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  • 1. Akhtar, Naveed
    et al.
    Krug, Amelie
    Brauch, Jennifer
    Arsouze, Thomas
    Dieterich, Christian
    SMHI, Research Department, Oceanography.
    Ahrens, Bodo
    European marginal seas in a regional atmosphere-ocean coupled model and their impact on Vb-cyclones and associated precipitation2019In: Climate Dynamics, ISSN 0930-7575, E-ISSN 1432-0894, Vol. 53, no 9-10, p. 5967-5984Article in journal (Refereed)
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  • 2.
    Algotsson, Josefina
    et al.
    SMHI, Core Services.
    Edman, Moa
    SMHI, Research Department, Oceanography.
    Förslag till statusklassning av parameter 9.5 Sötvatteninflöde och vattenutbyte i kustvatten och vatten i övergångszon: En jämförelse mellan Kustzonsmodellens naturliga och normala uppsättning2019Report (Other academic)
    Abstract [en]

    Around half of Sweden's electricity generation consists of hydropower, which is produced in about 2000 power plants. The largest drainage of water from land takes place during the spring and the water is stored in reservoirs for electricity production during the winter. This change in the natural runoff has major effects on the aquatic ecosystems and is considered to be one of the biggest environmental challenges for Swedish waterways and lakes.There is currently no guidance for status classification of hydromorphological parameters in coastal waters according to the Water Framework Directive. SMHI was commissioned by the water authorities to produce a proposal for class boundaries and classification for parameter 9.5 Freshwater inflow and water exchange in coastal water and water in transition zone in accordance with the regulations stated by the Swedish Agency for Marine and Water Management in the document HVMFS 2013:19. The hydrological model S-HYPE and the oceanographic Coastal Zone Model were used to study the changes in fresh water supply as well as fresh water content, salinity and water age of the surface water caused by regulation of water flow on land.In general, the regulation of water flow on land has led to an increase in the fresh water content by 2% along the Norrlands coast and a corresponding decrease in the fresh water content on the west coast. Typically, the regulation of water on land leads to a lower freshwater supply to the coast during spring and summer and a higher freshwater supply to the coast in the autumn and winter compared to a scenario with a natural land runoff.The natural background variation, as defined by ± 2 MAD (Median Absolute Deviation), and the Maximum Absolute Deviation, MAA, were used to construct 5 status classes.

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  • 3.
    Almroth, Elin
    et al.
    SMHI, Research Department, Oceanography.
    Skogen, Morten
    Institute of Marine Research, Bergen, Norway..
    Sehested Hansen, Ian
    Institute of Marine Research, Bergen, Norway..
    Stipa, Tapani
    FMI.
    Niiranen, Susa
    FMI.
    The Year 2006 An Eutrophication Status Report of the North Sea, Skagerrak Kattegat and the Baltic Sea: A demonstration Project2008Report (Other academic)
    Abstract [en]

    This is the third year joint status report for the North Sea, Skagerrak, Kattegat and the Baltic Sea area (Fig. 1) carried out by SMHI, IMR, DHI and FIMR as a part of the project BANSAI, supported by the Nordic Council of Ministers’ Sea and Air Group. The aim of the demonstration project is to integrate marine observations and eutrophication model simulations in an annual eutrophication assessment of the Baltic and the North seas. The present report is mainly based on model estimates of some of the indicators suggested by the OSPAR Common Procedure (c.f. Appendix) for the identification of the eutrophication status of the maritime area (OSPAR, 2005). This report serve as a basis for the on-going discussions about the ecological quality indicators included in the assessment, and the way to merge results from different models and observations for the assessment.Estimations of river discharges and model results are used to describe the degree of nutrient enrichment (Category I) defined by the riverine loadings of nitrogen and phosphorus, and winter surface concentrations and ratios of DIN and DIP. The direct effects of nutrient enrichment during the growing season (Category II) are described in terms of the mean and maximum chlorophyll-a concentrations and model estimations of primary production. The ratio between diatoms and flagellates is used as an indicator of region specific phytoplankton indicator species (Category II). The indirect effects of nutrient enrichment (Category III) are discussed in terms of oxygen depletion in bottom waters. Estimations of region specific background concentrations and threshold values are gathered from the literature (Helcom, 2006; OSPAR, 2005) and used for the model assessment. The four model systems used for the joint assessment (Fig. 2) cover different parts of the North Sea, Skagerrak, Kattegat and the Baltic Sea area. Detailed descriptions of the models may be found on the web-sites presented below the figure.In section 2 the key messages from this assessment will be presented. In section 3, each country gives a brief observations overview for 2006 and some references to other sources and reports that might be useful for the readers. The methods of the assessment are described in section 4. Statistical characteristics of model results and in-situ data are presented in section 5 and the model assessment of eutrophication status is done in section 6. Conclusions and comments to the assessment are presented in section 7.

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  • 4.
    Almroth-Rosell, Elin
    et al.
    SMHI, Research Department, Oceanography.
    Edman, Moa
    SMHI, Research Department, Oceanography.
    Eilola, Kari
    SMHI, Research Department, Oceanography.
    Meier, Markus
    SMHI, Research Department, Oceanography.
    Sahlberg, Jörgen
    SMHI, Professional Services.
    Modelling nutrient retention in the coastal zone of an eutrophic sea2016In: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 13, no 20, p. 5753-5769Article in journal (Refereed)
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  • 5.
    Almroth-Rosell, Elin
    et al.
    SMHI, Research Department, Oceanography.
    Eilola, Kari
    SMHI, Research Department, Oceanography.
    Hordoir, Robinson
    SMHI, Research Department, Oceanography.
    Meier, Markus
    SMHI, Research Department, Oceanography.
    Hall, Per O. J.
    Transport of fresh and resuspended particulate organic material in the Baltic Sea - a model study2011In: Journal of Marine Systems, ISSN 0924-7963, E-ISSN 1879-1573, Vol. 87, no 1, p. 1-12Article in journal (Refereed)
    Abstract [en]

    A fully coupled high-resolution 3-dimensional biogeochemical-physical ocean model including an empirical wave model was used to investigate the long-term average (1970-2007) distributions and transports of resuspended matter and other types of suspended organic matter in the Baltic Sea. Modelled bottom types were compared to observations and the results showed that the model successfully managed to capture the horizontal, as well as the vertical, distribution of the different bottom types: accumulation, transport and erosion bottoms. The model also captured well the nutrient element contents in the sediments. On average the largest contribution of resuspended organic carbon to the transport of total organic carbon is found at erosion and transport bottoms. Although the relative transport of resuspended organic carbon at deeper accumulation bottoms in general is low (< 10% of total), the central parts of the sub-basins act on average as sinks that import organic matter while the more shallow areas and the coastal regions acts as sources of organic carbon in the water column. This indicates that the particulate organic matter produced in erosion and transport areas might be kept in suspension long enough to be transported and settle in less energetic areas, i.e. on accumulation bottoms. (C) 2011 Elsevier B.V. All rights reserved.

  • 6.
    Almroth-Rosell, Elin
    et al.
    SMHI, Research Department, Oceanography.
    Eilola, Kari
    SMHI, Research Department, Oceanography.
    Kuznetsov, Ivan
    Hall, Per O. J.
    Meier, Markus
    SMHI, Research Department, Oceanography.
    A new approach to model oxygen dependent benthic phosphate fluxes in the Baltic Sea2015In: Journal of Marine Systems, ISSN 0924-7963, E-ISSN 1879-1573, Vol. 144, p. 127-141Article in journal (Refereed)
    Abstract [en]

    The new approach to model the oxygen dependent phosphate release by implementing formulations of the oxygen penetration depths (OPD) and mineral bound inorganic phosphorus pools to the Swedish Coastal and Ocean Biogeochemical model (SCOBI) is described. The phosphorus dynamics and the oxygen concentrations in the Baltic proper sediment are studied during the period 1980-2008 using SCOBI coupled to the 3D-Rossby Centre Ocean model. Model data are compared to observations from monitoring stations and experiments. The impact from oxygen consumption on the determination of the OPD is found to be largest in the coastal zones where also the largest OPD are found. In the deep water the low oxygen concentrations mainly determine the OPD. Highest modelled release rate of phosphate from the sediment is about 59 x 10(3) t P year(-1) and is found on anoxic sediment at depths between 60-150 m, corresponding to 17% of the Baltic proper total area. The deposition of organic and inorganic phosphorus on sediments with oxic bottom water is larger than the release of phosphorus, about 43 x 10(3) t P year(-1). For anoxic bottoms the release of total phosphorus during the investigated period is larger than the deposition, about 19 x 10(3) t P year(-1). In total the net Baltic proper sediment sink is about 23.7 x 10(3) t P year(-1). The estimated phosphorus sink efficiency of the entire Baltic Sea is on average about 83% during the period. (C) 2014 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).

