Relevant bibliographies by topics / Bothnian Sea

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  2. Dissertations / Theses
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  5. Conference papers

Academic literature on the topic 'Bothnian Sea'

Author: Grafiati
Published: 4 June 2021
Last updated: 1 February 2022

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Journal articles on the topic "Bothnian Sea"

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Neumann, Thomas, Herbert Siegel, Matthias Moros, Monika Gerth, Madline Kniebusch, and Daniel Heydebreck. "Ventilation of the northern Baltic Sea." Ocean Science 16, no. 4 (July 3, 2020): 767–80. http://dx.doi.org/10.5194/os-16-767-2020.

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Abstract. The Baltic Sea is a semi-enclosed, brackish water sea in northern Europe. The deep basins of the central Baltic Sea regularly show hypoxic conditions. In contrast, the northern parts of the Baltic Sea, the Bothnian Sea and Bothnian Bay, are well oxygenated. Lateral inflows or a ventilation due to convection are possible mechanisms for high oxygen concentrations in the deep water of the northern Baltic Sea. In March 2017, conductivity–temperature–depth (CTD) profiles and bottle samples, ice core samples, and brine were collected in the Bothnian Bay. In addition to hydrographic standard parameters, light absorption has been measured in all samples. A complementary numerical model simulation provides quantitative estimates of the spread of newly formed bottom water. The model uses passive and age tracers to identify and trace different water masses. Observations indicate a recent ventilation of the deep bottom water at one of the observed stations. The analysis of observations and model simulations shows that the Bothnian Bay is ventilated by dense water formed due to mixing of Bothnian Sea and Bothnian Bay surface water initializing lateral inflows. The observations show the beginning of the inflow and the model simulation demonstrates the further northward spreading of bottom water. These events occur during wintertime when the water temperature is low. Brine rejected during ice formation barely contributes to dense bottom water.
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Mäntyniemi, Samu, Atso Romakkaniemi, Johan Dannewitz, Stefan Palm, Tapani Pakarinen, Henni Pulkkinen, Anna Gårdmark, and Olle Karlsson. "Both predation and feeding opportunities may explain changes in survival of Baltic salmon post-smolts." ICES Journal of Marine Science 69, no. 9 (May 15, 2012): 1574–79. http://dx.doi.org/10.1093/icesjms/fss088.

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Abstract Mäntyniemi, S., Romakkaniemi, A., Dannewitz, J., Palm, S., Pakarinen, T., Pulkkinen, H., Gårdmark, A., and Karlsson, O. 2012. Both predation and feeding opportunities may explain changes in survival of Baltic salmon post-smolts. – ICES Journal of Marine Science, 69: 1574–1579. The survival of wild and hatchery-reared post-smolts of salmon (Salmo salar) in the Baltic Sea has declined since the 1990s. Direct observations of the processes affecting survival are, however, lacking. Here, the importance of food availability and predation in regulating post-smolt survival is analysed. Based on previous studies, the following explanatory variables were selected: (i) availability of herring (Clupea harengus membras) recruits in the Gulf of Bothnia (Bothnian Sea, Bothnian Bay) in the northern Baltic Sea; (ii) sprat (Sprattus sprattus balticus) and herring abundance in the southern Baltic Sea; and (iii) abundance of grey seal (Halichoerus grypus) along the post-smolt migration route. Bayesian analysis was used to estimate the relative probability of each of the 32 combinations of these variables and revealed that the model including grey seal abundance and herring recruits per post-smolt had the highest posterior probability and a high coefficient of determination. The results suggest that the declining trend in post-smolt survival is explained by the increased number of grey seals, whereas the annual variation in survival coincides with variation in the recruitment of Bothnian Sea herring. However, it remains uncertain whether the observed correlations arise from direct causalities or other mechanisms.
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Kallio-Nyberg, Irma, Heikki Peltonen, and Hannu Rita. "Effects of stock-specific and environmental factors on the feeding migration of Atlantic salmon (Salmo salar) in the Baltic Sea." Canadian Journal of Fisheries and Aquatic Sciences 56, no. 5 (May 1, 1999): 853–61. http://dx.doi.org/10.1139/f99-022.

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Atlantic salmon (Salmo salar L.) stocks in the Baltic Sea are mainly exploited during their sea migration. The offshore fishery in the feeding grounds of these salmon permitted us to analyse the migrations of certain stocks on the basis of tag recovery data. Four salmon stocks from rivers draining into Bothnian Bay (25°E, 65.5°N) were selected for study. During 1984-1991, about 135 000 2-year-old hatchery-reared smolts were tagged and released. We applied logit models, with the site of recovery as a multicategory response variable, to analyse the distribution of tag recoveries in the Baltic Sea feeding grounds. The results showed the combined influence of stock, prey abundance, and smolt size on the spatial marine distribution of the salmon. Although stock-specific sea migration patterns were apparent, annual environmental factors had a stronger influence on the sea migration route of salmon than did the stock factor. The salmon released as small smolts (total length [Formula: see text] 17.0 cm) were more frequently caught farther from the release site than were those released as larger smolts (>17 cm). The abundance of suitable prey (age 0+ herring) in the year of smolt release was found to be a key factor influencing the migration distance. The salmon released in the years of strong herring recruitment in the Gulf of Bothnia had a higher probability to stay in the Bothnian Sea for feeding and not to migrate farther south.
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Rajasilta, M., J. Hänninen, and I. Vuorinen. "Decreasing salinity improves the feeding conditions of the Baltic herring (Clupea harengus membras) during spring in the Bothnian Sea, northern Baltic." ICES Journal of Marine Science 71, no. 5 (April 2, 2014): 1148–52. http://dx.doi.org/10.1093/icesjms/fsu047.

