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  • 1.
    Almroth-Rosell, Elin
    et al.
    SMHI, Forskningsavdelningen, Oceanografi.
    Eilola, Kari
    SMHI, Forskningsavdelningen, Oceanografi.
    Hordoir, Robinson
    SMHI, Forskningsavdelningen, Oceanografi.
    Meier, Markus
    SMHI, Forskningsavdelningen, Oceanografi.
    Hall, Per O. J.
    Transport of fresh and resuspended particulate organic material in the Baltic Sea - a model study2011Ingår i: Journal of Marine Systems, ISSN 0924-7963, E-ISSN 1879-1573, Vol. 87, nr 1, s. 1-12Artikel i tidskrift (Refereegranskat)
    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.

  • 2.
    Dieterich, Christian
    et al.
    SMHI, Forskningsavdelningen, Oceanografi.
    Schimanke, Semjon
    SMHI, Forskningsavdelningen, Oceanografi.
    Wang, Shiyu
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Väli, Germo
    SMHI, Forskningsavdelningen, Oceanografi.
    Liu, Ye
    SMHI, Forskningsavdelningen, Oceanografi.
    Hordoir, Robinson
    SMHI, Forskningsavdelningen, Oceanografi.
    Höglund, Anders
    SMHI, Forskningsavdelningen, Oceanografi.
    Meier, Markus
    SMHI, Forskningsavdelningen, Oceanografi.
    Evaluation of the SMHI coupled atmosphere-ice-ocean model RCA4-NEMO2013Rapport (Övrigt vetenskapligt)
    Abstract [sv]

    Den regionala kopplade atmosfär-is-havsmodellen RCA4-NEMO som utvecklats vid SMHI, utvärderas baserat på en ERA40-återanalys. Utvecklingen av den regionala klimatmodellen fortsätter men en första utvärdering presenteras här för att informera om aktuell status.RCA4-NEMO i aktuell status innehåller två modellkomponenter. Den regionala atmosfärsmodellen RCA4 täcker hela Europa och är tvåvägskopplad till en is-hav-modell för Nordsjön och Östersjön baserat på NEMO. Den används för tillfället för nedskalning av CMIP5-scenarier för detta århundrade för Nordsjön och Östersjön. Som en del av utvärderingen av RCA4-NEMO presenteras en analys och diskussion av hindcast-körning 1970-1999. Modellresulaten jämförs med observationsdata. Temperatur nära ytan och värmeflödet är förhållandevis bra vid en jämförelse med in-situ-mätningar och skattningar baserade på satellitdata. Salthalt och färskvattenutbyte är dock mindre bra. Momentumflödet från atmosfär till hav identifieras som en kritisk process i kopplingen mellan modellerna. Med undantag för färskvattensutbytet mellan atmosfär och hav är de klimatologiska egenskaperna nära ytan och motsvarande flöden jämförbara med klimatologiska observationer för perioden 1970-1999.

  • 3.
    Dieterich, Christian
    et al.
    SMHI, Forskningsavdelningen, Oceanografi.
    Wang, Shiyu
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Schimanke, Semjon
    SMHI, Forskningsavdelningen, Oceanografi.
    Groger, Matthias
    SMHI, Forskningsavdelningen, Oceanografi.
    Klein, Birgit
    Hordoir, Robinson
    SMHI, Forskningsavdelningen, Oceanografi.
    Samuelsson, Patrick
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Liu, Ye
    SMHI, Forskningsavdelningen, Oceanografi.
    Axell, Lars
    SMHI, Forskningsavdelningen, Oceanografi.
    Höglund, Anders
    SMHI, Forskningsavdelningen, Oceanografi.
    Meier, Markus
    SMHI, Forskningsavdelningen, Oceanografi.
    Surface Heat Budget over the North Sea in Climate Change Simulations2019Ingår i: Atmosphere, ISSN 2073-4433, E-ISSN 2073-4433, Vol. 10, nr 5, artikel-id 272Artikel i tidskrift (Refereegranskat)
  • 4.
    Eilola, Kari
    et al.
    SMHI, Forskningsavdelningen, Oceanografi.
    Gustafson, B.G.
    Baltic Nest Institute, Resilience Centre, Stockholm University, Sweden.
    Hordoir, Robinson
    SMHI, Forskningsavdelningen, Oceanografi.
    Höglund, Anders
    SMHI, Forskningsavdelningen, Oceanografi.
    Kuznetsov, I.
    Baltic Sea Research Institute Warnemünde, Germany.
    Meier, Markus
    SMHI, Forskningsavdelningen, Oceanografi.
    Savchuk, O.P.
    Baltic Nest Institute, Resilience Centre, Stockholm University, Sweden.
    Quality assessment of state-of-the-art coupled physical-biogeochemical models in hind cast simulations 1970-20052010Rapport (Övrigt vetenskapligt)
    Abstract [en]

