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  • 251.
    Fonselius, Stig
    et al.
    SMHI, Forskningsavdelningen, Oceanografi.
    Valderrama, Jorge
    SMHI, Forskningsavdelningen, Oceanografi.
    One hundred years of hydrographic measurements in the Baltic Sea2003Ingår i: Journal of Sea Research, ISSN 1385-1101, E-ISSN 1873-1414, Vol. 49, nr 4, s. 229-241Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The first measurements of salinity of the deep water in the open Baltic Sea were made in the last decades of the 1800s. At a Scandinavian science meeting in Copenhagen in 1892, Professor Otto Pettersson from Sweden suggested that regular measurements of hydrographic parameters should be carried out at some important deep stations in the Baltic Sea. His suggestion was adopted and since that time we have rather complete hydrographical data from the Bornholm Deep, the Gotland Deep, and the Landsort Deep and from some stations in the Gulf of Bothnia. The measurements were interrupted in the Baltic Proper during the two World Wars. At the beginning only salinity, temperature and dissolved oxygen were measured and one or two expeditions were carried out annually, mostly in summer. In the 1920s also alkalinity and pH were occasionally measured and total carbonate was calculated. A few nutrient measurements were also carried out. After World War 11 we find results from four or more expeditions every year and intercalibration of methods was arranged. Results of temperature, salinity and dissolved oxygen measurements from the Bornholm. Deep, the Gotland Deep, the Landsort Deep and salinity measurements from three stations in the Gulf of Bothnia, covering the whole 20th century are presented and discussed. The salinity distribution and the variations between oxygen and hydrogen sulphide periods in the deep water of the Gotland Deep and the Landsort Deep are demonstrated. Series of phosphate and nitrate distribution in the Gotland Deep are shown from the 1950s to the present and the effects of the stagnant conditions are briefly discussed. Two large inflows of highly saline water, the first during the First World War and the second in 195 1, are demonstrated. The 20th century minimum salinity of the bottom water in the Baltic Proper in 1992 is discussed. (C) 2003 Published by Elsevier Science B.V.

  • 252. Fosser, G.
    et al.
    Khodayar, S.
    Berg, Peter
    SMHI, Forskningsavdelningen, Hydrologi.
    Benefit of convection permitting climate model simulations in the representation of convective precipitation2015Ingår i: Climate Dynamics, ISSN 0930-7575, E-ISSN 1432-0894, Vol. 44, nr 1-2, s. 45-60Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A major source of uncertainty in regional climate model (RCM) simulations arises from the parameterisation of sub-grid scale convection. With increasing model resolution, approaching the so-called convection permitting scale, it is possible to switch off most of the convection parameterisations. A set of simulations using COSMO-CLM model has been carried out at different resolutions in order to investigate possible improvements and limitations resulting from increased horizontal resolution. For our analysis, 30 years were simulated in a triple nesting setup with 50, 7 and 2.8 km resolutions, with ERA40 reanalysis data at the lateral boundaries of the coarsest nest. The investigation area covers the state of Baden-Wurttemberg in southwestern Germany, which is a region known for abundant orographically induced convective precipitation. A very dense network of high temporal resolution rain gauges is used for evaluation of the model simulations. The purpose of this study is to examine the differences between the 7 and 2.8 km resolutions in the representation of precipitation at sub-daily timescales, and the atmospheric conditions leading to convection. Our results show that the highest resolution of RCM simulations significantly improves the representation of both hourly intensity distribution and diurnal cycle of precipitation. In addition, at convection permitting scale the atmospheric fields related to convective precipitation show a better agreement with each other. The results imply that higher spatial resolution partially improves the representation of the precipitation field, which must be the way forward for regional climate modelling.

  • 253. Fosser, G.
    et al.
    Khodayar, S.
    Berg, Peter
    SMHI, Forskningsavdelningen, Hydrologi.
    Climate change in the next 30 years: What can a convection-permitting model tell us that we did not already know?2017Ingår i: Climate Dynamics, ISSN 0930-7575, E-ISSN 1432-0894, Vol. 48, nr 5-6, s. 1987-2003Artikel i tidskrift (Refereegranskat)
  • 254.
    Foster, Kean
    et al.
    SMHI, Forskningsavdelningen, Hydrologi.
    Uvo, Cintia Bertacchi
    Olsson, Jonas
    SMHI, Forskningsavdelningen, Hydrologi.
    The development and evaluation of a hydrological seasonal forecast system prototype for predicting spring flood volumes in Swedish rivers2018Ingår i: Hydrology and Earth System Sciences, ISSN 1027-5606, E-ISSN 1607-7938, Vol. 22, nr 5, s. 2953-2970Artikel i tidskrift (Refereegranskat)
  • 255. 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)
  • 256. 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.

  • 257.
    Fransson, L.
    et al.
    SMHI.
    Håkansson, Bertil
    SMHI, Forskningsavdelningen, Oceanografi.
    Omstedt, Anders
    SMHI, Forskningsavdelningen, Oceanografi.
    Stehn, L.
    SMHI.
    Sea ice properties studied from the ice-breaker Tor during BEPERS-881989Rapport (Övrigt vetenskapligt)
  • 258. Froberg, Mats
    et al.
    Hansson, Karna
    Kleja, Dan Berggren
    Alavi, Ghasem
    SMHI, Affärsverksamhet.
    Dissolved organic carbon and nitrogen leaching from Scots pine, Norway spruce and silver birch stands in southern Sweden2011Ingår i: Forest Ecology and Management, ISSN 0378-1127, E-ISSN 1872-7042, Vol. 262, nr 9, s. 1742-1747Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The effects of three common tree species - Scots pine, Norway spruce and silver birch - on leaching of dissolved organic carbon and dissolved nitrogen were studied in an experimental forest with podzolised soils in southern Sweden. We analyzed soil water collected with lysimeters and modeled water fluxes to estimate dissolved C and N fluxes. Specific UV absorbance (SUVA) was analyzed to get information about the quality of dissolved organic matter leached from the different stands. Under the O horizon, DOC concentrations and fluxes in the birch stands were lower than in the spruce and pine stands; annual fluxes were 21 g m(-2) y(-1) for birch and 38 g m(-2) y(-1) and 37 g C m(-2) y(-1) for spruce and pine, respectively. Under the B horizon, annual fluxes for all tree species ranged between 3 and 5 g C m(-2) y(-1), implying greater loss of DOC in the mineral soil in the coniferous stands than in the birch stands. We did not find any effect of tree species on the quality of the dissolved organic matter, as measured by SUVA, indicating that the chemical composition of the organic matter was similar in leachates from all three tree species. Substantial amounts of nitrogen was leached out of the soil profile at the bottom of the B horizon from the pine and birch stands, whereas the spruce stands seemed to retain most of the nitrogen in the soil. These differences in N leaching have implications for soil N budgets. (C) 2011 Elsevier B.V. All rights reserved.