  • 7.
    Almroth-Rosell, Elin
    et al.
    SMHI, Research Department, Oceanography.
    Skogen, Morten D.
    A North Sea and Baltic Sea Model Ensemble Eutrophication Assessment2010In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 39, no 1, p. 59-69Article in journal (Refereed)
    Abstract [en]

    A method to combine observations and an ensemble of ecological models is suggested to produce a eutrophication assessment. Using threshold values and methodology from the Oslo and Paris Commissions (OSPAR) and the Helsinki Commission (HELCOM), four models are combined to assess eutrophication for the Baltic and North Seas for the year 2006. The assessment indicates that the entire southeastern part of the North Sea, the Kattegat, the Danish Straits, the Gulf of Finland, and the Gulf of Riga as well as parts of the Arkona Basin, the Bornholm Basin, and the Baltic proper may be classified as problem areas. The Bothnian Bay and parts of the Baltic proper, the Bornholm Basin, and the Arkona Basin are classified as potential problem areas. This method is a useful tool for the classification of eutrophication; however, the results depend on the threshold values, and further work is needed within both OSPAR and HELCOM to harmonize these values.

  • 8.
    Almroth-Rosell, Elin
    et al.
    SMHI, Research Department, Oceanography.
    Skogen, Morten
    Sehested Hansen, Ian
    DHI Water and Environments.
    Stipa, Tapani
    University of Helsinki.
    Niiranen, Susa
    Stockholm University.
    The Year 2006 An Environmental Status report of the North Sea, Skagerrak, Kattegat and the Baltic Sea2007In: BANSAI- The Baltic and North Sea marine environmental modelling Asessment Initaiative / [ed] the Nordic Council of Ministers’ Sea and Air Group, 2007Conference paper (Other academic)
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  • 9.
    Almroth-Rosell, Elin
    et al.
    SMHI, Research Department, Oceanography.
    Wåhlstrom, Irene
    SMHI, Research Department, Oceanography.
    Hansson, Martin
    SMHI, Core Services.
    Vali, Germo
    Eilola, Kari
    SMHI, Core Services.
    Andersson, Pia
    SMHI, Core Services.
    Viktorsson, Lena
    SMHI, Core Services.
    Hieronymus, Magnus
    SMHI, Research Department, Oceanography.
    Arneborg, Lars
    SMHI, Research Department, Oceanography.
    A Regime Shift Toward a More Anoxic Environment in a Eutrophic Sea in Northern Europe2021In: Frontiers in Marine Science, E-ISSN 2296-7745, Vol. 8, article id 799936Article in journal (Refereed)
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    A Regime Shift Toward a More Anoxic Environment in a Eutrophic Sea in Northern Europe
  • 10.
    Alvarez, Elena Alabarces
    et al.
    SMHI, Research Department, Oceanography.
    Klemm, Kerstin
    Hoppenrath, Mona
    Cembella, Allan
    John, Uwe
    Karlson, Bengt
    SMHI, Research Department, Oceanography.
    Temporal and spatial distribution of epibenthic dinoflagellates in the Kattegat-Skagerrak, NE Atlantic-Focus on Prorocentrum lima and Coolia monotis2022In: Harmful Algae, ISSN 1568-9883, E-ISSN 1878-1470, Vol. 118, article id 102318Article in journal (Refereed)
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    Temporal and spatial distribution of epibenthic dinoflagellates in the Kattegat-Skagerrak, NE Atlantic-Focus on Prorocentrum lima and Coolia monotis
  • 11. Aminot, A
    et al.
    Kirkwood, D
    Carlberg, Stig
    SMHI, Research Department, Oceanography.
    The QUASIMEME laboratory performance studies (1993-1995): Overview of the nutrients section1997In: Marine Pollution Bulletin, ISSN 0025-326X, E-ISSN 1879-3363, Vol. 35, no 1-6, p. 28-41Article in journal (Refereed)
    Abstract [en]

    The QUASIMEME Project (1993-1996) was established to assist European laboratories to improve the data they produce in marine monitoring programmes. Through laboratory performance Studies (with six-monthly reports), workshops and expert visits the programme was fully interactive. There were five rounds of laboratory performance studies. For the nutrient section, in which about 50 laboratories took part, the reference materials distributed to the participants consisted of standard solutions of nutrients and seawater samples stabilized by autoclaving. The material included low and high concentrations typical of those encountered in coastal seawater; at least two samples with different concentrations were distributed in each round. Robust statistics were used to determine the means and standard deviations for each set of results. For inorganic nutrients, the assessment of the data for bias and precision was based mainly on a Z- and P-scoring system in which targets of +/- 6% were allocated to the high concentrations, likewise +/- 12.5% to the low concentrations. This overview discusses overall performance separately for nitrate plus nitrite, nitrite, ammonia, phosphate, total nitrogen and total phosphorus, and classifies the performance of individual laboratories in each round, while maintaining their anonymity. Performance for nitrate plus nitrite and nitrite improved steadily and these determinands are now fully under control; at the end of the programme, standard deviations (SD) for nitrate plus nitrite were 0.2 mu mol l(-1) at low concentration and 0.6 mu mol l(-1) (4%) at high concentration, and for nitrite they were 0.03 mu mol l(-1) and 0.06 mu mol l(-1) (5%) respectively. Phosphate showed a somewhat stable level of performance with SD of 0.06 mu mol l(-1) and 0.10 mu mol l(-1) (10%) at low and high concentrations respectively, but this could be improved. Ammonia proved the most difficult to determine, and in spite of a substantial improvement at the beginning of the exercise, this determinand is not under control in many laboratories. At low concentrations, ammonia shows a positive bias of 0.2 mu mol l(-1) and a SD of 0.3 mu mol l(-1), while at high concentrations SD reaches 0.5 mu mol l(-1) (20%). For total nitrogen (TN) and total phosphorus (TP), the exercises show that only two thirds of the participants produced consistent data for TN, and less than half of them produced consistent data for TP. (C) 1997 Elsevier Science Ltd. All rights reserved.

  • 12. Amir-Heidari, Payam
    et al.
    Arneborg, Lars
    SMHI, Research Department, Oceanography.
    Lindgren, J. Fredrik
    Lindhe, Andreas
    Rosen, Lars
    Raie, Mohammad
    Axell, Lars
    SMHI, Research Department, Oceanography.
    Hassellov, Ida-Maja
    A state-of-the-art model for spatial and stochastic oil spill risk assessment: A case study of oil spill from a shipwreck2019In: Environment International, ISSN 0160-4120, E-ISSN 1873-6750, Vol. 126, p. 309-320Article in journal (Refereed)
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  • 13. Amortegui, Julio Cesar Espana
    et al.
    Pekar, Heidi
    Retrato, Mark Dennis Chico
    Persson, Malin
    Karlson, Bengt
    SMHI, Research Department, Oceanography.
    Bergquist, Jonas
    Zuberovic-Muratovic, Aida
    LC-MS/MS Analysis of Cyanotoxins in Bivalve Mollusks-Method Development, Validation and First Evidence of Occurrence of Nodularin in Mussels (Mytilus edulis) and Oysters (Magallana gigas) from the West Coast of Sweden2023In: Toxins, E-ISSN 2072-6651, Vol. 15, no 5, article id 329Article in journal (Refereed)
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    LC-MS/MS Analysis of Cyanotoxins in Bivalve Mollusks—Method Development, Validation and First Evidence of Occurrence of Nodularin in Mussels (Mytilus edulis) and Oysters (Magallana gigas) from the West Coast of Sweden
  • 14. Andersen, Jesper H.
    et al.
    Axe, Philip
    SMHI, Research Department, Oceanography.
    Backer, Hermanni
    Carstensen, Jacob
    Claussen, Ulrich
    Fleming-Lehtinen, Vivi
    Jarvinen, Marko
    Kaartokallio, Hermanni
    Knuuttila, Seppo
    Korpinen, Samuli
    Kubiliute, Aiste
    Laamanen, Maria
    Lysiak-Pastuszak, Elzbieta
    Martin, Georg
    Murray, Ciaran
    Mohlenberg, Flemming
    Nausch, Guenther
    Norkko, Alf
    Villnas, Anna
    Getting the measure of eutrophication in the Baltic Sea: towards improved assessment principles and methods2011In: Biogeochemistry, ISSN 0168-2563, E-ISSN 1573-515X, Vol. 106, no 2, p. 137-156Article in journal (Refereed)
    Abstract [en]

    The eutrophication status of the entire Baltic Sea is classified using a multi-metric indicator-based assessment tool. A total of 189 areas are assessed using indicators where information on reference conditions (RefCon), and acceptable deviation (AcDev) from reference condition could be combined with national monitoring data from the period 2001-2006. Most areas (176) are classified as 'affected by eutrophication' and only two open water areas and 11 coastal areas are classified as 'unaffected by eutrophication'. The classification is made by application of the recently developed HELCOM Eutrophication Assessment Tool (HEAT), which is described in this paper. The use of harmonized assessment principles and the HEAT tool allows for direct comparisons between different parts of the Baltic Sea despite variations in monitoring activities. The impaired status of 176 areas is directly related to nutrient enrichment and elevated loads from upstream catchments. Baltic Sea States have implemented nutrient management strategies since years which have reduced nutrient inputs. However, eutrophication is still a major problem for large parts of the Baltic Sea. The 2007 Baltic Sea Action Plan is projected to further reduce nutrient inputs aiming for a Baltic Sea unaffected by eutrophication by 2021.