    The objectives of the project ECOSUPPORT (Advanced modeling tool for scenarios of the Baltic Sea ECOsystem to SUPPORT decision making) are to calculate the combined effects of changing climate and changing human activity (e.g. changing nutrient loads) on the Baltic Sea ecosystem. Three state-of-the-art coupled physical-biogeochemical models (BALTSEM, ERGOM, and RCO-SCOBI) are used to calculate changing concentrations of nitrate, ammonium, phosphate, diatoms, flagellates, cyanobacteria, zooplankton, detritus, and oxygen in the Baltic Sea. The models are structurally different in that ERGOM and RCO-SCOBI are 3D circulation models with uniform high horizontal resolution while BALTSEM resolves the Baltic Sea spatially in 13 sub-basins. This report summarises first results of the quality assessment and model intercomparison within ECOSUPPORT. Results from hindcast simulations are compared with observations for the period 1970-2005. We found that all three investigated models are able to reproduce the observed variability of biogeochemical cycles well. Uncertainties are primarily related to differences in the bioavailable fractions of nutrient loadings from land and parameterizations of key processes like sediment fluxes that are presently not well known. Avsikten med projektet ECOSUPPORT (Advanced modeling tool for scenarios of the Baltic Sea ECOsystem to SUPPORT decision making) är att undersöka hur klimatförändringar tillsammans med mänsklig aktivitet (förändrad närsaltstillförsel) påverkar Östersjöns ekosystem. Tre kopplade fysiska-biogeokemiska modeller (BALTSEM, ERGOM, and RCO-SCOBI) används för att beräkna hur koncentrationer av nitrat, ammonium, fosfat, diatoméer, flagellater, cyanobakterier, djurplankton, detritus och löst syrgas i Östersjön förändras. Modellerna skiljer sig strukturellt åt genom att ERGOM och RCO-SCOBI är tredimensionella modeller med hög horisontell upplösning medan BALTSEM delar upp östersjön rumsligt i 13 delbassänger. Denna rapport sammanfattar resultaten från en första modelljämförelse och kvalitetsbedömning där modellresultat för tidsperioden 1970-2005 jämförs med observationer från samma period. Alla tre modellerna visar att de kan återskapa den observerade biogeokemiska variabiliteten väl. Osäkerheter är huvudsakligen relaterade till skillnader i andelen av näringstillförseln från land som antas vara biologiskt tillgänglig och till beskrivningarna av viktiga processer, som t.ex. flöden från sedimenten, där kunskapen för närvarande är bristfällig.

  • 5. Fransner, Filippa
    et al.
    Gustafsson, Erik
    Tedesco, Letizia
    Vichi, Marcello
    Hordoir, Robinson
    SMHI, Forskningsavdelningen, Oceanografi.
    Roquet, Fabien
    Spilling, Kristian
    Kuznetsov, Ivan
    Eilola, Kari
    SMHI, Forskningsavdelningen, Oceanografi.
    Morth, Carl-Magnus
    Humborg, Christoph
    Nycander, Jonas
    Non-Redfieldian Dynamics Explain Seasonal pCO(2) Drawdown in the Gulf of Bothnia2018Ingår i: Journal of Geophysical Research - Oceans, ISSN 2169-9275, E-ISSN 2169-9291, Vol. 123, nr 1, s. 166-188Artikel i tidskrift (Refereegranskat)
  • 6. Fransner, Filippa
    et al.
    Nycander, Jonas
    Morth, Carl-Magnus
    Humborg, Christoph
    Meier, Markus
    SMHI, Forskningsavdelningen, Oceanografi.
    Hordoir, Robinson
    SMHI, Forskningsavdelningen, Oceanografi.
    Gustafsson, Erik
    Deutsch, Barbara
    Tracing terrestrial DOC in the Baltic SeaA 3-D model study2016Ingår i: Global Biogeochemical Cycles, ISSN 0886-6236, E-ISSN 1944-9224, Vol. 30, nr 2, s. 134-148Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The fate of terrestrial organic matter brought to the coastal seas by rivers and its role in the global carbon cycle are still not very well known. Here the degradation rate of terrestrial dissolved organic carbon (DOCter) is studied in the Baltic Sea, a subarctic semienclosed sea, by releasing it as a tracer in a 3-D circulation model and applying linear decay constants. A good agreement with available observational data is obtained by parameterizing the degradation in two rather different ways: one by applying a decay time on the order of 10years to the whole pool of DOCter and one by dividing the DOCter into onerefractory pool and one pool subject to a decay time on the order of 1year. The choice ofparameterization has asignificant effect on where in the Baltic Sea the removal takes place, which can be of importance whenmodeling the full carbon cycle and the CO2 exchange with the atmosphere. In both cases the biogeochemical decayoperates on time scales less than the water residence time. Therefore, only a minor fraction of the DOCter reaches the North Sea, whereas approximately 80% is removed by internal sinks within the Baltic Sea. This further implies that DOCter mineralization is an important link in land-sea-atmosphere cycling of carbon in coastal and shelf seas that are heavily influenced by riverine DOC.