  • 259.
    Funquist, Lennart
    SMHI, Forskningsavdelningen, Oceanografi.
    En hydrodynamisk modell för spridnings- och cirkulationsberäkningar i Östersjön: Slutrapport1985Rapport (Övrigt vetenskapligt)
    Abstract [sv]
    • En modell för beräkning av föroreningars spridning i Östersjön har utvecklats vid SMHI
    • Modellen behandlar spridning såväl horisontellt som vertikal och kan användas för spridningsstudier i en tidsskala från timmar till år.
    • Biokemiska förlopp kan utan svårighet inkluderas 1 modellen.
    • Modellen är ett lämpligt redskap för studier av pågående utsläpp, katastrofutsläpp och i samband med industrilokalisering.
    • Kustområden med återkommande uppvällning kan identifieras med hjälp av modellen.
    • Cirkulationsmodellen ger ett värdefullt bidrag till den allmänna kunskapen om Östersjöns dynamik.
  • 260.
    Funquist, Lennart
    SMHI, Forskningsavdelningen, Oceanografi.
    Numerisk beräkning av vågor i kraftverksdammar1987Rapport (Övrigt vetenskapligt)
    Abstract [sv]

    Kraftiga vågrörelser uppstår i kraftverksmagasin,  när avtappningen hastigt stryps. Detta kan vara fallet vid störningar i kraftverksdriften eller eldistributionsnätet.Om vattennivån i magasinet ligger nära dämningsgränsen, kan vågorna orsaka störningar i ytregleringsautomatiken och katastrofskyddet, samtidigt som dämningsgränsen kan överskridas. Liknande problem kan uppstå i korttidsreglerade magasin.Amplituder på upp till o.60 m har registrerats just vid utloppet (Stugun), medan längre uppströms endast registreras vågor med en amplitud mindre än 0.15 m. Initialt bildas vågor av flera frekvenser, och de högfrekventa och med högst  amplitud dämpas mycket kraftigt och försvinner efter 100 - 200 m. Vattenståndshöjningen, som orsakas av det plötsliga stoppet, är emellertid synlig i hela magasinet som en solitär våg med en amplitud av upp till 0.20 m. Dessutom uppstår egensvängningar i delbassänger nära utloppet med en amlitud på 0.05 - 0.15 m, vilket kan vara nog för att i vissa fall överskrida dämningsgränsen.Avsikten med den här redovisade studien är att utröna huruvida uppmätta vågor går att reproducera i en numerisk modell, och vidare om modellen kan tillämpas på godtyckligt magasin för studier av effekten av dessa vågor.

  • 261.
    Funquist, Lennart
    et al.
    SMHI, Forskningsavdelningen, Oceanografi.
    Gidhagen, Lars
    SMHI, Forskningsavdelningen, Luftmiljö.
    Svensson, Urban
    SMHI, Forskningsavdelningen, Oceanografi.
    THE MATHEMATICAL-MODELING OF BAROCLINIC WAVES AND FRONTS IN THE OCEAN1987Ingår i: Applied Mathematical Modelling, ISSN 0307-904X, E-ISSN 1872-8480, Vol. 11, nr 1, s. 11-18Artikel i tidskrift (Refereegranskat)
  • 262.
    Funquist, Lennart
    et al.
    SMHI, Forskningsavdelningen, Oceanografi.
    Ljungemyr, Patrik
    SMHI, Samhälle och säkerhet.
    Validation of HIROMB during 1995-961997Rapport (Övrigt vetenskapligt)
    Abstract [en]

    IROMB (High Resolution Operational Model of the Baltic Sea) is the result of a combined effort between BSH (Bundesamt för Seeschiffahrt und Hydrographie) and SMHI (Swedish Meteorological and Hydrological Institute). In its present form, the model is a modified version of the BSH operational model (Kleine, 1994) with identical boundaries to the North Atlantic. The cooperation started in summer 1994 when the model was set up at SMHI. The first operational runs started in the sumrner 1995 and since then the model has been running daily except fora limited number of periods when there were no meteorological input from the HIRLAM (atmospheric) model available because of computer problems. During the first months, some occasions with stability problems occurred, leading toa restart from the climatological fields.

    This report presents results from a continous verification exercise, where model results are compared to observations of water level, surface temperature, currents, ice thickness and salinity and temperature profiles. The times series data are taken from the period September-November 1996 while the ice thickness data are from November and December 1996 and the sea surface temperature data are taken from August, November and December 1996.

    For a detailed description of the model, the reader is referred to a forthcoming report by Funkquist and Kleine.

  • 263.
    Gardelin, Marie
    et al.
    SMHI, Affärsverksamhet.
    Lindström, Göran
    SMHI, Forskningsavdelningen, Hydrologi.
    Priestley-Taylor evapotranspiration in HBV-simulations1997Ingår i: Nordic Hydrology, ISSN 0029-1277, E-ISSN 1996-9694, Vol. 28, nr 4-5, s. 233-246Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Estimations of potential evapotranspiration as input to runoff calculations with the HBV model are usually given as monthly standard values calculated with the Penman method. Daily changes in the weather conditions can in later model versions be taken into account by the introduction of a temperature anomaly correction of the evapotranspiration. In this study daily values of potential evapotranspiration calculated with the Priestley-Taylor method were used as input to the model. The required net radiation estimations were calculated from routine weather observations including cloudiness. Potential evapotranspiration was calculated on a three hour basis over a 20-year period. Model simulations using different input data on the potential evapotranspiration were made for three drainage basins (3,500-4,300 km(2)) in Sweden. The Priestley-Taylor evapotranspiration generally gave small improvements of the runoff simulations. The simple temperature anomaly correction method gave improvements of the same size.

  • 264. Gastgifvars, Maria
    et al.
    Lauri, Hannu
    Sarkanen, Annakaisa
    Myrberg, Kai
    Andrejev, Oleg
    Ambjörn, Cecilia
    SMHI, Affärsverksamhet.
    Modelling surface drifting of buoys during a rapidly-moving weather front in the Gulf of Finland, Baltic Sea2006Ingår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 70, nr 4, s. 567-576Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Gulf of Finland is an elongated estuary located in the north-eastern extremity of the Baltic Sea. This semi-enclosed sea-area is subject to heavy sea traffic, and is one of the main risk areas for oil accidents in the Baltic. The continuous development and validation of operational particle drift and oil-spill forecasting systems is thus seen to be essential for this sea-area. Here, the results of a three-day drift experiment in May 2003 are discussed. The field studies were performed using GPS-positioned surface floating buoys. The aim of this paper is to evaluate how well models can reproduce the drift of these buoys. Model simulations, both in forecast and hindcast modes. were carried out by three different 3D hydrodynamic models, the results of which are evaluated by comparing the calculated drifts with observations. These models were forced by HIRLAM (High Resolution Limited Area Model) and ECMWF (European Centre for Medium-Range Weather Forecasts) meteorological forecast fields. The simulated drift of the buoys showed a good agreement with observations even when, during the study period, a rapidly-changing wind situation was observed to affect the investigation area; in this situation the winds turned about 100 degrees in half an hour. In such a case it is a very complicated task to forecast the drifters' routes: there is a need to regularly update the meteorological forcing fields and to use these regularly-updated fields throughout the simulations. It is furthermore recommended that forecasts should be made using several circulation models and several meteorological forecasts, in order to get an overview of the accuracy of the forecasted drifts and related differences in between the forecasts. (c) 2006 Elsevier Ltd. All rights reserved.