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Abstract The stomach contents of the herring (Clupea harengus membras L.) from the Bothnian Sea, northern Baltic, were analysed during spring 2011 and 2013. The stomachs were full of Limnocalanus macrurus in May and June, and an improvement in the condition of herring was observed when fish started to feed on this prey. The analyses showed that Limnocalanus is currently an important link between lower trophic levels and Baltic herring in the Bothnian Sea.
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Gelting, J., E. Breitbarth, B. Stolpe, M. Hassellöv, and J. Ingri. "Fractionation of iron species and iron isotopes in the Baltic Sea euphotic zone." Biogeosciences Discussions 6, no. 4 (July 2, 2009): 6491–537. http://dx.doi.org/10.5194/bgd-6-6491-2009.

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Abstract. Measurements of the physiochemical speciation of Fe in the euphotic zone were performed at three different locations, over a well defined salinity gradient, during spring and summer in the Baltic Sea. The average of total Fe changed from 114 nM in the Bothnian Sea, 44 nM at Landsort Deep and 15 nM at Gotland Deep. Particulate Fe (PFe) was the dominating phase at all stations and on average accounted for 75–85% of the total Fe pool. At all three locations, a decrease in total Fe of 80–90% from initial measurements compared to the summer was found. A strong positive correlation between PFe and chl-a was observed. Hence, primary production strongly regulates cycling of suspended Fe. However, this relation is not dominated by active uptake of Fe in phytoplankton; instead this reflects cycling of phosphorus, growth of diatoms, and removal of PFe during phytoplankton sedimentation. The average colloidal iron fraction, CFe, showed decreasing concentrations along the salinity gradient; Bothnian Sea 15 nM; Landsort Deep 1 nM and Gotland Deep 0.5 nM. Field Flow Fractionation data indicate that the main colloidal carrier phase for Fe in the Baltic Sea is a carbon-rich fulvic acid associated compound, likely of riverine origin. The Fe isotope composition (δ56Fe) of the PFe showed constant positive values in the Bothnian Sea surface waters (+0.08 to +0.20‰). Enrichment of heavy Fe in the Bothnian Sea PFe is most likely associated to input of aggregated land derived Fe-oxyhydroxides and a rapid overturn of Fe(II). At the Landsort deep, the fractionation of PFe changed between −0.08‰ to +0.28‰. The negative values, in early spring, probably indicate exchange over the oxic-anoxic boundary at ~80 m depth.
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Gelting, J., E. Breitbarth, B. Stolpe, M. Hassellöv, and J. Ingri. "Fractionation of iron species and iron isotopes in the Baltic Sea euphotic zone." Biogeosciences 7, no. 8 (August 23, 2010): 2489–508. http://dx.doi.org/10.5194/bg-7-2489-2010.

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Abstract. To indentify sources and transport mechanisms of iron in a coastal marine environment, we conducted measurements of the physiochemical speciation of Fe in the euphotic zone at three different locations in the Baltic Sea. In addition to sampling across a salinity gradient, we conducted this study over the spring and summer season. Moving from the riverine input characterized low salinity Bothnian Sea, via the Landsort Deep near Stockholm, towards the Gotland Deep in the Baltic Proper, total Fe concentrations averaged 114, 44, and 15 nM, respectively. At all three locations, a decrease in total Fe of 80–90% from early spring to summer was observed. Particulate Fe (PFe) was the dominating phase at all stations and accounted for 75–85% of the total Fe pool on average. The Fe isotope composition (δ 56Fe) of the PFe showed constant positive values in the Bothnian Sea surface waters (+0.08 to +0.20‰). Enrichment of heavy Fe in the Bothnian Sea PFe is possibly associated to input of aggregated land derived Fe-oxyhydroxides and oxidation of dissolved Fe(II). At the Landsort Deep the isotopic fractionation of PFe changed between −0.08‰ to +0.28‰ over the sampling period. The negative values in early spring indicate transport of PFe from the oxic-anoxic boundary at ∼80 m depth. The average colloidal iron fraction (CFe) showed decreasing concentrations along the salinity gradient; Bothnian Sea 15 nM; Landsort Deep 1 nM, and Gotland Deep 0.5 nM. Field Flow Fractionation data indicate that the main colloidal carrier phase for Fe in the Baltic Sea is a carbon-rich fulvic acid associated compound, likely of riverine origin. A strong positive correlation between PFe and chl-a indicates that cycling of suspended Fe is at least partially controlled by primary production. However, this relationship may not be dominated by active uptake of Fe into phytoplankton, but instead may reflect scavenging and removal of PFe during phytoplankton sedimentation.
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Busse, Svenja, and Pauli Snoeijs. "Gradient responses of diatom communities in the Bothnian Bay, northern Baltic Sea." Nova Hedwigia 74, no. 3-4 (May 1, 2002): 501–25. http://dx.doi.org/10.1127/0029-5035/2002/0074-0501.

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Peltonen, Heikki, and Helge Balk. "The acoustic target strength of herring (Clupea harengus L.) in the northern Baltic Sea." ICES Journal of Marine Science 62, no. 4 (January 1, 2005): 803–8. http://dx.doi.org/10.1016/j.icesjms.2005.02.001.