  • 15. Andersen, Jesper H.
    et al.
    Murray, Ciaran
    Kaartokallio, Hermanni
    Axe, Philip
    SMHI, Research Department, Oceanography.
    Molvaer, Jarle
    A simple method for confidence rating of eutrophication status classifications2010In: Marine Pollution Bulletin, ISSN 0025-326X, E-ISSN 1879-3363, Vol. 60, no 6, p. 919-924Article in journal (Refereed)
    Abstract [en]

    We report the development of a methodology for assessing confidence in ecological status classifications. The method presented here can be considered as a secondary assessment, supporting the primary assessment of eutrophication or ecological status. The confidence assessment is based on scoring the quality of the indicators on which the primary assessment is made. This represents a first step towards linking status classification with information regarding their accuracy and precision. Applied to an existing data set used for assessment of eutrophication status of the Baltic Sea (including the Kattegat and Danish Straits) we demonstrate that confidence in the assessment is Good or High in 149 out of 189 areas assessed (79%). Contrary to our expectations, assessments of the open parts of the Baltic Sea have a higher confidence than assessments of coastal waters. We also find that in open waters of the Baltic Sea, some biological indicators have a higher confidence than indicators representing physical-chemical conditions. In coastal waters, phytoplankton, submerged aquatic vegetation and indicators of physical-chemical conditions have a higher confidence than indicators of the quality of benthic invertebrate communities. Our analyses also show that the perceived weaknesses of eutrophication assessments are due more to Low confidence in reference conditions and acceptable deviations, rather than in the monitoring data. (C) 2010 Elsevier Ltd. All rights reserved.

  • 16. Anderson., D. M
    et al.
    Karlson, Bengt
    SMHI, Research Department, Oceanography.
    Preservatives and methods for algal cell enumeration2017In: Harmful Algal Blooms (HABs) and Desalination: A Guide to Impacts, Monitoring and Management / [ed] Anderson D. M., S. F. E. Boerlage, M. B. Dixon, Paris: Intergovernmental Oceanographic Commission of UNESCO , 2017, p. 509-517Chapter in book (Refereed)
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  • 17. Andersson, Agneta
    et al.
    Meier, Markus
    SMHI, Research Department, Oceanography.
    Ripszam, Matyas
    Rowe, Owen
    Wikner, Johan
    Haglund, Peter
    Eilola, Kari
    SMHI, Research Department, Oceanography.
    Legrand, Catherine
    Figueroa, Daniela
    SMHI, Core Services.
    Paczkowska, Joanna
    Lindehoff, Elin
    Tysklind, Mats
    Elmgren, Ragnar
    Projected future climate change and Baltic Sea ecosystem management2015In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 44, p. S345-S356Article in journal (Refereed)
    Abstract [en]

    Climate change is likely to have large effects on the Baltic Sea ecosystem. Simulations indicate 2-4 degrees C warming and 50-80 % decrease in ice cover by 2100. Precipitation may increase similar to 30 % in the north, causing increased land runoff of allochthonous organic matter (AOM) and organic pollutants and decreased salinity. Coupled physical-biogeochemical models indicate that, in the south, bottom-water anoxia may spread, reducing cod recruitment and increasing sediment phosphorus release, thus promoting cyanobacterial blooms. In the north, heterotrophic bacteria will be favored by AOM, while phytoplankton production may be reduced. Extra trophic levels in the food web may increase energy losses and consequently reduce fish production. Future management of the Baltic Sea must consider the effects of climate change on the ecosystem dynamics and functions, as well as the effects of anthropogenic nutrient and pollutant load. Monitoring should have a holistic approach, encompassing both autotrophic (phytoplankton) and heterotrophic (e.g., bacterial) processes.

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  • 18.
    Andersson, Helén
    et al.
    SMHI, Research Department, Oceanography.
    Eriksson Bram, Lena
    SMHI, Core Services.
    Hjerdt, Niclas
    SMHI, Core Services.
    Lindström, Göran
    SMHI, Research Department, Hydrology.
    Löptien, Ulrike
    SMHI, Research Department, Oceanography.
    Strömqvist, Johan
    SMHI, Research Department, Hydrology.
    Översikt av beräkningsmodeller för bedömning av fiskodlingars näringsämnesbelastning på sjöar, vattendrag, magasin och kustvatten2016Report (Other academic)
    Abstract [sv]

    Den här rapporten är en kunskapssammanställning som utförts av SMHI på uppdrag av Havs- och Vattenmyndigheten. Den utgör inte något ställningstagande från Havs- och vattenmyndighetens sida. Rapporten försöker att sammanfatta den problematik som associeras med näringsämnesbelastningar från fiskodlingar i öppna kassar, vilka typer av beräkningar som kan behöva göras för att få en uppfattning om hur dessa kan påverka miljön samt några olika typer av modeller för detta ändamål.

    Fisk-, alg- och skaldjursodling är en växande industri runt om i världen som kan ge såväl näringsrik och hälsosam mat som arbetstillfällen. En nackdel med framförallt fiskodling i öppna kassar är att den kan innebära en påfrestning för vattenmiljön. De näringsämnen som ofta släpps ut från odlingen kan bidra till den övergödningsproblematik som redan finns i många sjöar och havsområden. Det är därför av största vikt att få en god uppskattning av den förväntade storleken på utsläppen förknippade med en öppen odling samt hur de kan tänkas förändra vattenkvaliteten på odlingsplatsen och dess närhet. Beräkningsmodeller kan vara till god hjälp vid bedömningen.

    Fiskar utsöndrar lösta näringsämnen och från odlingskassarna faller det också ut partikulärt organiskt material i form av fekalier och oätet foder. Storleken på näringsämneskällorna behöver beräknas och det finns modeller av olika komplexitet för att uppskatta detta. Storleken på det partikulära avfallet är viktigt dels för att det bidrarmed näringsämnen till vattnet och dels för att det kan ge upphov till ansamlingar av organiskt material på bottnen. När det organiska materialet bryts ner förbrukas syre och om ansamlingarna blir omfattande finns en risk för att det uppstår syrebrist vid bottnen. Om svavelväte bildas kan det orsaka skador på såväl den odlade fisken som det lokala ekosystemet. Odlingen kan också bidra till en försämrad vattenkvalitet i sin omgivning genom att tillgången av lösta näringsämnen blir större och därmed ge en ökad algproduktion. Den ökade algproduktionen skall i sin tur brytas ner och kan i förlängningen bidra till syrebristproblematiken.

    Det finns ett antal modeller som är specifikt utvecklade för fiskodlingar i öppna kassar och de tar i olika hög grad upp den beskrivna problematiken. Rapporten innehåller detaljerade genomgångar av några av modeller för att visa på styrkor och svagheter kring olika angreppsätt. Den innehåller också sammanfattningar av några vanligt förekommande modeller som använts internationellt vid bedömning av fiskodlingars miljöpåverkan. För att minska den negativa påverkan på vattenmiljön från har det också utvecklats recirkulerande system för odling. Rapporten tar inte upp belastning från den typen av fiskodlingar. Om utsläppen från ett sådant system är känt kan dock vattenkvalitetsmodeller användas för att se effekten av utsläpp från en punktkälla.