  • 265. Gastgifvars, Maria
    et al.
    Mueller-Navarra, Sylvin
    Funkquist, Lennart
    SMHI, Forskningsavdelningen, Oceanografi.
    Huess, Vibeke
    Performance of operational systems with respect to water level forecasts in the Gulf of Finland2008Ingår i: Ocean Dynamics, ISSN 1616-7341, E-ISSN 1616-7228, Vol. 58, nr 2, s. 139-153Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper is devoted to the validation of water level forecasts in the Gulf of Finland. Daily forecasts produced by four setups of operational, three-dimensional Baltic Sea oceanographic models are analyzed using statistical means and are compared with water level observations at three Finnish stations located on the northern coast of the Gulf of Finland. The overall conclusion is that the operational systems were skillful in forecasting water level variations during the study period from November 1, 2003, to January 31, 2005. The factors causing differences between the water level forecasts of different models are discussed as well. An important task of operational sea level forecasting services is to provide accurate and early information about extreme water levels, both positive and negative surges. During the study period, two major winter storms occurred which caused coastal flooding in the region. According to our analysis, the operational models forecast the rise of water levels during these events rather successfully. Nowadays, operational forecasts can provide early warnings of extreme water levels at least 1 day in advance, which may be regarded as a minimum requirement for an operational forecasting system. The paper concludes that the models generally performed very well, with over 93% of the hourly water level forecasts found to be within the range of +/- 15 cm of the observed water levels, and with the timing of the water level peaks accurately predicted. Further discussion and studies dealing with the assessment of the skills of both operational meteorological and oceanographic forecasts, especially in connection with rare surge events, will be necessary. Skill assessment of operational oceanographic models would be relatively easy if acceptable error limits or a quality system was developed for the Baltic Sea operational models.

  • 266. Gelfan, Alexander
    et al.
    Gustafsson, David
    SMHI, Forskningsavdelningen, Hydrologi.
    Motovilov, Yury
    Arheimer, Berit
    SMHI, Forskningsavdelningen, Hydrologi.
    Kalugin, Andrey
    Krylenko, Inna
    Lavrenov, Alexander
    Climate change impact on the water regime of two great Arctic rivers: modeling and uncertainty issues2017Ingår i: Climatic Change, ISSN 0165-0009, E-ISSN 1573-1480, Vol. 141, nr 3, s. 499-515Artikel i tidskrift (Refereegranskat)
  • 267. Gelfan, Alexander
    et al.
    Gustafsson, David
    SMHI, Forskningsavdelningen, Hydrologi.
    Motovilov, Yury
    Arheimer, Berit
    SMHI, Forskningsavdelningen, Hydrologi.
    Kalugin,, Andrey
    Krylenko,, Inna
    Lavrenov, Alexander
    Climate change impact on the water regime of two great Arctic rivers: modeling and uncertainty issues2016Ingår i: Climatic Change, ISSN 0165-0009, E-ISSN 1573-1480, s. 1-17Artikel i tidskrift (Refereegranskat)
  • 268.
    Gidhagen, Lars
    SMHI, Forskningsavdelningen, Luftmiljö.
    COASTAL UPWELLING IN THE BALTIC SEA - SATELLITE AND INSITU MEASUREMENTS OF SEA-SURFACE TEMPERATURES INDICATING COASTAL UPWELLING1987Ingår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 24, nr 4, s. 449-462Artikel i tidskrift (Refereegranskat)
  • 269. Giorgetti, A.
    et al.
    Partescano, E.
    Barth, A.
    Buga, L.
    Gatti, J.
    Giorgi, G.
    Iona, A.
    Lipizer, M.
    Holdsworth, N.
    Larsen, M. M.
    Schaap, D.
    Vinci, M.
    Wenzer, Magnus
    SMHI, Samhälle och säkerhet.
    EMODnet Chemistry Spatial Data Infrastructure for marine observations and related information2018Ingår i: Ocean and Coastal Management, ISSN 0964-5691, E-ISSN 1873-524X, Vol. 166, s. 9-17Artikel i tidskrift (Refereegranskat)
  • 270. Gleeson, Tom
    et al.
    Marklund, Lars
    SMHI, Forskningsavdelningen, Hydrologi.
    Smith, Leslie
    Manning, Andrew H.
    Classifying the water table at regional to continental scales2011Ingår i: Geophysical Research Letters, ISSN 0094-8276, E-ISSN 1944-8007, Vol. 38, artikel-id L05401Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Water tables at regional to continental scales can be classified into two distinct types: recharge-controlled water tables that are largely disconnected from topography and topography-controlled water tables that are closely tied to topography. We use geomatic synthesis of hydrologic, geologic and topographic data sets to quantify and map water-table type over the contiguous United States using a dimensionless criterion introduced by Haitjema and Mitchell-Bruker (2005), called the water-table ratio, which differentiates water-table type. Our analysis indicates that specific regions of the United States have broadly contiguous and characteristic water-table types. Water-table ratio relates to water-table depth and the potential for regional groundwater flow. In regions with recharge-controlled water tables, for example the Southwest or Rocky Mountains, USA, water-tables depths are generally greater and more variable and regional groundwater flow is generally more important as a percentage of the watershed budget. Water-table depths are generally shallow and less variable, and regional groundwater flow is limited in areas with topography-controlled water tables such as the Northeast USA. The water-table ratio is a simple but powerful criterion for evaluating regional groundwater systems over broad areas. Citation: Gleeson, T., L. Marklund, L. Smith, and A. H. Manning (2011), Classifying the water table at regional to continental scales, Geophys. Res. Lett., 38, L05401, doi: 10.1029/2010GL046427.

  • 271. Godhe, Anna
    et al.
    Cusack, Caroline
    Pedersen, John
    Andersen, Per
    Anderson, Donald M.
    Bresnan, Eileen
    Cembella, Allan
    Dahl, Einar
    Diercks, Sonja
    Elbraechter, Malte
    Edler, Lars
    SMHI, Forskningsavdelningen, Oceanografi.
    Galluzzi, Luca
    Gescher, Christine
    Gladstone, Melissa
    Karlson, Bengt
    SMHI, Forskningsavdelningen, Oceanografi.
    Kulis, David
    LeGresley, Murielle
    Lindahl, Odd
    Marin, Roman
    McDermott, Georgina
    Medlin, Linda K.
    Naustvoll, Lars-Johan
    Penna, Antonella
    Toebe, Kerstin
    Intercalibration of classical and molecular techniques for identification of Alexandrium fundyense (Dinophyceae) and estimation of cell densities2007Ingår i: Harmful Algae, ISSN 1568-9883, E-ISSN 1878-1470, Vol. 6, nr 1, s. 56-72Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A workshop with the aim to compare classical and molecular techniques for phytoplankton enumeration took place at Kristineberg Marine Research Station, Sweden, in August 2005. Seventeen different techniques - nine classical microscopic-based and eight molecular methods - were compared. Alexandrium fundyense was the target organism in four experiments. Experiment 1 was designed to determine the range of cell densities over which the methods were applicable. Experiment 2 tested the species specificity of the methods by adding Alexandrium ostenfeldii, to samples containing A. fundyense. Experiments 3 and 4 tested the ability of the methods to detect the target organism within a natural phytoplankton community. Most of the methods could detect cells at the lowest concentration tested, 100 cells L-1, but the variance was high for methods using small volumes, such as counting chambers and slides. In general, the precision and reproducibility of the investigated methods increased with increased target cell concentration. Particularly molecular methods were exceptions in that their relative standard deviation did not vary with target cell concentration. Only two of the microscopic methods and three of the molecular methods had a significant linear relationship between their cell count estimates and the A. fundyense concentration in experiment 2, where the objective was to discriminate that species from a morphologically similar and genetically closely related species. None of the investigated methods were affected by the addition of a natural plankton community background matrix in experiment 3. The results of this study are discussed in the context of previous intercomparisons and the difficulties in defining the absolute, true target cell concentration. (c) 2006 Elsevier B.V. All rights reserved.