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Abstract The hydro-acoustic target strength (TS) of herring (Clupea harengus L.) was estimated from the catch composition of 19 pelagic-trawl hauls and from simultaneous recordings with a split-beam, 38 kHz echosounder. The data were collected in September 2000 during a Bothnian Sea survey in the northern Baltic Sea. The dependence of TS (in dB) on fish length (L, cm) was modelled with the equation TS = a log10 L + b. The fitted model was TS = 16.8 log10 L − 60.0. With a predefined slope of 20 the TS vs. log-fish length relationship was TS = 20 log10 L − 63.9. The analyses suggested that TS was higher in the Bothnian Sea than is assumed in most studies in the Baltic Sea. Applying the revised TS–length dependence considerably enhanced the agreement between the biomass estimates from hydroacoustics and those from a catche-at-age analysis (VPA).
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Hyttinen, O., A. T. Kotilainen, J. J. Virtasalo, P. Kekäläinen, I. Snowball, S. Obrochta, and T. Andrén. "Holocene stratigraphy of the Ångermanälven River estuary, Bothnian Sea." Geo-Marine Letters 37, no. 3 (December 5, 2016): 273–88. http://dx.doi.org/10.1007/s00367-016-0490-2.

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Yi, P., A. Aldahan, G. Possnert, X. L. Hou, P. He, and B. Wang. "Depth profiles of 129I species in the Bothnian Sea." Journal of Radioanalytical and Nuclear Chemistry 295, no. 2 (July 17, 2012): 1459–63. http://dx.doi.org/10.1007/s10967-012-1923-7.

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Dissertations / Theses on the topic "Bothnian Sea"

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Linder, Wiktorsson Emilia. "Eutrophication effects on a coastal macrophyte community in the Bothnian Sea." Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-184367.

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Eutrophication is a major concern in the Baltic Sea and it is affecting macrophyte communities by promoting the growth of opportunistic algae and decreasing the cover of perennial macrophyte species via shading. It is however uncertain how common eutrophication and its symptoms are in the northern parts of the Baltic Sea, the Botnian Sea. The aim of this study was to evaluate if Sörleviken, a bay in the Bothnian Sea, show signs of increased eutrophication pressure in 2020 compared to 2007 based on changes in macrophyte cover and composition. The macrophyte community was inventoried with under-water video techniques in 2020 along three transects, matching transects previously inventoried by a diver in 2007. The three transects were located in the inner, middle and the outer parts of the bay. The results showed that macrophyte diversity was lower in 2020 than in 2007 along the outer transect, but overall, the total cover of macrophytes, relative cover of opportunistic algae, species richness and evenness remained unchanged. A possible higher presence of Stuckenia pectinata (former Potamogeton pectinatus) and a possible lower presence of Chara aspera in 2o2o compared to 2007 might be evidence of higher eutrophication pressure in 2020. However, by observing the general changes in the macrophyte community, this study only provides weak or inconclusive signs of increased eutrophication pressure, thus Sörleviken shows no signs of either improvement of or further increases in eutrophication pressure by 2020 compared to the observations in 2007.
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Nordlöf, Ulrika. "Levels of organohalogen compounds in White-tailed sea eagles (Haliaeetus albicilla) in relation to reproduction impairment in the Bothnian Sea." Doctoral thesis, Stockholms universitet, Institutionen för tillämpad miljövetenskap (ITM), 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-74634.

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The white-tailed sea eagle (Haliaeetus albicilla) is in the top of the marine food chain and its existence in Sweden has been threatened several times. The species succeeded to recover from the deep decline in the 1970s when the exposure to persistent organic pollutants influenced the reproduction negatively. The species is today spread over the country but is still seen as a near threatened species. Even though a recovery has occurred there is still some reproduction problems seen in the region of the south Bothnian Sea. The work presented in this thesis has focused on expanding the knowledge of bromine and chlorine containing compounds in the white-tailed sea eagles and to correlate the levels found with the reproduction impairment in the region of south Bothnian Sea. Eggs and blood from nestlings collected from different subpopulations, from the Arctic (Lapland) in the north to the Baltic Proper in the south of Sweden, have been studied for polychlorinated dibenzo-p-dioxins (PCDD), dibenzofurans (PCDF), non-ortho-substituted polychlorinated biphenyl (PCB), brominated flame retardants, methoxylated- (MeO-), and hydroxylated- (OH)-polybrominated diphenyl ethers (PBDEs). Some of the investigated compounds have been compared with levels found in a unique white-tailed sea eagle egg collected in the Baltic Proper in 1941. The pattern and levels of PCDD and PCDF in 1941 were similar and in the same range as found today around the same area. Furthermore, the human activity has raised the PCB levels in the white-tailed sea eagles with over 120 times over the last 60 years but these levels are still much lower than in the 1970s. In conclusion none of the investigated compounds in this thesis could be correlated to the reduced reproduction seen in the south Bothnian Sea but the levels of PCDD, PCDF, non-ortho­-PCB and OH-PBDE are high in the populations inhabiting the Baltic Sea and are in the same range as found to cause different biological responses in other avian species worldwide.

At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: In press. Paper 3: Submitted. Paper 4: Manuscript.

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Wannäs, Kjell O. "Seismic stratigraphy and tectonic development of the Upper Proterozoic to Lower Palaozoic of the Bothnian Bay, Baltic Sea." Doctoral thesis, Stockholms universitet, Naturvetenskapliga fakulteten, 1989. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-81975.

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Carlén, Simon. "Identifying Sources and Ecological Risks of Polycyclic Aromatic Hydrocarbons in Polluted Fiber Enriched Sediments from the Bothnian Sea." Thesis, Umeå universitet, Kemiska institutionen, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-165721.