    Rapporten sammanfattar ett antal vattenkvalitetsmodeller för sjöar, vattendrag, kust och hav. En vattenkvalitetsmodell behöver inte nödvändigtvis vara utvecklad för att beskriva konsekvenser av fiskodlingar men bör kunna hantera frågeställningar som uppkommer vid bedömningar av övergödningsrisk vid utsläpp från en punktkälla. Den behöver därför kunna simulera parametrar såsom förändringen av näringsämneskoncentrationer, primärproduktion, siktdjup och syrgashalter på olika nivåer i vattenmassan. Modeller för den här typen av uppskattningar finns också i olika komplexitetsgrad och för olika skalor i tid och rum.

    Vid modellering är en god tillgång till observationer en förutsättning för pålitliga modellresultat och behövs såväl för att driva och kalibrera modellen som för validering av modellresultaten. Det är viktigt att tillgängliga data håller god kvalitet. En noggrann analys och beskrivning av den tillgängliga databasen hjälper därmed till att bedöma tillförlitligheten av modellsimuleringarna.

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  • 19.
    Andersson, Helén
    et al.
    SMHI, Research Department, Oceanography.
    Wallman, Patrik
    SMHI, Research Department, Hydrology.
    Donnelly, Chantal
    SMHI, Research Department, Hydrology.
    Visualization of hydrological, physical and biogeochemical modelling of the Baltic Sea using a GeoDomeTM2011Report (Other academic)
    Abstract [en]

    The ECOSUPPORT-project aims to help policy makers by supplying state-of-the-art research on the state of the Baltic Sea under different scenarios of nutrient supply, pressure from fisheries and impact of climate change. In order to make the research results accessible, a new form of scientific communication has been tested. Presentation of research data and physical, chemical and biogeochemical processes on land and in the sea were made using a special visualization platform, Uniview, which was projected onto a cupola-shaped screen inside an inflatable, enclosed dome. The visualization has been tested on different audiences including policy makers, politicians, researchers and university students. Overall, the response has been overwhelmingly positive with the audience expressing the view that the used visualization technique enhanced their understanding and receptiveness. This view was shared with the scientific presenters.

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  • 20.
    Andersson, Lars
    et al.
    SMHI, Core Services.
    Carlberg, Stig
    SMHI, Core Services.
    Edler, Lars
    SMHI, Research Department, Oceanography.
    Fogelqvist, Elisabet
    SMHI.
    Fonselius, Stig
    SMHI, Research Department, Oceanography.
    Fyrberg, Lotta
    SMHI, Core Services.
    Palmén, Håkan
    SMHI.
    Sjöberg, Björn
    SMHI, Core Services.
    Zagradkin, Danuta
    SMHI.
    Haven runt Sverige 1991. Rapport från SMHI, Oceanografiska Laboratoriet, inklusive PMK - utsjöprogrammet1992Report (Other academic)
    Abstract [en]

    This report describe SMHls environmental monitoring in the open sea areas around Sweden, from the Skagerrak to the northem part of the Bothnian Sea  A great part of the results from the project described here are also reported as a national Swedish contribution to the Baltic Monitoring Programme (BMP) of the Helsinki Commission (HELCOM). Physical, chemical and biological parameters are studied in water samples, zoobenthos is studied in sediment grab samples and samples of fish and mussels are collected for the determination of harmful substances in the Kattegat, the Sound (Öresund), the Baltic Proper and the Gulf of Bothnia.

    The temperature of the sea surface layer was higher than normal most part of the year, just as in 1989. In the entire sea area the temperatures were 1- 3 °C above the long term mean value for the period 1979 - 1989. The oxygen conditions in the south eastern Kattegat once again were unfavorable in late summer and early autumn. However, despite the unusually calm autumn with only weak mixing of the water masses the oxygen concentrations increased again and the situation never was serious. Also in the Baltic Proper the bad oxygen situation in the deep water prevailed in several basins the whole year. No major inflow of oxygen rich water occurred to ventilate the deep basins. In the Bornholm Basin hydrogen sulphide was present under the halocline (with an extension into the Hanö Bight) the whole year with the exception of the August cruise. In the Gdansk Basin there is no longer any stratification and oxygen is mixed into the water from the atmosphere. This has improved the conditions in the bottom water. In the Eastern Gotland Basin hydrogen sulphide has been present in the bottom water for more than 13 years continuously. The Northem Central Basin, including the Landsort Deep, and the Western Central Basin were free from hydrogen sulphide the whole year. Nutrient conditions did not show any remarkable or unexpected changes during 1990. During the winter period phosphate and nitrate were present in about normal concentrations, which decreased to near detection limit during the production period in the spring and early summer and then increased again during autumn. The petroleum hydrocarbons showed during the spring roughly the same concentrations as during the previous years, whereas the autumn values were normal in the surface water only and all other values were high or very high. The reason for this has not been identified.

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  • 21.
    Andersson, Lars
    et al.
    SMHI, Core Services.
    Carlberg, Stig
    SMHI, Core Services.
    Fogelqvist, Elisabet
    SMHI.
    Fonselius, Stig
    SMHI, Research Department, Oceanography.
    Fyrberg, Lotta
    SMHI, Core Services.
    Palmén, Håkan
    SMHI.
    Zagradkin, Danuta
    SMHI.
    Yhlén, Bengt
    SMHI.
    Program för miljökvalitetsövervakning – PMK: Utsjöprogram under 19901991Report (Other academic)
    Abstract [en]

    The projectThis report describes a project for environmental monitoring in the sea areas around Sweden, from the Kattegat to the northern part of the Bothnian Sea. SMHI carries out this project based on a contractual arrangement with the National Swedish Environment Protection Agency (SEPA) and the project is part of the national programme for environmental monitoring (PMK). The greater part of the results from the project described here is also reported as a national Swedish contribution to the Baltic Monitoring Programme (BMP) of the Helsinki Commission (HELCOM).

    The monitoring is carried out through a number of regular cruises in the Kattegat, the Sound (Öresund), the Baltic Proper and the Gulf ofBothnia. Physical, chemical and biological parameters are studied in water samples, zoobenthos is studied in sediment grab samples and samples of fish and mussels are collected for the determination of harmful substances.

    The work is entirely integrated with the regular oceanographical programme of SMHI. By this arrangement the result of the SMHI programme is made available also for the national monitoring. Consequently, this report contains a lot more information than is really financed by the SEPA monitoring budget.

    ResultsThe winter of 1989 - 90 was very mild; it was in fact the fourth mild winter in sequence! The sea ice cover was small; By and large, it was only the Bothnian Bay that was covered and this ice broke up about two weeks earlier than usual. The first part of 1990 was warm and windy and yielded at lot of  precipitation, particularly in the southern part of Sweden. The spring was early and warmer than normal. In May and later the weather was more unstable and the summer had changing weather and somewhat low temperatures. The autumn started as calm and rainy, but ended in December as mild and windy.

    The temperature of the sea surface layer was higher than normal most part of the year, just as it was in 1989. lnfact, the temperatures were 1- 3 °C above the long term mean value for the period 1979- 1989 in the entire area.

    The oxygen conditions in the south eastern Kattegat once again turned into an unfavorable situation in late summer and early autumn. However, despite the unusually calm autumn with only weak mixing of the water masses the oxygen concentrations increased again and the situation never was serious. Also in the Baltic Proper the bad oxygen situation in the deep water prevailed in several basins the whole year. No major infiow of oxygen rich water occurred to ventilate the deep basins. In the Bornholm Basin hydrogen sulphide was present under the halocline (with an extension into the Hanö Bight) the whole year with the exception of the August cruise. In the Gdansk Basin there is no longer any stratification and oxygen is mixed into hte water from the surfacelayer. This has improved the conditions int he bottom water. However, in the Eastern Gotland Basin hydrogen sulphide has been present in the bottom water for more than 13 years continuously. The Northern Central Basin, including the Landsort Deep, and the Western Central Basin were free from hydrogen sulphide the whole year.

    Nutrient conditions did not show any remarkable or unexpected changes during 1990. During the winter period phosphate and nitrate were present in about normal concentrations, which decreased to near detection limit during the production period in the spring and early summer and then increased again during autumn.

    The analyses of petroleum hydrocarbons showed slightly lower concentrations for the spring as compared to the results from the 1980-ties. This indicates that the load of oil pollution of the Baltic and the Kattegat had not changed significantly. However, the results from the autumn sampling were strikingly different. Although the surface samples showed normal concentrations the results from 10 m (and 30 m) were higher. The reason for this could not be identified but it is unlikely to be a contamination of the samples.