  • 7. Godhe, Anna
    et al.
    Egardt, Jenny
    Kleinhans, David
    Sundqvist, Lisa
    Hordoir, Robinson
    SMHI, Forskningsavdelningen, Oceanografi.
    Jonsson, Per R.
    Seascape analysis reveals regional gene flow patterns among populations of a marine planktonic diatom2013Ingår i: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 280, nr 1773, artikel-id 20131599Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We investigated the gene flow of the common marine diatom, Skeletonema marinoi, in Scandinavian waters and tested the null hypothesis of panmixia. Sediment samples were collected from the Danish Straits, Kattegat and Skagerrak. Individual strains were established from germinated resting stages. A total of 350 individuals were genotyped by eight microsatellite markers. Conventional F-statistics showed significant differentiation between the samples. We therefore investigated whether the genetic structure could be explained using genetic models based on isolation by distance (IBD) or by oceanographic connectivity. Patterns of oceanographic circulation are seasonally dependent and therefore we estimated how well local oceanographic connectivity explains gene flow month by month. We found no significant relationship between genetic differentiation and geographical distance. Instead, the genetic structure of this dominant marine primary producer is best explained by local oceanographic connectivity promoting gene flow in a primarily south to north direction throughout the year. Oceanographic data were consistent with the significant FST values between several pairs of samples. Because even a small amount of genetic exchange prevents the accumulation of genetic differences in F-statistics, we hypothesize that local retention at each sample site, possibly as resting stages, is an important component in explaining the observed genetic structure.

  • 8.
    Hieronymus, Magnus
    et al.
    SMHI, Forskningsavdelningen, Oceanografi.
    Dieterich, Christian
    SMHI, Forskningsavdelningen, Oceanografi.
    Andersson, Helén
    SMHI, Forskningsavdelningen, Oceanografi.
    Hordoir, Robinson
    SMHI, Forskningsavdelningen, Oceanografi.
    The effects of mean sea level rise and strengthened winds on extreme sea levels in the Baltic Sea2018Ingår i: Theoretical and Applied Mechanics Letters, ISSN 2095-0349, Vol. 8, nr 6, s. 366-371Artikel i tidskrift (Refereegranskat)
  • 9.
    Hordoir, Robinson
    et al.
    SMHI, Forskningsavdelningen, Oceanografi.
    An, B.W.
    SMHI.
    Haapala, J.
    SMHI.
    Dieterich, Christian
    SMHI, Forskningsavdelningen, Oceanografi.
    Schimanke, Semjon
    SMHI, Forskningsavdelningen, Oceanografi.
    Höglund, Anders
    SMHI, Forskningsavdelningen, Oceanografi.
    A 3D Ocean Modelling Configuration for Baltic & North Sea Exchange Analysis: BaltiX V 1.12013Rapport (Övrigt vetenskapligt)
    Abstract [en]

    There is a need for having a reliable numerical representation of the exchanges between the Baltic Sea and the North Sea from many points of view. First, the North Sea is the salt provider of the BalticSea, but also the oxygen provider of the lowermost layers of the Baltic Sea. This means that any numerical analysis which has for goal to study the long term changes in this exchange can not rely on a model of the Baltic Sea that has an open boundary condition at the entrance of the Baltic Sea (i.e.: the Kattegat area). In order to represent the long term changes in the exchanges between the NorthSea and the Baltic Sea, one needs to consider the coupling between these two basins which have a very different dynamical behaviour which means one needs to consider them as a whole. This meansthat any regional model should have its open boundary condition further away from the entrance of the Baltic Sea, that is in a place that is remote enough to allow a buffer large enough in the North Sea,so that the SSH variability at the entrance of the Baltic Sea is well represented [7].Second, the Baltic Sea outflow has a great influence on the Norwegian Coastal Current (NCC hereafter) which is also interesting to study, and which can only be well represented if the wind effect over the Baltic Sea is taken into account [9].Many models were successfully applied to the Baltic Sea or/and to the North Sea/Baltic Sea area. On can cite the Rossby Centre Ocean model RCO [15], which successfully represents the thermo-haline as well as the ice structures and variability of the Baltic Sea. One can also cite HIROMB [6], which is a North & Baltic Seas numerical representation used in operational oceanography.However, all these modelling structures lack in at least one of the following points :They include only the Baltic Sea area, which makes impossible the study of the exchanges withthe North Sea.- They were mostly used for operational purpose, and do not have stability properties in terms ofBaltic salt content which does not make them suitable for long term studies.- They do not follow anymore the framework of a community model, and therefore do not benefit of the recent scientific or technical developments implemented in most ocean modelling platform.- A Baltic & North Sea setup is also necessary for long term coupled simulations.There was therefore a need to build a new Baltic & North Sea configuration, based on a community modelling framework, and designed to follow this framework eventually.BaltiX is a Baltic & North Sea configuration based on the NEMO [14] ocean engine. Its development was started in 2011 at SMHI (Swedish Meteorological & Hydrological Institute, Norrköping, Sweden). It follows closely the development of the NEMO ocean engine, and BaltiX is updated each time an update is done in it.In the present report, Section 2 describes the configuration and explains the choices that have been made to build it. Based on a simulation done for the period 1961-2007, we then present several results. Section 3 presents a barotropic analysis of the results provided by the configuration, and Section 4 presents results in terms of salinity and temperature variability. Section 5 has been specifically written to present the sea-ice model coupled to BaltiX and its effects in terms of sea-ice variability. A last part provides a short conclusion to the present report.

