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  • 351.
    Pemberton, Per
    et al.
    SMHI, Research Department, Oceanography.
    Nilsson, Johan
    SMHI, Core Services.
    Meier, Markus
    SMHI, Research Department, Oceanography.
    Arctic Ocean freshwater composition, pathways and transformations from a passive tracer simulation2014In: Tellus. Series A, Dynamic meteorology and oceanography, ISSN 0280-6495, E-ISSN 1600-0870, Vol. 66Article in journal (Refereed)
    Abstract [en]

    Freshwater (FW) induced transformations in the upper Arctic Ocean were studied using a coupled regional sea ice-ocean model driven by winds and thermodynamic forcing from a reanalysis of data during the period 1948-2011, focusing on the mean state during 1968-2011. Using passive tracers to mark a number of FW sources and sinks, their mean composition, pathways and export were examined. The distribution of the simulated FW height reproduced the known features of the Arctic Ocean and volume-integrated FW content matched climatological estimates reasonably well. Input from Eurasian rivers and extraction by sea-ice formation dominate the composition of the Arctic FW content whilst Pacific water increases in importance in the Canadian Basin. Though pathways generally agreed with previous studies the locus of the Eurasian runoff shelf-basin transport centred at the Alpha-Mendeleyev ridge, shifting the Pacific-Atlantic front eastwards. A strong coupling between tracers representing Eurasian runoff and sea-ice formation showed how water modified on the shelf spreads across the Arctic and mainly exits through the Fram Strait. Transformation to salinity dependent coordinates showed how Atlantic water is modified by both low-salinity shelf and Pacific waters in an estuary-like overturning producing water masses of intermediate salinity that are exported to the Nordic Seas. A total halocline renewal rate of 1.0 Sv, including both shelf-basin exchange and cross-isohaline flux, was estimated from the transports: both components were of equal magnitude. The model's halocline shelf-basin exchange is dominated by runoff and sea-ice processes at the western shelves (the Barents and Kara seas) and Pacific water at the eastern shelves (the Laptev, East Siberian and Chukchi seas).

  • 352.
    Persson, Christer
    et al.
    SMHI, Research Department, Air quality.
    Magnusson, Mikael
    SMHI, Core Services.
    Kvaliteten i uppmätta nederbördsmängder inom svenska nederbördskemiska stationsnät2003Report (Other academic)
    Abstract [en]

    High quality measurements of precipitation amounts in precipitation chemistry networks are of large importance in order to obtain correct information concerning concentrations in precipitation as well as wet deposition of air pollutants. In this study the quality of measured precipitation amounts at each of three different Swedish precipitation chemistry networks has been investigated. For shorter periods during 1998-2001 quality deficiencies were found at two Swedish EMEP stations. The reason to that seems to be technical problems with the lid samplers used at that network. For the Swedish air and precipitation chemistry network (PMK) and the regional network (REG) deficiencies in precipitation measurements were found for the winter seasons. Very large scatter in precipitation amounts was obtained when comparisons were made with objective interpolated precipitation fields based on all SMHI observations. The reason to this disagreement is assumed to be the use of “snowsacks” on the samplers during the winter half-year regardless of weather condition. These “snow-sacks” are assumed to influence the aerodynamic conditions around the samplers and thus also influence the efficiency in sampling raindrops and snowflakes.

  • 353.
    Persson, Christer
    et al.
    SMHI, Research Department, Air quality.
    Ressner, Elisabet
    SMHI.
    Klein, Thomas
    SMHI, Core Services.
    Nationell miljöövervakning – MATCH-Sverige modellen: Metod- och resultatsammanställning för åren 1999-2002 samt diskussionav osäkerheter, trender och miljömål2004Report (Other academic)
    Abstract [en]