  • 272. 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.

  • 273. Goerlandt, Floris
    et al.
    Goite, Habtamnesh
    Banda, Osiris A. Valdez
    Höglund, Anders
    SMHI, Forskningsavdelningen, Oceanografi.
    Ahonen-Rainio, Paula
    Lensu, Mikko
    An analysis of wintertime navigational accidents in the Northern Baltic Sea2017Ingår i: Safety Science, ISSN 0925-7535, E-ISSN 1879-1042, Vol. 92, s. 66-84Artikel i tidskrift (Refereegranskat)
  • 274. Golbeck, Inga
    et al.
    Li, Xin
    Janssen, Frank
    Bruening, Thorger
    Nielsen, Jacob W.
    Huess, Vibeke
    Soderkvist, Johan
    Buchmann, Bjarne
    Siiria, Simo-Matti
    Vaha-Piikkio, Olga
    Hackett, Bruce
    Kristensen, Nils M.
    Engedahl, Harald
    Blockley, Ed
    Sellar, Alistair
    Lagemaa, Priidik
    Ozer, Jose
    Legrand, Sebastien
    Ljungemyr, Patrik
    SMHI, Samhälle och säkerhet.
    Axell, Lars
    SMHI, Forskningsavdelningen, Oceanografi.
    Uncertainty estimation for operational ocean forecast products-a multi-model ensemble for the North Sea and the Baltic Sea2015Ingår i: Ocean Dynamics, ISSN 1616-7341, E-ISSN 1616-7228, Vol. 65, nr 12, s. 1603-1631Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Multi-model ensembles for sea surface temperature (SST), sea surface salinity (SSS), sea surface currents (SSC), and water transports have been developed for the North Sea and the Baltic Sea using outputs from several operational ocean forecasting models provided by different institutes. The individual models differ in model code, resolution, boundary conditions, atmospheric forcing, and data assimilation. The ensembles are produced on a daily basis. Daily statistics are calculated for each parameter giving information about the spread of the forecasts with standard deviation, ensemble mean and median, and coefficient of variation. High forecast uncertainty, i.e., for SSS and SSC, was found in the Skagerrak, Kattegat (Transition Area between North Sea and Baltic Sea), and the Norwegian Channel. Based on the data collected, longer-term statistical analyses have been done, such as a comparison with satellite data for SST and evaluation of the deviation between forecasts in temporal and spatial scale. Regions of high forecast uncertainty for SSS and SSC have been detected in the Transition Area and the Norwegian Channel where a large spread between the models might evolve due to differences in simulating the frontal structures and their movements. A distinct seasonal pattern could be distinguished for SST with high uncertainty between the forecasts during summer. Forecasts with relatively high deviation from the multi-model ensemble (MME) products or the other individual forecasts were detected for each region and each parameter. The comparison with satellite data showed that the error of the MME products is lowest compared to those of the ensemble members.

  • 275. Gonzalez-Pola, Cesar
    et al.
    Fratantoni, Paula
    Larsen, Karin M. H.
    Holliday, N. Penny
    Dye, Stephen
    Mork, Kjell Arne
    Beszczynska-Moller, Agnieszka
    Valdimarsson, Hedinn
    Trofimov, Alexander
    Parner, Hjalte
    Klein, Holger
    Cisewski, Boris
    Fontan, Almudena
    Lyons, Kieran
    Kolodziejczyk, Nicolas
    Grana, Rocio
    Linders, Johanna
    SMHI, Samhälle och säkerhet.
    Wodzinowski, Tycjan
    Goszczko, Ilona
    Cusack, Caroline
    The ICES Working Group on Oceanic Hydrography: A Bridge From In-situ Sampling to the Remote Autonomous Observation Era2019Ingår i: Frontiers in Marine Science, E-ISSN 2296-7745, Vol. 6, artikel-id UNSP 103Artikel i tidskrift (Refereegranskat)
  • 276. Gosling, S. N
    et al.
    Zaherpour, J.
    Mount, N.
    Hattermann, F. F.
    Dankers, R.
    Arheimer, Berit
    SMHI, Forskningsavdelningen, Hydrologi.
    Breuer, L.
    Ding, J.
    Haddeland, I.
    Kumar, R.
    Kundu, D.
    Liu, J.
    van Griensven, A.
    Veldkamp, T.I.E.
    Vetter, T.
    Wang, X.
    Zhan, X.
    A comparison of changes in river runoff from multiple global and catchment-scale hydrological models under global warming scenarios of 1°C, 2°C and 3°C2016Ingår i: Climatic Change, ISSN 0165-0009, E-ISSN 1573-1480, s. 1-19Artikel i tidskrift (Refereegranskat)
  • 277. Gosling, Simon N.
    et al.
    Zaherpour, Jamal
    Mount, Nick J.
    Hattermann, Fred F.
    Dankers, Rutger
    Arheimer, Berit
    SMHI, Forskningsavdelningen, Hydrologi.
    Breuer, Lutz
    Ding, Jie
    Haddeland, Ingjerd
    Kumar, Rohini
    Kundu, Dipangkar
    Liu, Junguo
    van Griensven, Ann
    Veldkamp, Ted I. E.
    Vetter, Tobias
    Wang, Xiaoyan
    Zhang, Xinxin
    A comparison of changes in river runoff from multiple global and catchment-scale hydrological models under global warming scenarios of 1 degrees C, 2 degrees C and 3 degrees C (vol 141, pg 577, 2017)2017Ingår i: Climatic Change, ISSN 0165-0009, E-ISSN 1573-1480, Vol. 141, nr 3, s. 597-598Artikel i tidskrift (Refereegranskat)
  • 278. Gothe, Emma
    et al.
    Friberg, Nikolai
    Kahlert, Maria
    Temnerud, Johan
    SMHI, Forskningsavdelningen, Hydrologi.
    Sandin, Leonard
    Headwater biodiversity among different levels of stream habitat hierarchy2014Ingår i: Biodiversity and Conservation, ISSN 0960-3115, E-ISSN 1572-9710, Vol. 23, nr 1, s. 63-80Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    With the current loss of biodiversity and threats to freshwater ecosystems, it is crucial to identify hot-spots of biodiversity and on which spatial scale they can be resolved. Conservation and management of these important ecosystems needs insight into whether most of the regional biodiversity (i.e. gamma-diversity) can be found locally (i.e. high alpha-diversity) or whether it is distributed across the region (i.e. high beta-diversity). Biodiversity patterns of benthic macroinvertebrates and diatoms were studied in 30 headwater streams in five Swedish catchments by comparing the relative contribution of alpha- and beta-diversity to gamma-diversity between two levels of stream habitat hierarchy (catchment and region level). The relationship between species community structure and local environmental factors was also assessed. Our results show that both alpha- and beta-diversity made a significant contribution to gamma-diversity. beta-diversity remained relatively constant between the two levels of habitat hierarchy even though local environmental control of the biota decreased from the catchment to the region level. To capture most of headwater gamma-diversity, management should therefore target sites that are locally diverse, but at the same time select sites so that beta-diversity is maximized. As environmental control of the biota peaked at the catchment level, the conservation of headwater stream diversity is likely to be most effective when management targets environmental conditions across multiple local sites within relatively small catchments.