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Vonk, Jorien Elisabeth. "Molecular and isotopic characterization of terrestrial organic carbon released to (sub-)Arctic coastal waters." Doctoral thesis, Stockholm : Department of Applied Environmental Science (ITM), Stockholm University, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-38589.

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Diss. (sammanfattning) Stockholm : Stockholms universitet, 2010.
At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 3: Accepted. Paper 4: Manuscript. Härtill 4 uppsatser.
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Lindberg, Adrian. "Skeppssättning och Långröse : En komparativ studie längsmed Norrlands kustområde." Thesis, Uppsala universitet, Institutionen för arkeologi och antik historia, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-414247.

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Through social landscape theory the aim of this thesis is to broaden the understanding of the bronze age monumental graves on the coast of Norrland. Questions about similarities between the stone ship settings and long cairns are analysed by looking at size and placement in the landscape. This shows the possible connections between the two construction types and were questioned throughout the process of writing. A reconstructed shoreline set to Late Nordic Bronze Age period IV, has been analysed by looking at the monuments placement to see possible connections through a maritory between Norrland and southern Sweden. In this thesis I have incorporated some instances of Gotlandic as well as other stone ship settings and long cairns from the Baltic Sea area, to strengthen the point of a possible maritory that connected the societies of northern Sweden with the societies placed around the Baltic Sea. The long cairns can be found in Gävleborg’s county from Söderala parish along the coast all the way up to Byske parish in Västerbotten’s county and seem to be constructed in a way that follow the shape of the mountain, with some anomalies. Stone ship settings can usually be found along the mouth of rivers and are placed more specific in the environment, where the orientation seems to relate to the ancient shoreline and in some cases the monument even point towards plausible routes that would be possible to follow with a ship inland. There is a clear concentration of all monument types in Västernorrland’s county, more specifically around the area of Docksta. The placement of the monuments above sea level in relation to the ancient shoreline, seems to be varied, with no clear rule of what height they should lay on. Many similarities can be found between the two, yet so many differences that only can be answered by excavations of more monuments. Further research and excavations is needed in Norrland with focus on the Bronze Age, which is crucial for the understanding of Sweden’s northern coastal areas and the trade across the Baltic Sea.
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Gylle, A. Maria. "Physiological adaptations in two ecotypes of Fucus vesiculosus and in Fucus radicans with focus on salinity." Doctoral thesis, Mittuniversitetet, Institutionen för naturvetenskap, teknik och matematik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-13308.