  • 10.
    Hordoir, Robinson
    et al.
    SMHI, Forskningsavdelningen, Oceanografi.
    Axell, Lars
    SMHI, Forskningsavdelningen, Oceanografi.
    Höglund, Anders
    SMHI, Forskningsavdelningen, Oceanografi.
    Dieterich, Christian
    SMHI, Forskningsavdelningen, Oceanografi.
    Fransner, Filippa
    Groger, Matthias
    SMHI, Forskningsavdelningen, Oceanografi.
    Liu, Ye
    SMHI, Forskningsavdelningen, Oceanografi.
    Pemberton, Per
    SMHI, Forskningsavdelningen, Oceanografi.
    Schimanke, Semjon
    SMHI, Forskningsavdelningen, Oceanografi.
    Andersson, Helén
    SMHI, Forskningsavdelningen, Oceanografi.
    Ljungemyr, Patrik
    SMHI, Samhälle och säkerhet.
    Nygren, Petter
    SMHI, Samhälle och säkerhet.
    Falahat, Saeed
    SMHI, Samhälle och säkerhet.
    Nord, Adam
    SMHI, Samhälle och säkerhet.
    Jönsson, Anette
    SMHI, Samhälle och säkerhet.
    Lake, Irene
    SMHI, Samhälle och säkerhet. SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Doos, Kristofer
    Hieronymus, Magnus
    SMHI, Forskningsavdelningen, Oceanografi.
    Dietze, Heiner
    Loeptien, Ulrike
    Kuznetsov, Ivan
    Westerlund, Antti
    Tuomi, Laura
    Haapala, Jari
    Nemo-Nordic 1.0: a NEMO-based ocean model for the Baltic and North seas - research and operational applications2019Ingår i: Geoscientific Model Development, ISSN 1991-959X, E-ISSN 1991-9603, Vol. 12, nr 1, s. 363-386Artikel i tidskrift (Refereegranskat)
  • 11.
    Hordoir, Robinson
    et al.
    SMHI, Forskningsavdelningen, Oceanografi.
    Axell, Lars
    SMHI, Forskningsavdelningen, Oceanografi.
    Löptien, Ulrike
    SMHI, Forskningsavdelningen, Oceanografi.
    Dietze, Heiner
    Kuznetsov, Ivan
    SMHI, Forskningsavdelningen, Oceanografi.
    Influence of sea level rise on the dynamics of salt inflows in the Baltic Sea2015Ingår i: Journal of Geophysical Research - Oceans, ISSN 2169-9275, E-ISSN 2169-9291, Vol. 120, nr 10, s. 6653-6668Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Baltic Sea is a marginal sea, located in a highly industrialized region in Central Northern Europe. Saltwater inflows from the North Sea and associated ventilation of the deep exert crucial control on the entire Baltic Sea ecosystem. This study explores the impact of anticipated sea level changes on the dynamics of those inflows. We use a numerical oceanic general circulation model covering both the Baltic and the North Sea. The model successfully retraces the essential ventilation dynamics throughout the period 1961-2007. A suite of idealized experiments suggests that rising sea level is associated with intensified ventilation as saltwater inflows become stronger, longer, and more frequent. Expressed quantitatively as a salinity increase in the deep central Baltic Sea, we find that a sea level rise of 1 m triggers a saltening of more than 1 PSU. This substantial increase in ventilation is the consequence of the increasing cross section in the Danish Straits amplified by a reduction of vertical mixing.

  • 12.
    Hordoir, Robinson
    et al.
    SMHI, Forskningsavdelningen, Oceanografi.
    Dieterich, Christian
    SMHI, Forskningsavdelningen, Oceanografi.
    Basu, Chandan
    Dietze, Heiner
    Meier, Markus
    SMHI, Forskningsavdelningen, Oceanografi.
    Freshwater outflow of the Baltic Sea and transport in the Norwegian current: A statistical correlation analysis based on a numerical experiment2013Ingår i: Continental Shelf Research, ISSN 0278-4343, E-ISSN 1873-6955, Vol. 64, s. 1-9Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Based on the results of a numerical ocean model, we investigate statistical correlations between wind forcing, surface salinity and freshwater transport out of the Baltic Sea on one hand, and Norwegian coastal current freshwater transport on the other hand. These correlations can be explained in terms of physics and reveal how the two freshwater transports are linked with wind forcing, although this information proves to be non-sufficient when it comes to the dynamics of the Norwegian coastal current. Based on statistical correlations, the Baltic Sea freshwater transport signal is reconstructed and shows a good correlation but a poor variability when compared with the measured signal, at least when data filtered on a two-daily time scale is used. A better variability coherence is reached when data filtered on a weekly or monthly time scale is used. In the latest case, a high degree of precision is reached for the reconstructed signal. Using the same kind of methods for the case of the Norwegian coastal current, the negative peaks of the freshwater transport signal can be reconstructed based on wind data only, but the positive peaks are under-represented although some of them exist mostly because the meridional wind forcing along the Norwegian coast is taken into account. Adding Norwegian coastal salinity data helps improving the reconstruction of the positive peaks, but a major improvement is reached when adding non-linear terms in the statistical reconstruction. All coefficients used to re-construct both freshwater transport signals are provided for use in European Shelf or climate modeling configurations. (c) 2013 Elsevier Ltd. All rights reserved.