  • 279.
    Gotthardsson, Martin
    SMHI, Samhälle och säkerhet.
    Översvämningskänsliga områden i Sverige: Svenskt Vattenarkiv1994Rapport (Övrigt vetenskapligt)
    Abstract [sv]

    Länsstyrelserna fick genom Miljö och Energidepartementet 1989-06-29 i uppdrag att utreda vissa frågor rörande dammsäkerhet mm. Målsättningen var att förbättra planeringen för att förhindra översvämningsskador genom aktualisering av kommunernas fysiska planering och med genomförande av åtgärder. Utredningarna skulle vara klara senast den 22 februari l990. SMHI har erhållit kopior på länens redovisningar från 23 län, som rör översvämningskänsliga områden fram till 1990 och har upprättat ett nationellt register över dessa. Antalet redovisade områden för varje län framgår av bifogad karta. Siffrorna är inte helt jämförbara på grund av skillnader i redovisningssätt, men ger ändå en bra bild av fördelningen. Totalt redovisades 647 områden från länen. Följande personer på SMHl har arbetat med översvämningsregistret nämligen Torbjörn Lindkvist, Bernth Samuelsson, Stig Nilsson och framför allt Todor Milanov. Denna rapport har sammanställts på Analysenheten inom affärsområde Samhälle av Martin Gotthardssonmed hjälp av Maja Brandt.

  • 280.
    Gotthardsson, Martin
    et al.
    SMHI, Samhälle och säkerhet.
    Lindell, Sten
    SMHI, Affärsverksamhet.
    Hydrologiska stationsnät 1989: Svenskt Vattenarkiv1989Rapport (Övrigt vetenskapligt)
  • 281.
    Gotthardsson, Martin
    et al.
    SMHI, Samhälle och säkerhet.
    Rystam, Pia
    SMHI, Samhälle och säkerhet.
    Westman, Sven-Erik
    SMHI.
    Hydrologiska stationsnät 1992 / Hydrological network: Svenskt Vattenarkiv1992Rapport (Övrigt vetenskapligt)
  • 282.
    Graham, Phil
    et al.
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Andersson, Lotta
    SMHI, Samhälle och säkerhet.
    Horan, Mark
    Kunz, Richard
    Lumsden, Trevor
    Schulze, Roland
    Warburton, Michele
    Wilk, Julie
    Yang, Wei
    SMHI, Forskningsavdelningen, Hydrologi.
    Using multiple climate projections for assessing hydrological response to climate change in the Thukela River Basin, South Africa2011Ingår i: Physics and Chemistry of the Earth, ISSN 1474-7065, E-ISSN 1873-5193, Vol. 36, nr 14-15, s. 727-735Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study used climate change projections from different regional approaches to assess hydrological effects on the Thukela River Basin in KwaZulu-Natal, South Africa. Projecting impacts of future climate change onto hydrological systems can be undertaken in different ways and a variety of effects can be expected. Although simulation results from global climate models (GCMs) are typically used to project future climate, different outcomes from these projections may be obtained depending on the GCMs themselves and how they are applied, including different ways of downscaling from global to regional scales. Projections of climate change from different downscaling methods, different global climate models and different future emissions scenarios were used as input to simulations in a hydrological model to assess climate change impacts on hydrology. A total of 10 hydrological change simulations were made, resulting in a matrix of hydrological response results. This matrix included results from dynamically downscaled climate change projections from the same regional climate model (RCM) using an ensemble of three GCMs and three global emissions scenarios, and from statistically downscaled projections using results from five GCMs with the same emissions scenario. Although the matrix of results does not provide complete and consistent coverage of potential uncertainties from the different methods, some robust results were identified. In some regards, the results were in agreement and consistent for the different simulations. For others, particularly rainfall, the simulations showed divergence. For example, all of the statistically downscaled simulations showed an annual increase in precipitation and corresponding increase in river runoff, while the RCM downscaled simulations showed both increases and decreases in runoff. According to the two projections that best represent runoff for the observed climate, increased runoff would generally be expected for this basin in the future. Dealing with such variability in results is not atypical for assessing climate change impacts in Africa and practitioners are faced with how to interpret them. This work highlights the need for additional, well-coordinated regional climate downscaling for the region to further define the range of uncertainties involved. (C) 2011 Elsevier Ltd. All rights reserved.

  • 283.
    Graham, Phil
    et al.
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Andreasson, Johan
    SMHI, Affärsverksamhet.
    Carlsson, Bengt
    SMHI, Forskningsavdelningen, Hydrologi.
    Assessing climate change impacts on hydrology from an ensemble of regional climate models, model scales and linking methods - a case study on the Lule River basin2007Ingår i: Climatic Change, ISSN 0165-0009, E-ISSN 1573-1480, Vol. 81, s. 293-307Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper investigates how using different regional climate model (RCM) simulations affects climate change impacts on hydrology in northern Europe using an offline hydrological model. Climate change scenarios from an ensemble of seven RCMs, two global climate models (GCMs), two global emissions scenarios and two RCMs of varying resolution were used. A total of 15 climate change simulations were included in studies on the Lule River basin in Northern Sweden. Two different approaches to transfer climate change from the RCMs to hydrological models were tested. A rudimentary estimate of change in laydropower potential on the Lule River due to climate change was also made. The results indicate an overall increase in river flow, earlier spring peak flows and an increase in hydropower potential. The two approaches for transferring the signal of climate change to the hydrological impacts model gave similar mean results, but considerably different seasonal dynamics, a result that is highly relevant for other types of climate change impacts studies.

  • 284.
    Graham, Phil
    et al.
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Bergström, Sten
    SMHI, Forskningsavdelningen, Hydrologi.
    Land surface modelling in hydrology and meteorology - lessons learned from the Baltic Basin2000Ingår i: Hydrology and Earth System Sciences, ISSN 1027-5606, E-ISSN 1607-7938, Vol. 4, nr 1, s. 13-22Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    By both tradition and purpose, the land parameterization schemes of hydrological and meteorological models differ greatly. Meteorologists are concerned primarily with solving the energy balance, whereas hydrologists are most interested in the water balance. Meteorological climate models typically have multi-layered soil parameterisation that solves temperature fluxes numerically with diffusive equations. The same approach is carried over to a similar treatment of water transport. Hydrological models are not usually so interested in soil temperatures, but must provide a reasonable representation of soil moisture to get runoff right. To treat the heterogeneity of the soil, many hydrological models use only one laver with a statistical representation of soil variability. Such a hydrological model can be used on large scales while taking subgrid variability into account. Hydrological models also include lateral transport of water - an imperative if river discharge is to be estimated. The concept of a complexity chain for coupled modelling systems is introduced, together with considerations for mixing model components. Under BALTEX (Baltic Sea Experiment) and SWECLIM (Swedish Regional Climate Modelling Programme), a large-scale hydrological model of runoff in the Baltic Basin is used to review atmospheric climate model simulations. This incorporates both the runoff record and hydrological modelling experience into atmospheric model development. Results from two models are shown. A conclusion is that the key to improved models may be less complexity. Perhaps the meteorological models should keep their multi-layered approach for modelling soil temperature, bur add a simpler, yet physically consistent, hydrological approach for modelling snow processes and water transport in the soil.