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  • 22.
    Andersson, Lars
    et al.
    SMHI, Core Services.
    Edler, Lars
    SMHI, Research Department, Oceanography.
    Sjöberg, Björn
    SMHI, Core Services.
    The conditions of the seas around Sweden: Report from activities in 19921993Report (Other academic)
    Abstract [en]

    This report describes same aspects of the hydrographical conditions in the open sea areas around Sweden , based on SMHis environmental monitoring program during 1992. Due to the warm winter the mean sea surface temperature during spring was about 2 °C higher than normal. In Skagerrak events with very high nutrient concentrations accurred close to the Danish coast. No severe oxygen deficits were present in the Kattegat,  the lowest value recorded was 0.8 ml/l in the Laholm Bight during September. During autumn silicate in Kattegat surface water was below the detection limit which is very unusual. No major inflow of high saline water to the Baltic has occurred since 1977 and the salinity in the Gotland Deep at the end of 1992 was lowest ever recorded.

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    The conditions of the seas around Sweden. Report from activities in 1992.
  • 23.
    Andersson, Lars
    et al.
    SMHI, Core Services.
    Rahm, Lars
    SMHI, Research Department, Oceanography.
    THERMALLY DRIVEN CIRCULATION WITHIN AN EXPERIMENTAL ENCLOSURE1990In: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 30, no 2, p. 111-129Article in journal (Refereed)
  • 24.
    Andersson, Sandra
    et al.
    SMHI, Core Services.
    Bärring, Lars
    SMHI, Research Department, Climate research - Rossby Centre.
    Landelius, Tomas
    SMHI, Research Department, Atmospheric remote sensing.
    Samuelsson, Patrick
    SMHI, Research Department, Climate research - Rossby Centre.
    Schimanke, Semjon
    SMHI, Research Department, Oceanography.
    SMHI Gridded Climatology2021Report (Other academic)
    Abstract [en]

    A gridded dataset (SMHI Gridded Climatology - SMHIGridClim) has been produced forthe years 1961 - 2018 over an area covering the Nordic countries on a grid with 2.5 kmhorizontal resolution. The variables considered are the two meter temperature and twometer relative humidity on 1, 3 or 6 hour resolution, varying over the time periodcovered, the daily minimum and maximum temperatures, the daily precipitation and thedaily snow depth. The gridding was done using optimal interpolation with the gridppopen source software from the Norwegian Meteorological Institute.Observations for the analysis are provided by the Swedish, Finish and Norwegianmeteorological institutes, and the ECMWF. The ECA&D observation data set (e.g. usedfor the gridded E-OBS dataset) was considered for inclusion but was left out because ofcomplications with time stamps and accumulation periods varying between countries andperiods. Quality check of the observations was performed using the open source softwareTITAN, also developed at the Norwegian Meteorological Institute.The first guess to the optimal interpolation was given by statistically downscaledforecasts from the UERRA-HARMONIE reanalysis at 11 km horizontal resolution. Thedownscaling was done to fit the output from the operational MEPS NWP system at 2.5km with a daily and yearly variation in the downscaling parameters.The quality of the SMHIGridClim dataset, in terms of annual mean RMSE, was shown tobe similar to that of gridded datasets covering the other Nordic countries; “seNorge”from Norway and the dataset “FMI_ClimGrid” from Finland.

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    RMK_118 SMHI Gridded Climatology
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    RMK_118 SMHI Gridded Climatology_appendixA_observations
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    RMK_118 SMHI Gridded Climatology_appendixB_errors
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    RMK_118 SMHI Gridded Climatology_appendixC_scripts
  • 25.
    Arneborg, Lars
    et al.
    SMHI, Research Department, Oceanography.
    Höglund, Anders
    SMHI, Research Department, Oceanography.
    Axell, Lars
    SMHI, Research Department, Oceanography.
    Lensu, Mikko
    Ljungman, Olof
    Mattsson, Johan
    Oil drift modeling in pack ice - Sensitivity to oil-in-ice parameters2017In: Ocean Engineering, ISSN 0029-8018, E-ISSN 1873-5258, Vol. 144, p. 340-350Article in journal (Refereed)
  • 26.
    Arneborg, Lars
    et al.
    SMHI, Research Department, Oceanography.
    Jansson, Par
    Staalstrom, Andre
    Broström, Göran
    Tidal Energy Loss, Internal Tide Radiation, and Local Dissipation for Two-Layer Tidal Flow over a Sill2017In: Journal of Physical Oceanography, ISSN 0022-3670, E-ISSN 1520-0485, Vol. 47, no 7, p. 1521-1538Article in journal (Refereed)
  • 27.
    Arneborg, Lars
    et al.
    SMHI, Research Department, Oceanography.
    Pemberton, Per
    SMHI, Research Department, Oceanography.
    Grivault, Nathan
    SMHI, Research Department, Oceanography.
    Axell, Lars
    SMHI, Research Department, Oceanography.
    Saraiva, Sofia
    SMHI, Research Department, Oceanography.
    Mulder, Erik
    SMHI, Research Department, Oceanography.
    Fredriksson, Sam
    SMHI, Research Department, Oceanography.
    Hydrographic effects in Swedish waters of future offshore wind power scenarios2024Report (Other academic)
    Abstract [en]

    For two future scenarios on the expansion of offshore wind power in the Baltic Sea and the North Sea, SMHI has investigated how the hydrography, i.e. temperatures, salinities, currents and stratification, may be affected. Effects were induced by wind stress reductions on the sea surface and by the increased friction and turbulence in the water from wind turbine foundations.

    The results show that an expansion of wind power in the Baltic Sea in general will cause a shallowed halocline, and increased deep water salinities and temperatures, due to decreasing winds behind the wind farms that lead to decreasing vertical mixing in the Baltic Sea. However, the magnitude of changes shows a strong sensitivity to assumptions about the wind stress reduction at the sea surface, and the size of wind power expansion.

    The wind farm scenarios are prepared in collaboration with the Swedish Agency for Marine and Water Management (SwAM) and are based on marine plans from Sweden’s neighbouring countries as well as new proposals for suitable wind power areas that SwAM will present to the government in 2024. In one scenario, Scenario 1, it is assumed that there will be offshore wind in all proposed areas, while in the second scenario, Scenario 2, it is assumed that only 50% of areas will be developed. Both scenarios represent large offshore wind power developments that will probably not be realized in reality. The scenarios have been investigated by running an ocean model for the Baltic Sea and the North Sea with and without wind power for the period 1985 – 2016 to evaluate how different the sea would have looked if the wind power had been built in 1985 according to the scenarios.

    There is still lack of knowledge about how wind farms affect the wind at the sea surface, so this work is based on studies of existing wind farms in the North Sea, where studies show a reduction of the wind by around 8% and an area that extends about 30 km behind the wind farm under stable atmospheric conditions. When the atmosphere is unstable, which it often is in winter, the reduction is less. In order to get an estimate of the largest and smallest possible impact of wind power on the sea, we have therefore, for both scenarios, assumed that the reduction of wind only exists in summer and no reduction during winter (minimum possible impact), or that the reduction exists all year round (upper limit of impact).

    The magnitude of expected changes is very dependent on the assumptions on the wind wakes, and the response is much smaller for the minimum possible impact than for the upper limit impact. The real response for these scenarios probably lays somewhere in between these estimates.

    For the scenario with less wind farms in Swedish waters (Scenario 2), the influences on salinity, temperature, and halocline are reduced relative to Scenario 1 in a manner that may be expected from the difference in total wind farm areas in the Baltic Sea in the two scenarios.

    The model results also show that the wind power foundations (modelled as bottom mounted) cause a salinity decrease in the Baltic Sea deep water, probably due to increased friction and mixing in the entrance region to the Baltic Sea. This effect is much smaller than the wind wake effect when it is active during the whole year.

    The Baltic Sea surface salinity, surface temperature, and currents show much smaller and less robust changes than the salinity and temperature changes in the deepwater.