  • 13.
    Hordoir, Robinson
    et al.
    SMHI, Forskningsavdelningen, Oceanografi.
    Höglund, Anders
    SMHI, Forskningsavdelningen, Oceanografi.
    Pemberton, Per
    SMHI, Forskningsavdelningen, Oceanografi.
    Schimanke, Semjon
    SMHI, Forskningsavdelningen, Oceanografi.
    Sensitivity of the overturning circulation of the Baltic Sea to climate change, a numerical experiment2018Ingår i: Climate Dynamics, ISSN 0930-7575, E-ISSN 1432-0894, Vol. 50, nr 3-4, s. 1425-1437Artikel i tidskrift (Refereegranskat)
  • 14.
    Hordoir, Robinson
    et al.
    SMHI, Forskningsavdelningen, Oceanografi.
    Meier, Markus
    SMHI, Forskningsavdelningen, Oceanografi.
    Effect of climate change on the thermal stratification of the baltic sea: a sensitivity experiment2012Ingår i: Climate Dynamics, ISSN 0930-7575, E-ISSN 1432-0894, Vol. 38, nr 9-10, s. 1703-1713Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The evolution in time of the thermal vertical stratification of the Baltic Sea in future climate is studied using a 3D ocean model. Comparing periods at the end of the twentieth and twenty first centuries we found a strong increase in stratification at the bottom of the mixed layer in the northern Baltic Sea. In order to understand the causes of this increase, a sensitivity analysis is performed. We found that the increased vertical stratification is explained by a major change in re-stratification during spring solely caused by the increase of the mean temperature. As in present climate winter temperatures in the Baltic are often below the temperature of maximum density, warming causes thermal convection. Re-stratification during the beginning of spring is then triggered by the spreading of freshwater. This process is believed to be important for the onset of the spring bloom. In future climate, temperatures are expected to be usually higher than the temperature of maximum density and thermally induced stratification will start without prior thermal convection. Thus, freshwater controlled re-stratification during spring is not an important process anymore. We employed a simple box model and used sensitivity experiments with the 3D ocean model to delineate the processes involved and to quantify the impact of changing freshwater supply on the thermal stratification in the Baltic Sea. It is suggested that these stratification changes may have an important impact on vertical nutrient fluxes and the intensity of the spring bloom in future climate of the Baltic Sea.

  • 15.
    Hordoir, Robinson
    et al.
    SMHI, Forskningsavdelningen, Oceanografi.
    Meier, Markus
    SMHI, Forskningsavdelningen, Oceanografi.
    Freshwater fluxes in the Baltic Sea: A model study2010Ingår i: Journal of Geophysical Research, ISSN 0148-0227, E-ISSN 2156-2202, Vol. 115, artikel-id C08028Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The dynamics of "juvenile" freshwater, which is released during spring into the Baltic proper, is studied using a numerical three-dimensional circulation model. Two methods are used. First, freshwater heights are calculated using simulated salinity fields, and their seasonal variability is analyzed. When compared to climatological observations, the model represents the seasonal variability of freshwater heights well. However, the method does not allow a proper study of the dynamics of juvenile freshwater fluxes. Consequently, a second method is used where a passive tracer, which marks freshwater, is utilized. This method provides a better description of the seasonal spreading of juvenile freshwater in the Baltic proper, although further investigations are still necessary to trace juvenile freshwater. The results from this second method show that juvenile freshwater does not reach the center of the Baltic proper before late summer. During one season, only a small amount of juvenile freshwater may reach the entrance of the Baltic Sea. The increased vertical stratification generated by the arrival of juvenile freshwater and the subsequent baroclinic adjustment may trigger the onset of the spring bloom in accordance to earlier suggestions. Further, the seasonal cycle and inter-annual variability of the freshwater outflow from the Baltic Sea are studied. Seasonal changes of the freshwater outflow are closely connected with that of the zonal wind, although the annual mean outflow is given by the total runoff into the Baltic Sea. Thus, the inter-annual variability of the seasonal freshwater outflow maximum is highly correlated with the North Atlantic Oscillation.

  • 16.
    Höglund, Anders
    et al.
    SMHI, Forskningsavdelningen, Oceanografi.
    Pemberton, Per
    SMHI, Forskningsavdelningen, Oceanografi.
    Hordoir, Robinson
    SMHI, Forskningsavdelningen, Oceanografi.
    Schimanke, Semjon
    SMHI, Forskningsavdelningen, Oceanografi.
    Ice conditions for maritime traffic in the Baltic Sea in future climate2017Ingår i: Boreal environment research, ISSN 1239-6095, E-ISSN 1797-2469, Vol. 22, s. 245-265Artikel i tidskrift (Refereegranskat)
  • 17.
    Kuznetsov, Ivan
    et al.
    SMHI, Forskningsavdelningen, Oceanografi.
    Eilola, Kari
    SMHI, Forskningsavdelningen, Oceanografi.
    Dieterich, Christian
    SMHI, Forskningsavdelningen, Oceanografi.
    Hordoir, Robinson
    SMHI, Forskningsavdelningen, Oceanografi.
    Axell, Lars
    SMHI, Forskningsavdelningen, Oceanografi.
    Höglund, Anders
    SMHI, Forskningsavdelningen, Oceanografi.
    Schimanke, Semjon
    SMHI, Forskningsavdelningen, Oceanografi.
    Model study on the variability of ecosystem parameters in the Skagerrak-Kattegat area, effect of load reduction in the North Sea and possible effect of BSAP on Skagerrak-Kattegat area2016Rapport (Övrigt vetenskapligt)
    Abstract [sv]