  • 285.
    Graham, Phil
    et al.
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Bergström, Sten
    SMHI, Forskningsavdelningen, Hydrologi.
    Water balance modelling in the Baltic Sea drainage basin - analysis of meteorological and hydrological approaches2001Ingår i: Meteorology and atmospheric physics (Print), ISSN 0177-7971, E-ISSN 1436-5065, Vol. 77, nr 1-4, s. 45-60Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Efforts to understand and simulate the global climate in numerical models have led to regional studies of the energy and water balance. The Baltic Basin provides a continental scale test basin where meteorology, oceanography and hydrology all can meet. Using a simple conceptual approach, a large-scale hydrological model of the water balance of the total Baltic Sea Drainage Basin (HBV-Baltic) was used to simulate the basinwide water balance components for the present climate and to evaluate the land surface components of atmospheric climate models. It has been used extensively in co-operative BALTEX (The Baltic Sea Experiment) research and within SWECLIM (Swedish Regional Climate Modelling Programme) to support continued regional climate model development. This helps to identify inconsistencies in bath meteorological and hydrological models. One result is that compensating errors are evident in the snow routines of the atmospheric models studied. The use of HBV-Baltic has greatly improved the dialogue between hydrological and meteorological modellers within the Baltic Basin research community. It is concluded that conceptual hydrological models, although far from being complete, play an important role in the realm of continental scale hydrological modelling. Atmospheric models benefit from the experience of hydrological modellers in developing simpler, yet more effective land surface parameterisations. This basic modelling tool for simulating the large-scale water balance of the Baltic Sea drainage basin is the only existing hydrological model that covers the entire basin and will continue to be used until more detailed models can be successfully applied at this scale.

  • 286.
    Graham, Phil
    et al.
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Jacob, D
    Using large-scale hydrologic modeling to review runoff generation processes in GCM climate models2000Ingår i: Meteorologische Zeitschrift, ISSN 0941-2948, E-ISSN 1610-1227, Vol. 9, nr 1, s. 49-57Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A large-scale application of the Swedish HBV hydrologic model was used to model the daily water balance of total runoff to the Baltic Sea. Ten-year present atmospheric climate model simulations from the ECHAM4/T106 global climate model were summarized on a runoff catchment basis. Climate model daily temperature and precipitation for the Baltic region were input to the water balance model for intercomparison runs. Comparison of results from the water balance model - with climate model input - to direct results from the climate model provides critical review of the behavior of the climate model. This: helped pinpoint systematic compensating errors in the land parameterization scheme.

  • 287. Grahn, T.
    et al.
    Olsson, Jonas
    SMHI, Forskningsavdelningen, Hydrologi.
    Insured flood damage in Sweden, 1987-20132019Ingår i: Journal of Flood Risk Management, ISSN 1753-318X, E-ISSN 1753-318X, Vol. 12, nr 3, artikel-id UNSP e12465Artikel i tidskrift (Refereegranskat)
  • 288. Granhag, Lena
    et al.
    Moller, Lene Friis
    Hansson, Lars J.
    SMHI, Forskningsavdelningen, Oceanografi.
    Size-specific clearance rates of the ctenophore Mnemiopsis leidyi based on in situ gut content analyses2011Ingår i: Journal of Plankton Research, ISSN 0142-7873, E-ISSN 1464-3774, Vol. 33, nr 7, s. 1043-1052Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The ctenophore Mnemiopsis leidyi can consume large amounts of zooplankton prey. However, quantitative measurements of feeding rates, based on field data, are scarce. We measured the time required by the invasive M. leidyi to digest naturally occurring prey species in the Gullmar fjord, Sweden. Digestion times were related to prey size and type, number of prey in the gut and size of the predator. Large prey species or many prey in the gut resulted in longer digestion times compared with small or few prey, but digestion time also varied with the size of M. leidyi. The prey-and predator-specific digestion times were used together with in situ prey concentrations and gut contents of M. leidyi to calculate the clearance rates. Clearance rate as a function of ctenophore size is presented for the most abundant mesozooplankton: Acartia sp., Oithona sp., Oikopleura dioica and Penilia avirostris. On the basis of the relation between digestion time and the carbon content ratio between prey and predator, we discuss the possible effects of mixed prey assemblages on the estimates of clearance rates.

  • 289. Grimvall, A
    et al.
    Stalnacke, P
    Tonderski, Andrzej
    SMHI.
    Time scales of nutrient losses from land to sea - a European perspective2000Ingår i: Ecological Engineering: The Journal of Ecotechnology, ISSN 0925-8574, E-ISSN 1872-6992, Vol. 14, nr 4, s. 363-371Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Empirical data regarding the time scales of nutrient losses from soil to water and land to sea were reviewed. The appearance of strongly elevated concentrations of nitrogen and phosphorus in major European rivers was found to be primarily a post-war phenomenon. However. the relatively rapid water quality response to increased point source emissions and intensified agriculture does not imply that the reaction to decreased emissions will be equally rapid. Long-term fertilisation experiments have shown that important processes in the large-scale turnover of nitrogen operate on a time scale of decades up to at least a century, and in several major Eastern European rivers there is a remarkable lack of response to the dramatic decrease in the use of commercial fertilisers that started in the late 1980s. In Western Europe, studies of decreased phosphorus emissions have shown that riverine loads of this element can be rapidly reduced from high to moderate levels, whereas a further reduction, if achieved at all, may take decades. Together, the reviewed studies showed that the inertia of the systems that control the loss of nutrients from land to sea was underestimated when the present goal of a 50% reduction of the input of nutrients to the Baltic Sea and the North Sea was adopted. (C) 2000 Elsevier Science B.V. All rights reserved.

  • 290. Grimvall, Anders
    et al.
    von Bromssen, Claudia
    Lindström, Göran
    SMHI, Forskningsavdelningen, Hydrologi.
    Using process-based models to filter out natural variability in observed concentrations of nitrogen and phosphorus in river water2014Ingår i: Environmental Monitoring & Assessment, ISSN 0167-6369, E-ISSN 1573-2959, Vol. 186, nr 8, s. 5135-5152Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Advances in process-based modelling of loads of nitrogen and phosphorus carried by rivers have created new possibilities to interpret time series of water quality data. We examined how model runs with constant anthropogenic forcing can be used to estimate and filter out weather-driven variation in observational data and, thereby, draw attention to other features of such data. An assessment of measured and modelled nutrient concentrations at the outlets of 45 Swedish rivers provided promising results for total nitrogen. In particular, joint analyses of observational data and outputs from the catchment model S-HYPE strengthened the evidence that downward trends in nitrogen were due to mitigation measures in agriculture. Evaluation of modelled and observed total phosphorus concentrations revealed considerable bias in the collection or chemical analysis of water samples and also identified weaknesses in the model outputs. Together, our results highlight the need for more efficient two-way communication between environmental modelling and monitoring.