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The in origin intertidal marine brown alga Fucus vesiculosus L. grow permanently sublittoral in the brackish Bothnian Sea, side by side with the recently discovered F. radicans L. Bergström et L. Kautsky. Environmental conditions like salinity, light and temperature are clearly different between F. vesiculosus growth sites in the Bothnian Sea (4-5 practical salinity units, psu; part of the Baltic Sea) and the tidal Norwegian Sea (34-35 psu; part of the Atlantic Ocean). The general aims of this thesis were to compare physiological aspects between the marine ecotype and the brackish ecotype of F. vesiculosus as well as between the two Bothnian Sea species F. vesiculosus and F. radicans. The result in the study indicates a higher number of water soluble organic compounds in the marine ecotype of F. vesiculosus compared to the brackish ecotype. These compounds are suggested to be compatible solutes and be due to an intertidal and sublittoral adaptation, respectively; where the intertidal ecotype needs the compounds as a protection from oxygen radicals produced during high irradiation at low tide. The sublittoral ecotype might have lost the ability to synthesize these compound/compounds due to its habitat adaptation. The mannitol content is also higher in the marine ecotype compared to the brackish ecotype of F. vesiculosus and this is suggested to be due to both higher level of irradiance and higher salinity at the growth site. 77 K fluorescence emission spectra and immunoblotting of D1 and PsaA proteins indicate that both ecotypes of F. vesiculosus as well as F. radicans have an uneven ratio of photosystem II/photosystem I (PSII/PSI) with an overweight of PSI. The fluorescence emission spectrum of the Bothnian Sea ecotype of F. vesiculosus however, indicates a larger light-harvesting antenna of PSII compared to the marine ecotype of F. vesiculosus and F. radicans. Distinct differences in 77 K fluorescence emission spectra between the Bothnian Sea ecotype of F. vesiculosus and F. radicans confirm that this is a reliable method to use to separate these species. The marine ecotype of F. vesiculosus has a higher photosynthetic maximum (Pmax) compared to the brackish ecotype of F. vesiculosus and F. radicans whereas both the brackish species have similar Pmax. A reason for higher Pmax in the marine ecotype of F. vesiculosus compared to F. radicans is the greater relative amount of ribulose-1.5-bisphosphate carboxylase/oxygenase (Rubisco). The reason for higher Pmax in marine ecotype of F. vesiculosus compare to the brackish ecotype however is not due to the relative amount of Rubisco and further studies of the rate of CO2 fixation by Rubisco is recommended. Treatments of the brackish ecotype of F. vesiculosus in higher salinity than the Bothnian Sea natural water indicate that the most favourable salinity for high Pmax is 10 psu, followed by 20 psu. One part of the explanation to a high Pmax in 10 psu is a greater relative amount of PsaA protein in algae treated in 10 psu. The reason for greater amount of PsaA might be that the algae need to produce more ATP, and are able to have a higher flow of cyclic electron transport around PSI to serve a higher rate of CO2 fixation by Rubisco. However, studies of the rate of CO2 fixation by Rubisco in algae treated in similar salinities as in present study are recommended to confirm this theory.
Fucus vesiculosus L. (Blåstång) är en brunalg som i huvudsak växer i tidvattenzonen i marint vatten men arten klarar också att växa konstant under ytan i det bräckta Bottenhavet. Norska havet och den del av Bottenhavet, där algerna är insamlade i denna studie, har salthalterna 34-35 psu (praktisk salthaltsenhet) respektive 4-5 psu. F. radicans L. Bergström et L. Kautsky (Smaltång) är en nyligen upptäckt art (2005) som har utvecklats i Bottenhavet. F. radicans och Bottenhavets ekotyp av F. vesiculosus växer sida vid sida och har tidigare ansetts vara samma art. Sett till hela Östersjön, så ändras ytans salthalt från 25 till 1-2 psu mellan Östersjöns gräns mot Kattegatt och norra Bottenviken. Den låga salthalten i Östersjön beror på det höga flödet av sötvatten från älvarna och på ett litet inflödet av saltvatten i inloppet vid Kattegatt. Salthaltsgradienten är korrelerad med antalet arter som minskar med minskad salthalt. Östersjön är ett artfattigt hav och de arter som finns är till stor del en blandning av söt- och saltvattenarter. Det finns bara ett fåtal arter som är helt anpassade till bräckt vatten och F. radicans är en av dem. Exempel på miljöskillnader för F. vesiculosus i Norska havet och i Bottenhavet är salthalten, tidvattnet, ljuset och temperaturen. Tidvattnet i Norska havet gör att algerna växlar mellan att vara i vattnet och på land, vilket utsätter algerna för stora ljusskillnader, snabba och stora temperaturväxlingar samt även torka. De alger som växer i Bottenhavet har däremot en jämnare och lägre temperatur, istäcke på vintern och mindre tillgång på ljus eftersom de alltid lever under vattenytan. Skillnaderna i miljön mellan växtplatserna leder till skillnader i fysiologiska anpassningar. Anledningen till att F. vesiculosus och F. radicans valdes som studieobjekt i denna avhandling är att de är viktiga nyckelarter i Bottenhavet. F. vesiculosus och F. radicans är de enda större bältesbildande alger som finns i det artfattiga ekosystemet och de används därför flitigt som mat, gömställe, parningsplats och barnkammare för t.ex. fisk. Att de är nyckelarter gör det angeläget att försöka förstå hur algerna är anpassade och hur de reagerar på miljöförändringar för att få veta hur de kan skyddas och bevaras. F. radicans inkluderades även för att se hur en naturlig art i Bottenhavet är anpassad i jämförelse med den invandrade F. vesiculosus. Marin F. vesiculosus inkluderades för att vara en artreferens från artens naturliga växtplats. Studien visar att det finns fler vattenlösliga organiska substanser (finns vissa organiska substanser som har en proteinskyddande funktion) i den marina ekotypen av of F. vesiculosus än i Bottenhavets ekotyp. Anledningen till detta föreslås vara en anpassning till att växa i tidvattenzonen. Vid lågvatten utsätts F. vesiculosus från Norska havet för starkt ljus, uttorkning, och snabba temperatur- växlingar vilket gör att den kan behöva dessa organiska substanser som skydd mot fria syreradikaler som bildas under lågvattenexponeringarna. F. vesiculosus från Bottenhavet har troligen mist förmågan att syntetisera dessa substanser på grund av anpassning till att hela tiden växa under ytan. Mängden mannitol (socker) är högre i den marina ekotypen av of F. vesiculosus än i Bottenhavets ekotyp. Detta föreslås bero på högre fotosyntetiskt maximum i F. vesiculosus från Norska havet jämfört med ekotypen från Bottenhavet. Skillnaden i fotssyntetiskt maximum är bland annat kopplat till ljus- och salthaltskillnaden på algernas växtplatser. Denna teori styrks av att både fotosyntesen och halten av mannitol ökar i Bottenhavets ekotyp när den behandlas i högre salthalt. Studien visar även att båda ekotyperna av F. vesiculosus samt F. radicans har ett ojämnt förhållande mellan fotosystem II och I (PSII och PSI) med en dominans av PSI. Denna slutsats är baserad på fluorescens emissions mätningar vid 77 K (-196 °C) och mätning av den relativa mängden D1 protein (motsvarar PSII) och PsaA protein (motsvarar PSI). F. vesiculosus från Bottenhavet visar ett emission spektrum som pekar mot en jämnare fördelning av PSII och PSI jämfört med den marina ekotypen och F. radicans. Detta stämmer dock inte med förhållandet mellan D1/PsaA som indikerar att alla tre har mer PSI än PSII. Förklaringen till avvikelsen mellan metoderna antas vara att F. vesiculosus från Bottenhavet har större ljus-infångande antennpigment än marin F. vesiculosus och F. radicans. De tydliga skillnaderna i 77 K fluorescens emission spektra mellan Bottenhavets F. vesiculosus och F. radicans visar att denna metod kan användas som säker artidentifiering. Den marina ekotypen av F. vesiculosus har högre fotosyntetiskt maximum än de båda arterna från Bottenhavet. Mätningar av den relativa mängden av enzymet Rubisco, viktigt för upptaget av koldioxid hos växter och alger, visar att mängden enzym är en sannolik förklaring till skillnaden i fotosyntetiskt maximum mellan den marina ekotypen av F. vesiculosus och F. radicans och detta är troligen en normal artskillnad. Mängden Rubisco kan dock inte förklara skillnaden i fotosyntetiskt maximum mellan de båda ekotyperna av F. vesiculosus. För att undersöka vad skillnaden mellan dessa två beror på så föreslås istället mätningar av Rubisco’s koldioxidfixeringshastighet. Det är en ökning av fotosyntetiskt maximum i Bottenhavets ekotyp av F. vesiculosus när den behandlas i högre salthalt (10, 20 och 35 psu) och det högsta fotosyntetiska maximumet uppmättes i alger som behandlats i 10 psu. Denna ökning beror inte på ökning i den relativa mängden av Rubisco. Ökningen i fotosyntesen speglas dock av en ökning av den relativa mängden PsaA. Detta antas bero på att det behövs mer energi i form av ATP och att en ökning av detta kan ske på grund av att mer PsaA kan driva den cykliska elektrontransporten i fotosyntesreaktionen. Ökat behov av ATP antas bero på en ökning av Rubisco aktiviteten men mätning av aktiviteten krävs för att bekräfta detta.
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8