    Den nyligen utvecklade ekosystemmodellen NEMO-Nordic-SCOBI användes för att studera variabiliteten av några indikatorer för ekosystemet i Skagerrak- kattegatt området. Även två känslighetsstudier gjordes för att undersöka möjliga effekter av Baltic Sea Action Plan (BSAP) och en reduktion scenario av närsaltstillförsel på Skagerrak-Kattegatt området. Den utförda studien kan användas som underlag och stöd vid tolkningen av observationsdata inför utvärderingen ”Intermediate Assessments Eutrophication status assessment”. Jämförelsen mellan modelldata och observationer indikerar att modellens resultat är acceptabla. Modellerade ytvärden av salthalt, temperatur och löst fosfat (DIP) visar god överenskommelse med observerade värden. Samtidigt har modellresultaten avvikelser i vissa delområden vad gäller löst oorganiskt kväve (DIN) och löst kisel under vitertid. Dock visar modellen i sitt nuvarande tillstånd tillräckligt goda resultat för den aktuella studien. Resultaten från de två känslighetsstudierna visar en minskning av näringskoncentrationer i ytan under vintern i båda havsområdena. I Skagerrak är minskningen orsakad av reducerad närsaltstillförsel i Nordsjön. I Kattegatt minskar lösta fosfatet på grund av genomförandet av BSAP. Ingen av scenarierna visade någon signifikant påverkan på syre vid havsbotten eller på ytkoncentratiner av Chl-a.

  • 18.
    Meier, Markus
    et al.
    SMHI, Forskningsavdelningen, Oceanografi.
    Hordoir, Robinson
    SMHI, Forskningsavdelningen, Oceanografi.
    Andersson, Helén
    SMHI, Forskningsavdelningen, Oceanografi.
    Dieterich, Christian
    SMHI, Forskningsavdelningen, Oceanografi.
    Eilola, Kari
    SMHI, Forskningsavdelningen, Oceanografi.
    Gustafsson, B. G.
    Höglund, Anders
    SMHI, Forskningsavdelningen, Oceanografi.
    Schimanke, Semjon
    SMHI, Forskningsavdelningen, Oceanografi.
    Modeling the combined impact of changing climate and changing nutrient loads on the Baltic Sea environment in an ensemble of transient simulations for 1961-20992012Ingår i: Climate Dynamics, ISSN 0930-7575, E-ISSN 1432-0894, Vol. 39, nr 9-10, s. 2421-2441Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The combined future impacts of climate change and industrial and agricultural practices in the Baltic Sea catchment on the Baltic Sea ecosystem were assessed. For this purpose 16 transient simulations for 1961-2099 using a coupled physical-biogeochemical model of the Baltic Sea were performed. Four climate scenarios were combined with four nutrient load scenarios ranging from a pessimistic business-as-usual to a more optimistic case following the Baltic Sea Action Plan (BSAP). Annual and seasonal mean changes of climate parameters and ecological quality indicators describing the environmental status of the Baltic Sea like bottom oxygen, nutrient and phytoplankton concentrations and Secchi depths were studied. Assuming present-day nutrient concentrations in the rivers, nutrient loads from land increase during the twenty first century in all investigated scenario simulations due to increased volume flows caused by increased net precipitation in the Baltic catchment area. In addition, remineralization rates increase due to increased water temperatures causing enhanced nutrient flows from the sediments. Cause-and-effect studies suggest that both processes may play an important role for the biogeochemistry of eutrophicated seas in future climate partly counteracting nutrient load reduction efforts like the BSAP.

  • 19.
    Meier, Markus
    et al.
    SMHI, Forskningsavdelningen, Oceanografi.
    Muller-Karulis, Barbel
    Andersson, Helén
    SMHI, Forskningsavdelningen, Oceanografi.
    Dieterich, Christian
    SMHI, Forskningsavdelningen, Oceanografi.
    Eilola, Kari
    SMHI, Forskningsavdelningen, Oceanografi.
    Gustafsson, Bo G.
    Höglund, Anders
    SMHI, Forskningsavdelningen, Oceanografi.
    Hordoir, Robinson
    SMHI, Forskningsavdelningen, Oceanografi.
    Kuznetsov, Ivan
    SMHI, Forskningsavdelningen, Oceanografi.
    Neumann, Thomas
    Ranjbar, Zohreh
    Savchuk, Oleg P.
    Schimanke, Semjon
    SMHI, Forskningsavdelningen, Oceanografi.
    Impact of Climate Change on Ecological Quality Indicators and Biogeochemical Fluxes in the Baltic Sea: A Multi-Model Ensemble Study2012Ingår i: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 41, nr 6, s. 558-573Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Multi-model ensemble simulations using three coupled physical-biogeochemical models were performed to calculate the combined impact of projected future climate change and plausible nutrient load changes on biogeochemical cycles in the Baltic Sea. Climate projections for 1961-2099 were combined with four nutrient load scenarios ranging from a pessimistic business-as-usual to a more optimistic case following the Helsinki Commission's (HELCOM) Baltic Sea Action Plan (BSAP). The model results suggest that in a future climate, water quality, characterized by ecological quality indicators like winter nutrient, summer bottom oxygen, and annual mean phytoplankton concentrations as well as annual mean Secchi depth (water transparency), will be deteriorated compared to present conditions. In case of nutrient load reductions required by the BSAP, water quality is only slightly improved. Based on the analysis of biogeochemical fluxes, we find that in warmer and more anoxic waters, internal feedbacks could be reinforced. Increased phosphorus fluxes out of the sediments, reduced denitrification efficiency and increased nitrogen fixation may partly counteract nutrient load abatement strategies.