    National air pollution assessments based on the MATCH-Sweden model – Results for the period 1999-2002 The MATCH-Sweden model system is used as a tool for mapping of air pollution deposition and concentration over Sweden and for air pollution assessment studies.The system includes a simplified type of data assimilation of backgroundatmospheric chemistry observations in Sweden and Norway. Over the entire period 1999-2002 the annual sulphur and nitrogen deposition consistently shows a maximum over Southwest Götaland and decreases northwards. An annual air pollution budget for Sweden is determined. During the period of study the Swedish emissions account for 5-7% of the total annual deposition of sulphur in Sweden and for 11-13% of the corresponding NOx-deposition. The Swedish contribution to the total deposition of NHx-nitrogen is, according to the present calculations, about 16%. However, the uncertainty in this value is larger than for sulphur and NOx-nitrogen.Comparisons between results for the year 2000 obtained with MATCH-Sweden and the new “Unified EMEP Eulerian model” (EMEP, 2003) respectively, show good agreement for most parameters. The agreement is much better than observed in earlier comparisons with the old EMEP model. Large differences are found only for long-range transport contribution to the NHx-deposition over Northern Sweden, where MATCH-Sweden calculations indicate larger depositions than EMEP. However, the MATCH-Sweden system – including simplified data assimilation - suffers from a lack of representative air and precipitation NHx-measurements in that area. A tentative estimate of deposition trends over Sweden indicates a 50-55% decrease for sulphur between 1991 and 2002. For NOx- and NHx-nitrogen the corresponding decrease in deposition is only about 15%each.

  • 354.
    Persson, Christer
    et al.
    SMHI, Research Department, Air quality.
    Wern, Lennart
    SMHI, Core Services.
    Beräkningar av svaveldepositionen i Stockholmsområdet1986Report (Other academic)
  • 355.
    Persson, Christer
    et al.
    SMHI, Research Department, Air quality.
    Wern, Lennart
    SMHI, Core Services.
    Luftvårdsstudie avseende industrikombinatet i Nynäshamn - depositionsberäkningar av koldamm1985Report (Other academic)
  • 356.
    Persson, Christer
    et al.
    SMHI, Research Department, Air quality.
    Wern, Lennart
    SMHI, Core Services.
    Spridnings- och depositionsberäkningar för avfalls- förbränningsanläggningar i Sofielund och Högdalen1985Report (Other academic)
  • 357.
    Persson, Christer
    et al.
    SMHI, Research Department, Air quality.
    Wern, Lennart
    SMHI, Core Services.
    Spridnings- och depositionsberäkningar för avfallsförbränningsanläggning i Högdalen1985Report (Other academic)
  • 358.
    Persson, Christer
    et al.
    SMHI, Research Department, Air quality.
    Wern, Lennart
    SMHI, Core Services.
    Spridnings- och depositionsberäkningar för avfallsförbränningsanläggning i Sofielund1985Report (Other academic)
  • 359.
    Persson, Gunn
    et al.
    SMHI, Professional Services.
    Asp, Magnus
    SMHI, Professional Services.
    Berggreen-Clausen, Steve
    SMHI, Professional Services.
    Berglöv, Gitte
    SMHI, Professional Services.
    Björck, Emil
    SMHI, Professional Services.
    Axén Mårtensson, Jenny
    SMHI, Core Services.
    Ohlsson, Alexandra
    SMHI, Professional Services.
    Persson, Håkan
    SMHI, Professional Services.
    Sjökvist, Elin
    SMHI, Professional Services.
    Framtidsklimat i Gotlands län - enligt RCP-scenarier2015Report (Other academic)
    Abstract [en]

    The report describes todays and future climate in Gotland County based on observations and climate modelling. Regional modelled RCP4.5 and RCP8.5 scenarios have been further downscaled to 4×4 km2 resolution. The results are presented as meteorological and hydrological indices based on statistically processed model data.

  • 360.
    Persson, Gunn
    et al.
    SMHI, Professional Services.
    Asp, Magnus
    SMHI, Professional Services.
    Berggreen-Clausen, Steve
    SMHI, Professional Services.
    Berglöv, Gitte
    SMHI, Professional Services.
    Björck, Emil
    SMHI, Professional Services.
    Axén Mårtensson, Jenny
    SMHI, Core Services.
    Ohlsson, Alexandra
    SMHI, Professional Services.
    Persson, Håkan
    SMHI, Professional Services.
    Sjökvist, Elin
    SMHI, Professional Services.
    Framtidsklimat i Hallands län - enligt RCP-scenarier2015Report (Other academic)
    Abstract [en]

    The report describes todays and future climate in Halland County based on observations and climate modelling. Regional modelled RCP4.5 and RCP8.5 scenarios have been further downscaled to 4×4 km2 resolution. The results are presented as meteorological and hydrological indices based on statistically processed model data.