Matthews, P. A. "Crustal structure of the Baltic shield beneath the Sea of Bothnia; BABEL line 6." Thesis, Durham University, 1993. http://etheses.dur.ac.uk/5720/.

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As part of the 1989 BABEL project, Durham University recorded large quantities of high resolution wide-angle data from six deep seismic lines shot in the Gulf of Bothnia. Fifteen analogue and three digital seismic recording stations were used, located in Sweden around the Sea of Bothnia. The wide-angle data is of very high quality due to the low noise and good transmission of seismic energy through the cratonic crust of the Baltic Shield. BABEL line 6 is a 240 km long, north-south profile in the western half of the Sea of Bothnia that runs almost parallel to several deep seismic refraction profiles previously acquired in Sweden and Finland. A crustal model has been developed for this line from P- and S-wave wide-angle data recorded at five of the online recording stations and from the normal-incidence data. This model has been generated by raytracing methods using a modified version of the BEAMS? gaussian beam package. Wide-angle arrivals are interpreted as diving rays and wide-angle reflections and as 'diffraction-type' arrivals from offsets on reflecting boundaries. The wide-angle reflections appear to correspond to the boundaries between high and low reflectivity zones in the normal-incidence data. The 'diffraction-type' arrivals appear to be related to surface features such as the Ljusnan tectonic zone and the Aranda rift. There is no evidence for a Moho trench similar to those seen on neighbouring profiles. Several high velocity layers are required in the model. These may be the related to the numerous post-orogenic intrusions that have occurred in the Svecofennian region of the Baltic Shield. Traditional approaches to modelling wide-angle data assume that the crust consists of a series of extensive, quasi-horizontal, layers. There are several problems with this approach. In particular it does not explain the patchy reflectivity seen in the normal-incidence data or the rapid variation in amplitude seen along wide-angle arrivals in high resolution data sets. Apparently continuous wide-angle arrivals may be generated from a series of short length reflectors. These show an amplitude variation similar to that seen in the experimental data. This suggests that wide-angle arrivals may arise from the assemblages of reflectors that are often imaged on normal-incidence data.
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9

Jiménez, Aguilera Helia Isabel. "Spatial variation of cyanobacteria in the Gulf of Bothnia." Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-171698.

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As cyanobacteria can be found in a wide variety of environments and can cause great damage to ecosystems, human health, and economy, it is important to monitor and understand their behaviour. In this case, the study aims to understand the spatial variations of cyanobacteria communities in the Gulf of Bothnia, by analysing environmental factors that affect them. I hypothesize that the variations from north to south and coast to offshore of nutrients such as phosphorus and nitrogen promote the occurrence of different cyanobacteria orders, i.e. Chroococcales, Oscillatoriales, and Nostocales. The methods used were 16S amplicon DNA sequencing and the traditional microscopy method. Both showed similar results: Nostocales seem to predominate south-offshore zones and Oscillatoriales coast-north stations. Nevertheless, contrary to what was hypothesized on the beginning, Chroococcales were widely distributed between the stations. Both analysis methods used have limitations and strengths, thus, they should complement each other. Moreover, the DNA method must be implemented in cyanobacterial monitoring for the Baltic Sea. On the other hand, it can be said that environmental variables such as nutrients, jointly with other parameters, such as salinity, pH, humic substances and DOC (dissolved organic carbon), influence cyanobacteria communities’ composition. Overall, the environmental factors in the Baltic Sea give cyanobacteria the perfect conditions for living and develop. Therefore, it is important to implement water management and monitoring plans, as temperatures are predicted to rise globally with climate change, thus, cyanobacterial blooms are also predicted to be more common.
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10

Graham, Daniel P. "A seismic study of the mid- and lower-crust beneath the sea of Bothnia : BABEL line 1." Thesis, Durham University, 1994. http://etheses.dur.ac.uk/5601/.