  • 20. Moksnes, Per-Olav
    et al.
    Corell, Hanna
    Tryman, Kentaroo
    Hordoir, Robinson
    SMHI, Forskningsavdelningen, Oceanografi.
    Jonsson, Per R.
    Larval behavior and dispersal mechanisms in shore crab larvae (Carcinus maenas): Local adaptations to different tidal environments?2014Ingår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 59, nr 2, s. 588-602Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Using a combination of empirical and model studies we tested whether European shore crab larvae (Carcinus maenas) from environments with different tidal regimes in the North Sea area have different swimming behaviors, and whether this affects connectivity and settlement success of larvae. Laboratory studies demonstrated the presence of an inherited tidal migration rhythm in newly hatched crab larvae from the mesotidal Danish Wadden Sea, and field studies showed that postlarvae swam in surface water almost exclusively during flood tides, suggesting that larvae use selective tidal stream transport to control the dispersal process. In contrast, shore crab larvae from microtidal Skagerrak displayed a nocturnal vertical migration behavior that appeared to switch to a diurnal behavior at the end of the postlarval phase, indicating an adaptation to avoid visual predators and to use wind-driven transport to reach shallow settlement areas. A biophysical model showed that tidal-migrating larvae in the Wadden Sea had two times higher settlement success than larvae with a diel behavior. However, no differences in settlement success were found between the two larval behaviors in microtidal Skagerrak, where lower fitness is suggested for tidal-migrating larvae due to higher predation mortality from visual predators. We suggest that the differences in inherited larval behavior in larvae from meso-and microtidal regions reflect local adaptations maintained through natural selection of successful recruits. Consistent with recent population genetic studies, modeled connectivity of shore crabs indicated an oceanographic dispersal barrier to gene flow in Eastern Wadden Sea that may facilitate such adaptations.

  • 21.
    Pemberton, Per
    et al.
    SMHI, Forskningsavdelningen, Oceanografi.
    Löptien, Ulrike
    SMHI, Forskningsavdelningen, Oceanografi.
    Hordoir, Robinson
    SMHI, Forskningsavdelningen, Oceanografi.
    Höglund, Anders
    SMHI, Forskningsavdelningen, Oceanografi.
    Schimanke, Semjon
    SMHI, Forskningsavdelningen, Oceanografi.
    Axell, Lars
    SMHI, Forskningsavdelningen, Oceanografi.
    Haapala, Jari
    Sea-ice evaluation of NEMO-Nordic 1.0: a NEMO-LIM3.6-based ocean-sea-ice model setup for the North Sea and Baltic Sea2017Ingår i: Geoscientific Model Development, ISSN 1991-959X, E-ISSN 1991-9603, Vol. 10, nr 8, s. 3105-3123Artikel i tidskrift (Refereegranskat)
  • 22.
    Saraiva, Sofia
    et al.
    SMHI, Forskningsavdelningen, Oceanografi.
    Meier, Markus
    SMHI, Forskningsavdelningen, Oceanografi.
    Andersson, Helén
    SMHI, Forskningsavdelningen, Oceanografi.
    Höglund, Anders
    SMHI, Forskningsavdelningen, Oceanografi.
    Dieterich, Christian
    SMHI, Forskningsavdelningen, Oceanografi.
    Groger, Matthias
    SMHI, Forskningsavdelningen, Oceanografi.
    Hordoir, Robinson
    SMHI, Forskningsavdelningen, Oceanografi.
    Eilola, Kari
    SMHI, Forskningsavdelningen, Oceanografi.
    Baltic Sea ecosystem response to various nutrient load scenarios in present and future climates2019Ingår i: Climate Dynamics, ISSN 0930-7575, E-ISSN 1432-0894, Vol. 52, nr 5-6, s. 3369-3387Artikel i tidskrift (Refereegranskat)
  • 23.
    Saraiva, Sofia
    et al.
    SMHI, Forskningsavdelningen, Oceanografi.
    Meier, Markus
    SMHI, Forskningsavdelningen, Oceanografi.
    Andersson, Helén
    SMHI, Forskningsavdelningen, Oceanografi.
    Höglund, Anders
    SMHI, Forskningsavdelningen, Oceanografi.
    Dieterich, Christian
    SMHI, Forskningsavdelningen, Oceanografi.
    Groger, Matthias
    SMHI, Forskningsavdelningen, Oceanografi.
    Hordoir, Robinson
    SMHI, Forskningsavdelningen, Oceanografi.
    Eilola, Kari
    SMHI, Forskningsavdelningen, Oceanografi.
    Uncertainties in Projections of the Baltic Sea Ecosystem Driven by an Ensemble of Global Climate Models2019Ingår i: FRONTIERS IN EARTH SCIENCE, ISSN 2296-6463, Vol. 6, artikel-id UNSP 244Artikel i tidskrift (Refereegranskat)
  • 24.
    Schimanke, Semjon
    et al.
    SMHI, Forskningsavdelningen, Oceanografi.
    Meier, Markus
    SMHI, Forskningsavdelningen, Oceanografi.
    Kjellström, Erik
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Strandberg, Gustav
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Hordoir, Robinson
    SMHI, Forskningsavdelningen, Oceanografi.
    The climate in the Baltic Sea region during the last millennium simulated with a regional climate model2012Ingår i: Climate of the Past, ISSN 1814-9324, E-ISSN 1814-9332, Vol. 8, nr 5, s. 1419-1433Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Variability and long-term climate change in the Baltic Sea region is investigated for the pre-industrial period of the last millennium. For the first time dynamical down-scaling covering the complete millennium is conducted with a regional climate model in this area. As a result of changing external forcing conditions, the model simulation shows warm conditions in the first centuries followed by a gradual cooling until ca. 1700 before temperature increases in the last centuries. This long-term evolution, with a Medieval Climate Anomaly (MCA) and a Little Ice Age (LIA), is in broad agreement with proxy-based reconstructions. However, the timing of warm and cold events is not captured at all times. We show that the regional response to the global climate anomalies is to a strong degree modified by the large-scale circulation in the model. In particular, we find that a positive phase of the North Atlantic Oscillation (NAO) simulated during MCA contributes to enhancing winter temperatures and precipitation in the region while a negative NAO index in the LIA reduces them. In a second step, the regional ocean model (RCO-SCOBI) is used to investigate the impact of atmospheric changes onto the Baltic Sea for two 100 yr time slices representing the MCA and the LIA. Besides the warming of the Baltic Sea, the water becomes fresher at all levels during the MCA. This is induced by increased runoff and stronger westerly winds. Moreover, the oxygen concentrations in the deep layers are slightly reduced during the MCA. Additional sensitivity studies are conducted to investigate the impact of even higher temperatures and increased nutrient loads. The presented experiments suggest that changing nutrient loads may be more important determining oxygen depletion than changes in temperature or dynamic feedbacks.