  • 291.
    Groger, Matthias
    et al.
    SMHI, Forskningsavdelningen, Oceanografi.
    Arneborg, Lars
    SMHI, Forskningsavdelningen, Oceanografi.
    Dieterich, Christian
    SMHI, Forskningsavdelningen, Oceanografi.
    Höglund, Anders
    SMHI, Forskningsavdelningen, Oceanografi.
    Meier, Markus
    SMHI, Forskningsavdelningen, Oceanografi.
    Summer hydrographic changes in the Baltic Sea, Kattegat and Skagerrak projected in an ensemble of climate scenarios downscaled with a coupled regional ocean-sea ice-atmosphere model2019Ingår i: Climate Dynamics, ISSN 0930-7575, E-ISSN 1432-0894, Vol. 53, nr 9-10, s. 5945-5966Artikel i tidskrift (Refereegranskat)
  • 292. Groger, Matthias
    et al.
    Dieterich, Christian
    SMHI, Forskningsavdelningen, Oceanografi.
    Meier, Markus
    SMHI, Forskningsavdelningen, Oceanografi.
    Schimanke, Semjon
    SMHI, Forskningsavdelningen, Oceanografi.
    Thermal air-sea coupling in hindcast simulations for the North Sea and Baltic Sea on the NW European shelf2015Ingår i: Tellus. Series A, Dynamic meteorology and oceanography, ISSN 0280-6495, E-ISSN 1600-0870, Vol. 67, artikel-id 26911Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This article compares interactively coupled atmosphere-ocean hindcast simulations with stand-alone runs of the atmosphere and ocean models using the recently developed regional ocean-atmosphere model NEMO-Nordic for the North Sea and Baltic Sea. In the interactively coupled run, the ocean and the atmosphere components were allowed to exchange mass, momentum and heat every 3 h. Our results show that interactive coupling significantly improves simulated winter sea surface temperatures (SSTs) in the Baltic Sea. The ocean and atmosphere stand-alone runs, respectively, resulted in too low sea surface and air temperatures over the Baltic Sea. These two runs suffer from too cold prescribed ERA40 SSTs, which lower air temperatures and weaken winds in the atmosphere only run. In the ocean-only run, the weaker winds additionally lower the vertical mixing thereby lowering the upward transport of warmer subpycnocline waters. By contrast, in the interactively coupled run, the ocean-atmosphere heat exchange evolved freely and demonstrated good skills in reproducing observed surface temperatures. Despite the strong impact on oceanic and atmospheric variables in the coupling area, no far reaching influence on atmospheric variables over land can be identified. In perturbation experiments, the different dynamics of the two coupling techniques is investigated in more detail by implementing strong positive winter temperature anomalies in the ocean model. Here, interactive coupling results in a substantially higher preservation of heat anomalies because the atmosphere also warmed which damped the ocean to atmosphere heat transfer. In the passively coupled set-up, this atmospheric feedback is missing, which resulted in an unrealistically high oceanic heat loss. The main added value of interactive air-sea coupling is twofold: (1) the elimination of any boundary condition at the air-sea interface and (2) the more realistic dynamical response to perturbations in the ocean-atmosphere heat balance, which will be essential in climate warming scenarios.

  • 293. Gustafsson, Bo G.
    et al.
    Schenk, Frederik
    Blenckner, Thorsten
    Eilola, Kari
    SMHI, Forskningsavdelningen, Oceanografi.
    Meier, Markus
    SMHI, Forskningsavdelningen, Oceanografi.
    Muller-Karulis, Barbel
    Neumann, Thomas
    Ruoho-Airola, Tuija
    Savchuk, Oleg P.
    Zorita, Eduardo
    Reconstructing the Development of Baltic Sea Eutrophication 1850-20062012Ingår i: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 41, nr 6, s. 534-548Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A comprehensive reconstruction of the Baltic Sea state from 1850 to 2006 is presented: driving forces are reconstructed and the evolution of the hydrography and biogeochemical cycles is simulated using the model BALTSEM. Driven by high resolution atmospheric forcing fields (HiResAFF), BALTSEM reproduces dynamics of salinity, temperature, and maximum ice extent. Nutrient loads have been increasing with a noteworthy acceleration from the 1950s until peak values around 1980 followed by a decrease continuing up to present. BALTSEM shows a delayed response to the massive load increase with most eutrophic conditions occurring only at the end of the simulation. This is accompanied by an intensification of the pelagic cycling driven by a shift from spring to summer primary production. The simulation indicates that no improvement in water quality of the Baltic Sea compared to its present state can be expected from the decrease in nutrient loads in recent decades.

  • 294.
    Göransson, Bent
    et al.
    SMHI, Samhälle och säkerhet.
    Brandt, Maja
    SMHI, Samhälle och säkerhet.
    Wittgren, Hans Bertil
    SMHI, Forskningsavdelningen.
    Markläckage och vattendragstransport av kväve och fosfor i Roxen/Glan-systemet, Östergötland1991Rapport (Övrigt vetenskapligt)
    Abstract [sv]

    Markläckage, vattendragstransport och sjöretention av kväve har beräknats med en modell (PULS-N) i de delar av Motala Ströms avrinningsområde, som faller inom Linköpings, Finspångs och Norrköpings kommuner. Modelleringar har gjorts för åren 1975-89 och verifierats mot befintliga mätdata.

    Modellen använder tre olika typer av indata: meterologiska uppgifter om temperatur och nederbörd, geografiska uppgifter om vattendelarnas läge och arealens fördelning på olika markanvändning, samt kemiska data om typiska halter i avrinnande vatten från olika typer åv markanvändning

    Markläckaget av kväve domineras av bidrag från åker med sädesodling. Från de delar av avrinningsområdet, som ungefärligen motsvaras av Linköpings kommun, svarade sädesodling för 31 % av arealen men 76 % av markläckaget. För Finspång var motsvarande siffror 4 resp. 18 % och för Norrköping 9 resp. 32 %. Dessa procentuella uppgifter på markläckaget gäller 1989 men varierar inte nämnvärt mellan olika år.

    Kvävetransporten i vattendragen visar kraftiga mellanårsvariationer, som huvudsakligen förklaras av skillnader i nederbörd. I de fall, då modellerade värden avviker från värden beräknade ur uppmätta koncentrationer, är detta en indikation på förändringar som inte förklaras av väderfaktorer. Exempelvis var 1977 ett år med starkt förhöjd uttransport ur sjön Glan. Uttransporten kan inte förklaras tillfredställande av en motsvarande hög intransport, vilket tyder på en frisättning av kväve från sjösedimenten i Glan.

    Både Roxen och Glan fungerar som kvävefällor. I genomsnitt kvarhölls, på basis av sjöyta, 53 kg/ha·år (17 % ) i Roxen och 36 kg/ha·år (9 % ) i Glan under perioden 1975-89. En orsak till skillnaden är antagligen att nitrat-N-transporten till Roxen är högre än till Glan, trots att total-N-transporten är högre till Glan. Förhållandet mellan nitrat-N och organiskt N i sjöarna speglar att Glan inte är en lika utpräglad slättsjö som Roxen.

    Beräkningarna, med hänsyn tagen till retentionen i sjöarna, visar att punktkällorna (de stora reningsverken och Skärblacka bruk) stod för 27 % av Motala Ströms nettobelastning på Bråviken under perioden 1985-89. Det lokala bidraget från markläckage i de aktuella kommunerna stod för 22 % och intransporten till kommunerna för 51 % .

    Nettotransporterna av fosfor, räknat per ytenhet, är störst inom Linköpings kommuns delar av Svartåns och Motala Ströms (huvudfårans) avrinningsområden.

    Transporten av fosfor från Roxen var under 1975-89 klart större än transporterna till Roxen. Under samma period hade Glan en nettoimport av fosfor.