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    Hydrographic effects in Swedish waters of future offshore wind power scenarios
  • 28.
    Axe, Philip
    SMHI, Research Department, Oceanography.
    Oceanographic applications of coastal radar2013Report (Other academic)
    Abstract [en]

    This report documents the 2010 Coastal Radar Workshop organised by the Swedish Meteorological and Hydrological Institute with support from the Swedish Environmental Protection Agency. The aim of the report is to provide background information on coastal oceanographic radar for a wider professional audience and to provide a basis for further Nordic cooperation in the field of oceanographic (coastal) radar with the ultimate aim of establishing a Nordic network covering (initially) the shared waters of the Skagerrak and Kattegat.Information on currents in near real time is seldom available when needed by many day to day applications and services. Data are needed for safe and efficient ship routing in narrow areas of hightraffic such as in the northern Kattegat, Danish Straits, Bornholm Strait and the Gulf of Finland. At the entrances of major ports and where [environmentally] dangerous cargos are carried currentinformation can be of crucial importance. For this reason the Swedish Maritime Administration maintains current observations in critical areas. However, these are point measurements and in the waters mentioned above topography may alter currents both in strength and direction in nearby areas. Hence, complementary spatial information on the behaviour of currents is preferable.Access to high quality, spatially resolved current information is critical both for effective oil spill containment and greatly increases the chances for successful outcomes of search and rescue operations. Combining data from models and observations will reduce the search area in rescue operations and make planning and combat of oil spill operations more efficient. In addition, areal near real time current observations are likely to promote research and development related to fish larvae transports, the spread of alien species, improve oceanographic models and lead to the better understanding of ocean and coastal sea processes.The present workshop highlights and extends the knowledge base on European and US experiences, user needs and available technical systems for areal current observations. Taking into account thatNordic views are usually coherent, opportunities to coordinate and cooperate in establishing and running an operational pilot system at a Nordic level seem realistic. The workshop intends to lay the foundation for carrying this work further.

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  • 29.
    Axe, Philip
    SMHI, Research Department, Oceanography.
    Temporal and spatial monitoring of eutrophication variables in CEMP2008Report (Other academic)
    Abstract [en]

    The OSPAR Revised Eutrophication Monitoring Programme (ETG 05/3/Info.1-E) requests that nutrient "monitoring should include sufficient samples to confirm that the maximum winter nutrient concentration has been determined", while para. 7 of the Terms of Reference for the preparation of guidance on the spatial and temporal resolution of monitoring for nutrients and eutrophication effects (ICG 003) states that "there are at least nine different water types covered by the OSPAR Maritime Area"..."guidance must, therefore, be at least complex enough to cover each type with sufficient clarity to guide contracting parties in their evaluation of the temporal and spatial coverage required to adequately assess the relevant water body".This document summarises the national reports submitted to the OSPAR Intersessional Correspondence Group on Eutrophication Monitoring, and highlights common problems faced in the monitoring of (primarily) inorganic nutrients and chlorophyll. In addition, it presents tests of different approaches to solving the spatial and temporal sampling problems associated with delivering marine eutrophication data.Based on tests of model data, monthly sampling appears adequate to give a good estimate of annual mean concentrations. Buoy data suggests that this would not be sufficient where there is tidal variability. It was not possible to determine maximum concentrations through a practical ship sampling scheme, or by using extreme value statistics.The optimum sampling programme to observe rapid events is likely to be a combination of ferrybox systems, which appear to be reliable and give both good spatial and temporal coverage, combined with buoy observations. To ensure data of sufficient quality, these must be controlled against conventional research vessel observations. Research vessels still have a role in seasonal mapping, and in providing data of sufficient quality for trend analysis from a large area. This is likely to remain so, at leastuntil technologies such as gliders and optical nutrient sensors become widely available and capable of delivering reliable, high quality data.

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  • 30.
    Axe, Philip
    et al.
    SMHI, Research Department, Oceanography.
    Hansson, Martin
    SMHI, Core Services.
    Håkansson, Bertil
    SMHI, Research Department, Oceanography.
    The National Monitoring Programme in the Kattegat and Skagerrak2004Report (Other academic)
    Abstract [en]

    To facilitate the development of the OSPAR eutrophication monitoring programme, this report presents the statistical strength of trends reported in the 2002 Common Procedure Report1. After correcting nutrient records to a reference salinity of 30 psu (to compensate for the effects of dilution), ortho-phosphate concentration exhibits a significant negative trend in the inshore Kattegat and Skagerrak. Significant decreases in silicate were observed in all areas. These changes caused changes in Redfield and other nutrient ratios. Indirect indicators of eutrophication (autumn, bottom oxygen concentration; growing-season chlorophyll-a concentration) exhibited significant trends. Chlorophyll-a concentration increased in the Skagerrak, while oxygen concentration decreased in all areas, apart from the inshore Kattegat.Spatial characteristics of the study area were tested using probability mapping. The Kattegat was found to be well represented by 8 divisions, while 4 areas were suitable Skagerrak.Changes in the current monitoring programme were not recommended. Increasing sampling frequency could interfere with the statistical independence of measurements – an assumption for the validity of trend calculations. Filling gaps in the existing time series improves the statistical significance of observed trends. This requires effective data exchange between monitoring institutions, and possibly data archaeology.

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  • 31.
    Axe, Philip
    et al.
    SMHI, Research Department, Oceanography.
    Lindow, Helma
    SMHI, Core Services.
    Hydrographic Conditions Around Offshore Banks2005Report (Other academic)
    Abstract [en]

    This report details the results of an investigation into hydrographic and hydrochemical conditions over ten offshore banks around the coast of south Sweden. Four of these banks are situated in the Kattegat. The remainder lie in the southern and western Baltic Proper. The investigation included field sampling, where each bank was visited on one occasion, and the temperature and salinity structure mapped while the concentrations of nutrients were measured. These data were analysed, and results compared and complemented with predictions from operational numerical models (for currents and waves). The banks are areas with strong horizontal gradients in temperature and salinity. They influence the large scale circulation, steering mean currents through the deeper water, resulting in the mean currents over the banks being weak. The influence of short term wind events are significant however, with intense, short-lived currents occurring over the banks. Nutrient concentrations in the waters above the banks were very similar to those in the adjacent basins. Immediately over the bottom however, silicate concentrations were often higher than at similar depths away from the banks. Similarly, oxygen saturation immediately above the bottom was frequently lower than in mid-water at the same depth. In the Kattegat, large areas are at risk from seasonal oxygen deficiency. The shallow nature of the banks however often means that they escape the worst impacts.

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  • 32.
    Axe, Philip
    et al.
    SMHI, Research Department, Oceanography.
    Wesslander, Karin
    SMHI, Core Services.
    Kronsell, Johan
    SMHI, Core Services.
    Confidence rating for OSPAR COMP2012Report (Other academic)
    Abstract [en]

    With the adoption of the Marine Strategy Framework Directive and the Water Framework Directive, EU Member States are obliged to achieve “Good” or “Good Environmental” Status within a certain time frame, or be obliged to take remedial action. There is therefore a need to quantify the quality of the monitoring programmes on which such status assessments are based, as a part of assessing the confidence in the status assessment. Within the framework of the OSPAR Convention on the Protection of the North East Atlantic, Germany and the Netherlands presented a suggestion for how such an assessment could be made. This report documents the application of this methodology to stations in the Swedish National Monitoring Programme within the OSPAR area, and also within the Sound, which may in future be included in the Greater North Sea region under the Marine Strategy Directive. The variability of eutrophication parameters with salinity was examined. In the Kattegat, inorganic nutrient variability was least at the highest salinities, suggesting that a reliable status assessment could be made more easily with data from this region, for example, rather than in the dynamic near coast region. Assessing the coverage of the existing monitoring programme, it was found that horizontal gradients in assessment parameters (generally seasonal averages) varied by less than about 30% between stations, which suggests that the programme has reasonable spatial coverage, though additional stations would improve matters. Looking at each station individually, the current vertical sampling resolution appears adequate for most parameters, apart from chlorophyll a and inorganic nutrients during the growing season. Temporal coverage is adequate for the total nutrient concentrations, but is insufficient for the inorganic nutrients and chlorophyll a, as well as for the deep water oxygen concentration in the Sound. The poor temporal coverage of chlorophyll a and inorganic nutrients could be relatively easily improved by the addition of a two channel (nitrate + nitrite, and orthophosphate) autoanalyser onto the existing ferrybox platforms in use in these waters. Addressing these problems using traditional measuring platforms and buoys would be more costly. The poor temporal coverage of chlorophyll a and inorganic nutrients could be relatively easily improved by the addition of a two channel (nitrate + nitrite, and orthophosphate) autoanalyser onto the existing ferrybox platforms in use in these waters. Addressing these problems using traditional measuring platforms and buoys would be more costly.

