doc; Mcho; Pcho; sea ice; bacteria; carbon cycling; diatoms; dissolved organic carbon; monocarbohydrates; polycarbohydrates  
  Abstract Concentrations of dissolved monocarbohydrates (MCHO) and polycarbohydrates (PCHO) were analysed in a variety of ice habitats from summer Weddell Sea sea ice (surface ponds, ice cores, gap layers and platelet ice). The dissolved organic carbon (DOC) pool in these habitats was also measured and the contribution of carbohydrate to this pool was assessed. The DOC concentrations within all sea ice habitats were high compared to surface seawater concentrations with values up to 958µMC being measured. Total carbohydrates (TCHO) were highest in the ice cores and platelet ice samples, up to 3 1% of the DOC pool, a reflection of the high algal biomass in these two habitat classes. TCHO in the other habitats ranged between 10% and 29% of DOC. The ratios of MCHO to PCHO varied considerably between the ice habitats: in surface ponds and ice cores MCHO was 70% of the TCHO pool, whereas in gap layers and platelet ice there were lower PCHO concentrations resulting in MCHO being 88% of TCHO.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number (up) refbase @ admin @ Herborg++2001 Serial 743  
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Author Kaartokallio, H.; Kuosa, H.; Thomas, D.N.; Granskog, M.A.; Kivi, K. url  openurl
  Title Biomass, composition and activity of organism assemblages along a salinity gradient in sea ice subjected to river discharge in the Baltic Sea Type Journal Article
  Year 2006 Publication Polar Biology Abbreviated Journal Polar Biol  
  Volume 30 Issue 2 Pages 183-197  
  Keywords  
  Abstract A study was undertaken to examine the activity and composition of the seasonal Baltic Sea land-fast sea-ice biota along a salinity gradient in March 2003 in a coastal location in the SW coast of Finland. Using a multi-variable data set, the less well-known algal and protozoan communities, and algal and bacterial production in relation to the physical and chemical environment were investigated. Also, the first coincident measurements of bacterial production and dissolved organic matter (DOM) in a sea-ice system are reported. Communities in sea ice were clearly autotrophy-dominated with algal biomass representing 79% of the total biomass. Protozoa and rotifers made up 18% of biomass in the ice and bacteria only 3%. Highest biomasses were found in mid-transect bottom ice. Water column assemblages were clearly more heterotrophic: 39% algae, 12% bacteria and 49% for rotifers and protozoa. Few significant correlations existed between DOM and bacterial variables, reflecting the complex origin of ice DOM. Dynamics of dissolved organic carbon, nitrogen and phosphorus (DOC, DON and DOP) were also uncoupled. A functional microbial loop is likely to be present in the studied ice. Existence of an under-ice freshwater plume affects the ecosystem functioning: Under-ice water communities are influenced directly by river-water mixing, whereas the ice system seems to be more independent–the interaction mainly taking place through the formation of active bottom communities.  
  Address  
  Corporate Author Thesis  
  Publisher Springer-Verlag Place of Publication Heidelberg Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0722-4060 ISBN Medium  
  Area Expedition Conference  
  Notes Sampling: Nine stations along a 40km salinity gradient from inner Pojo Bay through the Archipelago to the edge of the open sea Approved no  
  Call Number (up) refbase @ admin @ Kaartokallio++2006 Serial 744  
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