  • 295. Haapala, J
    et al.
    Meier, Markus
    SMHI, Forskningsavdelningen, Oceanografi.
    Rinne, J
    Numerical investigations of future ice conditions in the Baltic Sea2001Ingår i: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 30, nr 4-5, s. 237-244Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Global climate change is expected to have an effect on the physical and ecological characteristics of the Baltic Sea. Estimates of future climate on the regional scale can be obtained by using either statistical or dynamical downscaling methods of global AOGCM scenario results. In this paper, we use 2 different coupled ice-ocean models of the Baltic Sea to simulate present and future ice conditions around 100 years from present. Two 10-year time slice experiments have been performed using the results of atmospheric climate model simulations as forcing, one representing pre-industrial climate conditions (control simulation), and the other global warming with a 150% increase in CO2 greenhouse gas concentration (scenario simulation). Present-day climatological ice conditions and interannual variability are realistically reproduced by the models. The simulated range of the maximum annual ice extent in the Baltic in both models together is 180 to 420.10(3) km(2) in the control simulation and 45 to 270.10(3) km(2) in the scenario simulation. The range of the maximum annual ice thickness is from 32 to 96 cm and from 11 to 60 cm in the control and scenario simulations, respectively. In contrast to earlier estimates, sea ice is still formed every winter in the Northern Bothnian Bay and in the most Eastern parts of the Gulf of Finland. Overall, the simulated changes of quantities such as ice extent and ice thickness, as well as their interannual variations are relatively similar in both models, which is remarkable, because the 2 coupled ice-ocean model systems have been. developed independently. This increases the reliability of future projections of ice conditions in the Baltic Sea.

  • 296. Haerter, Jan O.
    et al.
    Berg, Peter
    SMHI, Forskningsavdelningen, Hydrologi.
    Moseley, Christopher
    Precipitation onset as the temporal reference in convective self-organization2017Ingår i: Geophysical Research Letters, ISSN 0094-8276, E-ISSN 1944-8007, Vol. 44, nr 12, s. 6450-6459Artikel i tidskrift (Refereegranskat)
  • 297. Haerter, Jan O.
    et al.
    Eggert, Bastian
    Moseley, Christopher
    Piani, Claudio
    Berg, Peter
    SMHI, Forskningsavdelningen, Hydrologi.
    Statistical precipitation bias correction of gridded model data using point measurements2015Ingår i: Geophysical Research Letters, ISSN 0094-8276, E-ISSN 1944-8007, Vol. 42, nr 6, s. 1919-1929Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    It is well known that climate model output data cannot be used directly as input to impact models, e.g., hydrology models, due to climate model errors. Recently, it has become customary to apply statistical bias correction to achieve better statistical correspondence to observational data. As climate model output should be interpreted as the space-time average over a given model grid box and output time step, the status quo in bias correction is to employ matching gridded observational data to yield optimal results. Here we show that when gridded observational data are not available, statistical bias correction can be carried out using point measurements, e.g., rain gauges. Our nonparametric method, which we call scale-adapted statistical bias correction (SABC), is achieved by data aggregation of either the available modeled or gauge data. SABC is a straightforward application of the well-known Taylor hypothesis of frozen turbulence. Using climate model and rain gauge data, we show that SABC performs significantly better than equal-time period statistical bias correction.

  • 298. Hajdu, S
    et al.
    Edler, Lars
    SMHI, Forskningsavdelningen, Oceanografi.
    Olenina, I
    Witek, B
    Spreading and establishment of the potentially toxic dinoflagellate Prorocentrum minimum in the Baltic Sea2000Ingår i: International review of hydrobiology, ISSN 1434-2944, E-ISSN 1522-2632, Vol. 85, nr 5-6, s. 561-575Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    During the last two decades the potentially toxic dinoflagellate Prorocentrum minimum (PAVILLARD) SCHILLER has successfully established itself in the Baltic Sea. It is now a dominant summer species in the southern Baltic proper, and reaches as far into the low salinity of the northern Baltic as the central Gulf of Finland. In the 1990s, it developed several coastal blooms in the eastern and northern Baltic proper, but occurred irregularly between years. Field data show that P. minimum can grow at salinities below 5 PSU, confirming its potential to penetrate farther into the low saline part of the Baltic Sea. Biometric data show that P. minimum cells differ significantly in size between areas in the Baltic Sea.

  • 299. Hakonen, Aron
    et al.
    Anderson, Leif G.
    Engelbrektsson, Johan
    Hulth, Stefan
    Karlson, Bengt
    SMHI, Forskningsavdelningen, Oceanografi.
    A potential tool for high-resolution monitoring of ocean acidification2013Ingår i: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 786, s. 1-7Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Current anthropogenic carbon dioxide emissions generate besides global warming unprecedented acidification rates of the oceans. Recent evidence indicates the possibility that ocean acidification and low oceanic pH may be a major reason for several mass extinctions in the past. However, a major bottleneck for research on ocean acidification is long-term monitoring and the collection of consistent high-resolution pH measurements. This study presents a low-power (<1 W) small sample volume (25 mu L) semiconductor based fluorescence method for real-time ship-board pH measurements at high temporal and spatial resolution (approximately 15 s and 100 m between samples). A 405 nm light emitting diode and the blue and green channels from a digital camera was used for swift detection of fluorescence from the pH sensitive dye 6,8-Dihydroxypyrene-1,3-disulfonic acid in real-time. Main principles were demonstrated by automated continuous measurements of pH in the surface water across the Baltic Sea and the Kattegat region with a large range in salinity (similar to 3-30) and temperature (similar to 0-25 degrees C). Ship-board precision of salinity and temperature adjusted pH measurements were estimated as low as 0.0001 pH units. (C) 2013 Elsevier B. V. All rights reserved.

  • 300. Hall, J.
    et al.
    Arheimer, Berit
    SMHI, Forskningsavdelningen, Hydrologi.
    Aronica, T.
    Bilibashi, A.
    Bohac, M.
    Bonacci, O.
    Borga, M.
    Burlando, P.
    Castellarin, A.
    Chirico, G. B.
    Claps, P.
    Fiala, K.
    Gaal, L.
    Gorbachova, L.
    Gul, A.
    Hannaford, J.
    Kiss, A.
    Kjeldsen, T.
    Kohnova, S.
    Koskela, J. J.
    Macdonald, N.
    Mavrova-Guirguinova, M.
    Ledvinka, O.
    Mediero, L.
    Merz, B.
    Merz, R.
    Molnar, P.
    Montanari, A.
    Osuch, M.
    Parajka, J.
    Perdigao, R. A. P.
    Radevski, I.
    Renard, B.
    Rogger, M.
    Salinas, J. L.
    Sauquet, E.
    Sraj, M.
    Szolgay, J.
    Viglione, A.
    Volpi, E.
    Wilson, D.
    Zaimi, K.
    Bloeschl, G.
    A European Flood Database: facilitating comprehensive flood research beyond administrative boundaries2015Ingår i: CHANGES IN FLOOD RISK AND PERCEPTION IN CATCHMENTS AND CITIES, 2015, s. 89-95Konferensbidrag (Refereegranskat)
    Abstract [en]

    The current work addresses one of the key building blocks towards an improved understanding of flood processes and associated changes in flood characteristics and regimes in Europe: the development of a comprehensive, extensive European flood database. The presented work results from ongoing cross-border research collaborations initiated with data collection and joint interpretation in mind. A detailed account of the current state, characteristics and spatial and temporal coverage of the European Flood Database, is presented. At this stage, the hydrological data collection is still growing and consists at this time of annual maximum and daily mean discharge series, from over 7000 hydrometric stations of various data series lengths. Moreover, the database currently comprises data from over 50 different data sources. The time series have been obtained from different national and regional data sources in a collaborative effort of a joint European flood research agreement based on the exchange of data, models and expertise, and from existing international data collections and open source websites. These ongoing efforts are contributing to advancing the understanding of regional flood processes beyond individual country boundaries and to a more coherent flood research in Europe.

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