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  • 33.
    Axell, Lars
    SMHI, Research Department, Oceanography.
    BSRA-15: A Baltic Sea Reanalysis 1990–20042013Report (Other academic)
    Abstract [en]

    Oceanographic observations are often of high quality but are available only with low resolution in time and space. On the other hand, model fields have high resolution in time and space but are not necessarily in agreement with observations. To bridge the gap between these very different kinds of data sets, a reanalysis can be made, which means that fixed versions of the numerical model and the data assimilation system are used to analyse a period of several years. This report describes an oceanographic reanalysis covering the period 1990 to 2004 (15 whole years). The horizontal resolution is 3 nautical miles in the Baltic Sea and 12 nautical miles in the North Sea, and the vertical resolution varies between 4 meters near the surface to 60 meters in the deepest part (up to 24 vertical layers). The time resolution of the reanalysis product is 6 hours. The numerical ocean model used is HIROMB (High-Resolution Operational Model for the Baltic), version 3.0. The data assimilation method used in this reanalysis is the Successive Corrections Method (SCM) for salinity and temperature, whereas ice observations in terms of ice charts were simply interpolated. The result looks good in terms of sea levels, ice fields, and salinity and temperature structure, whereas currents have not been validated. This oceanographic reanalysis was probably the first one ever for the Baltic Sea (when it was done in 2005) and may serve as a starting point before longer, more advanced reanalyses are produced.

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  • 34.
    Axell, Lars
    SMHI, Research Department, Oceanography.
    On the variability of Baltic Sea deepwater mixing1998In: JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS, Vol. 103, no C10, p. 21667-21682Article in journal (Refereed)
    Abstract [en]

    Historical oceanographic data from the period 1964-1997 from two deep subbasins (the Gotland Deep and the Landsort Deep) in the Baltic Sea have been analyzed, by using a budget method on stagnant periods, with respect to vertical diffusion and vertical energy flux density in the deep water. It was found that the rate of deepwater mixing varied with the seasons, with higher rates in fall and winter compared to spring and summer. Further, according to the analyzed data, the downward flux density of energy available for vertical diffusion decreased with increasing depth in the Gotland Deep. In the Landsort Deep, however, the flux density increased somewhat, probably because of topographic concentration of the energy, before decreasing toward the bottom. Moreover, the vertical energy flux densities were compared with the expected flux density from the local wind. It is proposed that in the Gotland Deep, which is outside the coastal boundary layer, the observed deepwater mixing is dominated by the energy input from the wind via inertial currents and internal waves. In the Landsort Deep, however, which is within the coastal boundary layer, the expected flux density of energy from the local wind cannot explain the observed rate of work against the buoyancy forces. It is proposed that the active coastal boundary layer plays a central role in the transfer of energy to mixing processes in the deep water.

  • 35.
    Axell, Lars
    SMHI, Research Department, Oceanography.
    Wind-driven internal waves and Langmuir circulations in a numerical ocean model of the southern Baltic Sea2002In: Journal of Geophysical Research, ISSN 0148-0227, E-ISSN 2156-2202, Vol. 107, no C11, article id 3204Article in journal (Refereed)
    Abstract [en]

    [1] A one-dimensional numerical ocean model of the southern Baltic Sea is used to investigate suitable parameterizations of unresolved turbulence and compare with available observations. The turbulence model is a k-epsilon model that includes extra source terms P-IW and P-LC of turbulent kinetic energy (TKE) due to unresolved, breaking internal waves and Langmuir circulations, respectively. As tides are negligible in the Baltic Sea, topographic generation of internal wave energy (IWE) is neglected. Instead, the energy for deepwater mixing in the Baltic Sea is provided by the wind. At each level the source term P-IW is assumed to be related to a vertically integrated pool of IWE, E-0, and the buoyancy frequency N at the same level, according to P-IW (z) proportional to E0Ndelta (z). This results in vertical profiles of epsilon (the dissipation rate of TKE) and K-h (the eddy diffusivity) according to epsilon proportional to N-delta and K-h proportional to Ndelta-2 below the main pycnocline. Earlier observations are inconclusive as to the proper value of delta, and here a range of values of delta is tested in hundreds of 10-year simulations of the southern Baltic Sea. It is concluded that delta = 1.0 +/- 0.3 and that a mean energy flux density to the internal wave field of about (0.9 +/- 0.3) x 10(-3) W m(-2) is needed to explain the observed salinity field. In addition, a simple wind-dependent formulation of the energy flux to the internal wave field is tested, which has some success in describing the short- and long-term variability of the deepwater turbulence. The model suggests that similar to16% of the energy supplied to the surface layer by the wind is used for deepwater mixing. Finally, it is also shown that Langmuir circulations are important to include when modeling the oceanic boundary layer. A simple parameterization of Langmuir circulations is tuned against large-eddy simulation data and verified for the Baltic Sea.

  • 36.
    Axell, Lars
    et al.
    SMHI, Research Department, Oceanography.
    Liu, Ye
    SMHI, Research Department, Oceanography.
    Application of 3-D ensemble variational data assimilation to a Baltic Sea reanalysis 1989-20132016In: Tellus. Series A, Dynamic meteorology and oceanography, ISSN 0280-6495, E-ISSN 1600-0870, Vol. 68, article id 24220Article in journal (Refereed)
    Abstract [en]

    A 3-D ensemble variational (3DEnVar) data assimilation method has been implemented and tested for oceanographic data assimilation of sea surface temperature (SST), sea surface salinity (SSS), sea ice concentration (SIC), and salinity and temperature profiles. To damp spurious long-range correlations in the ensemble statistics, horizontal and vertical localisation was implemented using empirical orthogonal functions. The results show that the 3DEnVar method is indeed possible to use in oceanographic data assimilation. So far, only a seasonally dependent ensemble has been used, based on historical model simulations. Near-surface experiments showed that the ensemble statistics gave inhomogeneous and anisotropic horizontal structure functions, and assimilation of real SST and SIC fields gave smooth, realistic increment fields. The implementation was multivariate, and results showed that the cross-correlations between variables work in an intuitive way, for example, decreasing SST where SIC was increased and vice versa. The profile data assimilation also gave good results. The results from a 25-year reanalysis showed that the vertical salinity and temperature structure were significantly improved, compared to both dependent and independent data.

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  • 37.
    Axell, Lars
    et al.
    SMHI, Research Department, Oceanography.
    Ljungman, Olof
    SMHI, Research Department, Oceanography.
    A One-Equation Turbulence Model for Geophysical Applications: Comparison with Data and the k - epsilon Model2001In: Environmental Fluid Mechanics, ISSN 1567-7419, E-ISSN 1573-1510, Vol. 1, no 1, p. 71-106Article in journal (Refereed)
    Abstract [en]

    A one-equation turbulence model is presented, in which the turbulent kinetic energy k is calculated with a transport equation whereas the turbulent length scale l is calculated with an algebraic expression. The value of l depends on the local stratification and reduces to the classical kappa vertical bar z vertical bar scaling for unstratified flows near a wall, where vertical bar z vertical bar is the distance to the wall. The length scale decreases during stable stratification, and increases for unstable stratification compared to the neutral case. In the limit of strong stable stratification, the so-called buoyancy length scale proportional to k(1/2)N(-1) is obtained, where N is the buoyancy frequency. The length scale formulation introduces a single model parameter which is calibrated against experimental data. The model is verified extensively against laboratory measurements and oceanic data, and comparisons are made with the two-equation k-epsilon model. It is shown that the performance of the proposed k model is almost identical to that of the k-epsilon model. In addition, the stability functions of Launder are revisited and adjusted to obtain better agreement with recent data.

  • 38. Bal, S.
    et al.
    Schimanke, Semjon
    SMHI, Research Department, Oceanography.
    Spangehl, T.
    Cubasch, U.
    On the robustness of the solar cycle signal in the Pacific region2011In: Geophysical Research Letters, ISSN 0094-8276, E-ISSN 1944-8007, Vol. 38, article id L14809Article in journal (Refereed)
    Abstract [en]

    The potential role of the stratosphere for the 11-year solar cycle signal in the Pacific region is investigated by idealized simulations using a coupled atmosphere-ocean general circulation model. The model includes a detailed representation of the stratosphere and accounts for changes in stratospheric heating rates from prescribed time dependent variations of ozone and spectrally high resolved solar irradiance. Three transient simulations are performed spanning 21 solar cycles each. The simulations use slightly different ozone perturbations representing uncertainties of solar induced ozone variations. The model reproduces the main features of the 20th century observed solar response. A persistent mean sea level pressure response to solar forcing is found for the eastern North Pacific extending over North America. Moreover, there is evidence for a La Nina-like response assigned to solar maximum conditions with below normal SSTs in the equatorial eastern Pacific, reduced equatorial precipitation, enhanced off-equatorial precipitation and an El Nino-like response a couple of years later, thus confirming the response to solar forcing at the surface seen in earlier studies. The amplitude of the solar signal in the Pacific region depends to a great extent on the choice of the centennial period averaged. Citation: Bal, S., S. Schimanke, T. Spangehl, and U. Cubasch (2011), On the robustness of the solar cycle signal in the Pacific region, Geophys. Res. Lett., 38, L14809, doi:10.1029/2011GL047964.