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In the Autumn of 1989, Durham University took part in the BABEL Project, a collaboration of scientists from five nations recording wide angle and normal incidence seismic data in the Baltic Shield. Recording stations were set up along the Swedish coast of the Sea of Bothnia to record marine airgun shots at wide angle. Similar stations were operated by Finnish teams on the eastern coast, and by a German team on Aland. The data recorded are of high quality and high resolution in comparison to previous wide angle surveys in the region, with a shot spacing of 75 m. A large proportion (around fifty percent) of the project involved developing software for processing this data. The in-line data from Line 1, and also those recorded at two off-line stations, have been interpreted using Cerveny's Gaussian Beam forward modelling package BEAM87, the in-line model being further constrained by 2D gravity modelling. The resulting models are compared and contrasted with normal incidence data from the same line, other models derived from BABEL data in the Sea of Bothnia and older refraction lines in the vicinity. The models show a highly complex crust whose thickness varies between 50 and 60 km along the profile. The seismic velocity is high, increasing from 5.85 km s(^-l) near the surface to 7.4 km s(^-1) at the base of the crust. Lateral velocity variations are seen in the mid-upper crust while discontinuous reflectors and diffracting bodies are seen at 30 km depth. In the central/northern part of the line the crust thickens and there is a change in seismic velocity. Using other geophysical information from the region, two hypotheses are put forward for interpreting this part of the seismic model. The first is the presence of a large igneous intrusion, and the second is the existence of a shear zone or tectonic boundary cutting Line 1. Further work will be required to confirm either or both of these hypotheses.
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Books on the topic "Bothnian Sea"

1

Merentutkimuslaitos, ed. Field experiment SEA ICE -85 in mid-winter in the Bay of Bothnia. Helsinki: Finnish Institute of Marine Research, 1987.

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Agency, National Geospatial-intelligence. PUB116 2006 NGA List of Lights: Baltic Sea w/ Kattegat Belts and Sound, Gulf of Bothnia. 2nd ed. ProStar Publications, Inc., 2006.

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NIMA. List of Lights: Radio Aids and Fog Signals, 2005 Baltic Sea with Kettegat Belts and Sound, Gulf of Bothnia (PUB116). ProStar Publications, 2005.

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NIMA. PUB116 List of Lights: Radio Aids and Fog Signals, 2002 Baltic Sea with Kettegat Belts and Sound, Gulf of Bothnia. ProStar Publications, Inc., 2002.

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Agency, National Geospatial-intelligence. List of Lights 116: 2006 Radio Aids and Fog Signals - Baltic Sea (with Kattegat, Belts, and Sound and Gulf of Bothnia). ProStar Publications, Inc., 2004.

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Agency, National Geospatial Intelligence. List of Lights 116:2009 Radio Aids and Fog Signals- Baltic Sea (with Kattegat, Belts, and Sound of Sound and Gulf of Bothnia) (20). ProStar Publications, Inc., 2009.

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Book chapters on the topic "Bothnian Sea"

1

Johansson, Kajsa, Peter Sigray, Tobias Backström, and Carin Magnhagen. "Stress Response and Habituation to Motorboat Noise in Two Coastal Fish Species in the Bothnian Sea." In The Effects of Noise on Aquatic Life II, 513–21. New York, NY: Springer New York, 2016. http://dx.doi.org/10.1007/978-1-4939-2981-8_62.

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Edwards, Henrik. "Pilot Assignment to Ships in the Sea of Bothnia." In Energy, Natural Resources and Environmental Economics, 411–25. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-12067-1_23.

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Nordman, M., A. Peltola, M. Bilker-Koivula, and S. Lahtinen. "Past and Future Sea Level Changes and Land Uplift in the Baltic Sea Seen by Geodetic Observations." In International Association of Geodesy Symposia. Berlin, Heidelberg: Springer Berlin Heidelberg, 2020. http://dx.doi.org/10.1007/1345_2020_124.

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Abstract We have studied the land uplift and relative sea level changes in the Baltic Sea in northern Europe. To observe the past changes and land uplift, we have used continuous GNSS time series, campaign-wise absolute gravity measurements and continuous tide gauge time series. To predict the future, we have used probabilistic future scenarios tuned for the Baltic Sea. The area we are interested in is Kvarken archipelago in Finland and High Coast in Sweden. These areas form a UNESCO World Heritage Site, where the land uplift process and how it demonstrates itself are the main values. We provide here the latest numbers of land uplift for the area, the current rates from geodetic observations, and probabilistic scenarios for future relative sea level rise. The maximum land uplift rates in Fennoscandia are in the Bothnian Bay of the Baltic Sea, where the maximum values are currently on the order of 10 mm/year with respect to the geoid. During the last 100 years, the land has risen from the sea by approximately 80 cm in this area. Estimates of future relative sea level change have considerable uncertainty, with values for the year 2100 ranging from 75 cm of sea level fall (land emergence) to 30 cm of sea-level rise.
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Nilsson, Per, Lars Brydsten, Magnus Enell, and Mats Jansson. "Turnover of Chloroorganic Substances in a Bothnian Sea Recipient Receiving Bleached Kraft Pulp Mill Effluents." In ENVIRONMENTAL FATE and EFFECTS of PULP and PAPER MILL EFFLUENTS, 203–18. CRC Press, 2020. http://dx.doi.org/10.1201/9780367812690-20.

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"No. 14443. Agreement between Sweden and Finland concerning the delimitation of the continental shelf in the Gulf of Bothnia, the Bothnian Sea, the Åland Sea, and the northernmost part of the Baltic Sea. Signed at Stockholm on 29 September 1972." In Treaty Series 1887, 461. UN, 2000. http://dx.doi.org/10.18356/56640fc4-en-fr.

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Conference papers on the topic "Bothnian Sea"

1

Aispure, G. "Copepod limnocalanus macrurus mating in relation to vertical migrations and aspects of feeding rates in the Bothnian Sea (Baltic Sea)." In 2006 IEEE US/EU Baltic International Symposium on Integrated Ocean Observation Syst. for Managing Global & Regional Ecosys.Marine Resch. IEEE, 2006. http://dx.doi.org/10.1109/baltic.2006.7266164.