  • 25. Tuomi, Laura
    et al.
    Kanarik, Hedi
    Bjorkqvist, Jan-Victor
    Marjamaa, Riikka
    Vainio, Jouni
    Hordoir, Robinson
    SMHI, Forskningsavdelningen, Oceanografi.
    Höglund, Anders
    SMHI, Forskningsavdelningen, Oceanografi.
    Kahma, Kimmo K.
    Impact of Ice Data Quality and Treatment on Wave Hindcast Statistics in Seasonally Ice-Covered Seas2019Ingår i: Frontiers in Earth Science, ISSN 2296-6463, Vol. 7, artikel-id UNSP 166Artikel i tidskrift (Refereegranskat)
  • 26.
    Wang, Shiyu
    et al.
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Dieterich, Christian
    SMHI, Forskningsavdelningen, Oceanografi.
    Doescher, Ralf
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Höglund, Anders
    SMHI, Forskningsavdelningen, Oceanografi.
    Hordoir, Robinson
    SMHI, Forskningsavdelningen, Oceanografi.
    Meier, Markus
    SMHI, Forskningsavdelningen, Oceanografi.
    Samuelsson, Patrick
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Schimanke, Semjon
    SMHI, Forskningsavdelningen, Oceanografi.
    Development and evaluation of a new regional coupled atmosphere-ocean model in the North Sea and Baltic Sea2015Ingår i: Tellus. Series A, Dynamic meteorology and oceanography, ISSN 0280-6495, E-ISSN 1600-0870, Vol. 67, artikel-id 24284Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A new regional coupled model system for the North Sea and the Baltic Sea is developed, which is composed of the regional setup of ocean model NEMO, the Rossby Centre regional climate model RCA4, the sea ice model LIM3 and the river routing model CaMa-Flood. The performance of this coupled model system is assessed using a simulation forced with ERA-Interim reanalysis data at the lateral boundaries during the period 1979-2010. Compared to observations, this coupled model system can realistically simulate the present climate. Since the active coupling area covers the North Sea and Baltic Sea only, the impact of the ocean on the atmosphere over Europe is small. However, we found some local, statistically significant impacts on surface parameters like 2m air temperature and sea surface temperature (SST). A precipitation-SST correlation analysis indicates that both coupled and uncoupled models can reproduce the air-sea relationship reasonably well. However, the coupled simulation gives slightly better correlations even when all seasons are taken into account. The seasonal correlation analysis shows that the air-sea interaction has a strong seasonal dependence. Strongest discrepancies between the coupled and the uncoupled simulations occur during summer. Due to lack of air-sea interaction, in the Baltic Sea in the uncoupled atmosphere-standalone run the correlation between precipitation and SST is too small compared to observations, whereas the coupled run is more realistic. Further, the correlation analysis between heat flux components and SST tendency suggests that the coupled model has a stronger correlation. Our analyses show that this coupled model system is stable and suitable for different climate change studies.

1 - 26 av 26
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