  • 39. Bal, Sourabh
    et al.
    Schimanke, Semjon
    SMHI, Research Department, Oceanography.
    Spangehl, Thomas
    Cubasch, Ulrich
    Enhanced residual mean circulation during the evolution of split type sudden stratospheric warming in observations and model simulations2018In: Journal of Earth System Science, E-ISSN 0973-774X, Vol. 127, no 5, article id 68Article in journal (Refereed)
  • 40. Bal, Sourabh
    et al.
    Schimanke, Semjon
    SMHI, Research Department, Oceanography.
    Spangehl, Thomas
    Cubasch, Ulrich
    Variable influence on the equatorial troposphere associated with SSW using ERA-Interim2017In: Journal of Earth System Science, E-ISSN 0973-774X, Vol. 126, no 2, article id UNSP 19Article in journal (Refereed)
  • 41. Bartolino, Valerio
    et al.
    Tian, Huidong
    Bergstrom, Ulf
    Jounela, Pekka
    Aro, Eero
    Dieterich, Christian
    SMHI, Research Department, Oceanography.
    Meier, Markus
    SMHI, Research Department, Oceanography.
    Cardinale, Massimiliano
    Bland, Barbara
    Casini, Michele
    Spatio-temporal dynamics of a fish predator: Density-dependent and hydrographic effects on Baltic Sea cod population2017In: PLOS ONE, E-ISSN 1932-6203, Vol. 12, no 2, article id e0172004Article in journal (Refereed)
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  • 42. Bauer, Barbara
    et al.
    Gustafsson, Bo G.
    Hyytiainen, Kari
    Meier, Markus
    SMHI, Research Department, Oceanography.
    Mueller-Karulis, Baerbel
    Saraiva, Sofia
    SMHI, Research Department, Oceanography.
    Tomczak, Maciej T.
    Food web and fisheries in the future Baltic Sea2019In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 48, no 11, p. 1337-1349Article in journal (Refereed)
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  • 43. Bauer, Barbara
    et al.
    Meier, Markus
    SMHI, Research Department, Oceanography.
    Casini, Michele
    Hoff, Ayoe
    Margonski, Piotr
    Orio, Alessandro
    Saraiva, Sofia
    SMHI, Research Department, Oceanography.
    Steenbeek, Jeroen
    Tomczak, Maciej T.
    Reducing eutrophication increases spatial extent of communities supporting commercial fisheries: a model case study2018In: ICES Journal of Marine Science, ISSN 1054-3139, E-ISSN 1095-9289, Vol. 75, no 4, p. 1306-1317Article in journal (Refereed)
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  • 44. Bauer, Barbara
    et al.
    Meier, Markus
    SMHI, Research Department, Oceanography.
    Casini, Michele
    Hoff, Ayoe
    Margonski, Piotr
    Orio, Alessandro
    Saraiva, Sofia
    SMHI, Research Department, Oceanography.
    Steenbeek, Jeroen
    Tomczak, Maciej T.
    Reducing eutrophication increases spatial extent of communities supporting commercial fisheries: a model case study (vol 75, pg 1155, 2018)2018In: ICES Journal of Marine Science, ISSN 1054-3139, E-ISSN 1095-9289, Vol. 75, no 3, p. 1155-1155Article in journal (Refereed)
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  • 45. Berdalet, Elisa
    et al.
    Anderson, Clarissa
    Banas, Neil
    Davis, Timothy
    Clarke, David
    Jeong, Hae Jin
    Karlson, Bengt
    SMHI, Research Department, Oceanography.
    Kudela, Raphael M.
    Lapointe, Brian
    Lim, Po Teen
    Martinelli Filho, Jose Eduardo
    Serrao, Ester
    Siano, Raffaele
    Silke, Joe
    Trainer, Vera
    van Tussenbroek, Brigitta
    Wood, Susie
    Yniguez, Aletta
    Miloslavich, Patricia
    Enevoldsen, Henrik
    GLOBALHAB (IOC-UNESCO AND SCOR): LATINAMERICA CONTRIBUTION TO THE INTERNATIONAL COORDINATION FOR SOUND KNOWLEDGE OF HABS AND MANAGEMENT OF THEIR IMPACTS2021In: Phycologia, ISSN 0031-8884, E-ISSN 2330-2968, Vol. 60, p. 86-87Article in journal (Refereed)
  • 46. Berdalet, Elisa
    et al.
    Kudela, Raphael
    Urban, Ed
    Enevoldsen, Henrik
    Banas, Neil S.
    Bresnan, Eileen
    Burford, Michele
    Davidson, Keith
    Gobler, Christopher J.
    Karlson, Bengt
    SMHI, Research Department, Oceanography.
    Lim, Po Teen
    Mackenzie, Lincoln
    Montresor, Marina
    Trainer, Vera L.
    Usup, Gires
    Yin, Kedong
    GlobalHAB A New Program to Promote International Research, Observations, and Modeling of Harmful Algal Blooms in Aquatic Systems2017In: Oceanography, ISSN 1042-8275, Vol. 30, no 1, p. 70-81Article in journal (Refereed)
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  • 47. Berdalet, Elisa
    et al.
    Pavaux, Anne-Sophie
    Abos-Herrandiz, Rafael
    Travers, Muriel
    Appere, Gildas
    Vila, Magda
    Thomas, Jeremy
    de Haro, Luc
    Estrada, Marta
    Inmaculada Medina-Perez, Noemi
    Viure, Laia
    Karlson, Bengt
    SMHI, Research Department, Oceanography.
    Lemee, Rodolphe
    Environmental, human health and socioeconomic impacts of Ostreopsis spp. Blooms in the NW Mediterranean2022In: Harmful Algae, ISSN 1568-9883, E-ISSN 1878-1470, Vol. 119, article id 102320Article in journal (Refereed)
  • 48. Bjork, Goran
    et al.
    Nordberg, Kjell
    Arneborg, Lars
    SMHI, Research Department, Oceanography.
    Bornmalm, Lennart
    Harland, Rex
    Robijn, Ardo
    Odalen, Malin
    Seasonal oxygen depletion in a shallow sill fjord on the Swedish west coast2017In: Journal of Marine Systems, ISSN 0924-7963, E-ISSN 1879-1573, Vol. 175, p. 1-14Article in journal (Refereed)
  • 49. Blenckner, T
    et al.
    Omstedt, Anders
    SMHI, Research Department, Oceanography.
    Rummukainen, Markku
    SMHI, Research Department, Climate research - Rossby Centre.
    A Swedish case study of contemporary and possible future consequences of climate change on lake function2002In: Aquatic Sciences, ISSN 1015-1621, E-ISSN 1420-9055, Vol. 64, no 2, p. 171-184Article in journal (Refereed)
    Abstract [en]

    A physical lake model was employed to obtain a basis of discussing the impact of climate variability and climate change on the ecology of Lake Erken, Sweden. The validity of this approach was tested by running the PROBE-lake model for a 30-year period (STD) with observed meteorological data. The lake is adequately modelled, as seen in the comparison with actual lake observations. The validated lake model was then forced with meteorological data obtained from a regional climate model (RCM) with a horizontal resolution of 44 km for present (CLTR) and 2 x CO(2) (SCEN) climate conditions. The CUR lake simulation compares reasonably with the STD. Applying the SCEN simulation leads to a climate change scenario for the lake. The physical changes include elevated temperatures, shorter periods of ice cover combined with two of ten years being totally ice-free, and changes in the mixing regime. The ecological consequences of the physical simulation results are derived from the historical dataset of Lake Erken. Consequences of a warmer climate could imply increased nutrient cycling and lake productivity. The results suggest that an application of RCMs with a suitable resolution for lakes in combination with physical lake models allows projection of the responses of lakes to a future climate.

  • 50. Blenckner, Thorsten
    et al.
    Ammar, Yosr
    Mueller-Karulis, Baerbel
    Niiranen, Susa
    Arneborg, Lars
    SMHI, Research Department, Oceanography.
    Li, Qiang
    The Risk for Novel and Disappearing Environmental Conditions in the Baltic Sea2021In: Frontiers in Marine Science, E-ISSN 2296-7745, Vol. 8, article id 745722Article in journal (Refereed)
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    The Risk for Novel and Disappearing Environmental Conditions in the Baltic Sea
1234567 1 - 50 of 505
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