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Wenta, Marta, Agnieszka Herman, David Brus, and Konstantinos Doulgeris. "Winter atmospheric boundary layer observations and numerical modelling over sea ice in the coastal zone of the Bothnian Bay (Baltic Sea)." In The 3rd International Electronic Conference on Atmospheric Sciences. Basel, Switzerland: MDPI, 2020. http://dx.doi.org/10.3390/ecas2020-08122.

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Lu, Han‐xing, and Larry Lines. "Processing enhancements for Gulf of Bothnia marine data." In SEG Technical Program Expanded Abstracts 1994. Society of Exploration Geophysicists, 1994. http://dx.doi.org/10.1190/1.1822851.

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Mikkola, Eeva, Jaakko Heinonen, Markus Kankainen, Toni Hekkala, and Juha Kurkela. "Multi-Platform Concepts for Combining Offshore Wind Energy and Fish Farming in Freezing Sea Areas: Case Study in the Gulf of Bothnia." In ASME 2018 37th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/omae2018-77677.

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Climate change together with increasing demand for space pose a challenge to energy and food production at sea areas. Co-location of offshore renewable energy production, aquaculture and other blue economy activities can answer the need for more sustainable marine space utilization while reducing and dividing costs of the different activities. This paper presents a case study of a multi-use platform that combines wind energy and fish farming in the Gulf of Bothnia, where the sea freezes every winter. A marine spatial planning (MSP) tool is used to find suitable locations for the multi-use platform with respect to economic potential of energy and nutrient production, structural solutions and environmental impact. The tool is used to visualize site selection criteria based on geographic information system (GIS) data such as seabed data, wind and wave data and ice data as well as protected marine areas. Production potential scenarios for the multi-use platform at different scales are calculated. Synergies of combining offshore wind energy and fish farming are discussed.
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Zvyagin, Petr, and Jaakko Heinonen. "Application of Confidence Regions to Ice Ridge Keel Data Statistical Assessment." In ASME 2017 36th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/omae2017-62253.

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Sets of measurements of underwater ridge parts usually contain a limited amount of data. Outcomes need to be made while relying on small sample sizes. In this event, the chance of making inaccurate estimations increases. This paper proposes to use stochastic confidence regions in the estimation of the unknown parameters of keel depths. A model for a random variable with a lognormal distribution for keel depths is assumed. Regions for the mean and standard deviation of keel depths are obtained from Mood’s and minimum-area confidence regions for parameters of the normally distributed random variable. Conservative safety probability of non-exceeding the critical keel depth in one random interaction of the ridge with structure is estimated. An algorithm for statistically assessment of ice ridge keel data by means of confidence region building is here offered. The assessment of a set of ridge keel depths for the Gulf of Bothnia (Baltic Sea) is performed.
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Nelis, Sander, Kristjan Tabri, and Pentti Kujala. "Interaction of Ice Force in Ship-Ship Collision." In ASME 2015 34th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/omae2015-41351.

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The maritime transportation system in the Northern Baltic Sea (NBS) is complex and operates under varying environmental conditions. The most challenging conditions relate to the presence of ice-cover, which for the NBS e.g. for the Gulf of Finland or Bay of Bothnia, can remain up to several months. The number of maritime accidents in these two areas is the highest during winter season, which can involve accidents like groundings, collisions, damages due to the ice etc. The paper presents the model to predict the ice interaction in ship-ship collision dynamics. The ice forces are included in the time-domain simulation model and also in a simplified model based on the momentum conservation. The simplified model is proposed for a rapid estimation of increase in deformation energy due to the presence of ice forces. The analysis shows that the ice influence depends strongly on the ship mass, ice thickness and collision speed. The maximum increase in the deformation energy in the studied collision scenarios was up to 19%.
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Teigen, Sigurd Henrik, Joakim K. Lindvall, Ilija Samardzija, and Roar I. Hansen. "Station-Keeping Trials in Ice: Ice and Metocean Conditions." In ASME 2018 37th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/omae2018-78620.

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In March 2017, Statoil performed station-keeping trials in drifting ice in the Bay of Bothnia with the two anchor handling tug supply vessels Magne Viking and Tor Viking. During the trials observations of ice and metocean conditions were performed via a range of platforms and techniques. The purpose of the observations was to document the main physical parameters affecting the station-keeping vessel and ice management vessel, as well as giving tactical information on ice conditions and input to simultaneous numerical simulations. Measurements of meteorological parameters (wind speed, wind direction, air temperature, etc.) were done from the two vessels and supplemented with manual observations. Ice drift was independently measured by drifting ice trackers and ADCPs (also measuring ocean current) moored on the sea bed. Measurements of ice thickness were carried out with moored Ice Profiling Sensors (IPSs) and manual ice core samples, which were also analyzed for salinity and temperature profiles. The IPS ice thickness data was later processed together with the ice drift to provide 2D spatial data. The deepest ice ridge keels ranged from 5.4 m at the site with the most benign ice conditions to 10.9 m at the most severe site. Ridge frequency also increased from 2 ridges km−1 to 16 ridges km−1 at the most severe site (given a keel threshold of 3 m). In the present study, statistical summaries of the different time series collected at the sites of the station-keeping trials are presented, highlighting the variability in the ice conditions. Using the vessel tracks and overall drift of the broken channels, ice thickness and drift measurements are classified as being inside or outside the managed ice zone.
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