  • 361.
    Persson, Gunn
    et al.
    SMHI, Professional Services.
    Asp, Magnus
    SMHI, Professional Services.
    Berggreen-Clausen, Steve
    SMHI, Professional Services.
    Berglöv, Gitte
    SMHI, Professional Services.
    Björck, Emil
    SMHI, Professional Services.
    Axén Mårtensson, Jenny
    SMHI, Core Services.
    Ohlsson, Alexandra
    SMHI, Professional Services.
    Persson, Håkan
    SMHI, Professional Services.
    Sjökvist, Elin
    SMHI, Professional Services.
    Framtidsklimat i Kalmar län - enligt RCP-scenarier2015Report (Other academic)
    Abstract [en]

    The report describes todays and future climate in Kalmar County based on observations and climate modelling. Regional modelled RCP4.5 and RCP8.5 scenarios have been further downscaled to 4×4 km2 resolution. The results are presented as meteorological and hydrological indices based on statistically processed model data.

  • 362.
    Persson, Gunn
    et al.
    SMHI, Professional Services.
    Asp, Magnus
    SMHI, Professional Services.
    Berggreen-Clausen, Steve
    SMHI, Professional Services.
    Berglöv, Gitte
    SMHI, Professional Services.
    Björck, Emil
    SMHI, Professional Services.
    Axén Mårtensson, Jenny
    SMHI, Core Services.
    Ohlsson, Alexandra
    SMHI, Professional Services.
    Persson, Håkan
    SMHI, Professional Services.
    Sjökvist, Elin
    SMHI, Professional Services.
    Framtidsklimat i Örebro län - enligt RCP-scenarier2015Report (Other academic)
    Abstract [en]

    The report describes todays and future climate in Örebro County based on observations and climate modelling. Regional modelled RCP4.5 and RCP8.5 scenarios have been further downscaled to 4×4 km2 resolution. The results are presented as meteorological and hydrological indices based on statistically processed model data.

  • 363.
    Persson, Gunn
    et al.
    SMHI, Professional Services.
    Hellström, Sara-Sofia
    SMHI, Core Services.
    Dyrestam, Karin
    Eklund, Dan
    Gyllander, Anders
    SMHI, Core Services.
    Hallberg, Kristoffer
    SMHI, Professional Services.
    Johnell, Anna
    SMHI, Professional Services.
    Tahsin, Yacob
    SMHI.
    Wingqvist, Else-Marie
    SMHI. SMHI.
    Detaljerad översvämningskartering av nedre Torneälven2011Report (Other academic)
    Abstract [en]

    Flood maps for return periods 100-years and 250-years together with a calculated highest flow have been produced for the lower part of the River Torne. The work was made within the Interreg IV A Nord Project “Detailed flood mapping of the lower part of River Torne”. Flows with return periods 100-years and 250-years were calculated statistically based on observations. The calculated highest flow was modeled with the hydrological HBV-model according to the Swedish design flood guidelines (Flood Design Category I). A hydraulic model was built to calculate water levels along the river at the different flow levels. The model was based on height data from laser scanning and river bottom data from sounding. The data sampling was made in cooperation between Swedish and Finnish authorities within the project. The flood zones were projected on background map data from the national land services in Finland and Sweden. The area was divided in nine parts and mapped with scaling 1: 75 000. The maps are available at www.smhi.se in original size and collected in appendix (bilaga 1) in a compressed form. SMHI sounded half of the investigated river length. SMHI was responsible for and performed the hydraulic modeling, flow calculations and production of flood zones and maps.

  • 364. Petersen, W.
    et al.
    Colijn, F.
    Gorringe, Patrick
    SMHI, Core Services.
    Kaitala, S.
    Karlson, Bengt
    SMHI, Research Department, Oceanography.
    King, A.
    Lips, U.
    Ntoumas, M.
    Seppälä, J.
    Sørensen, K.
    Petihakis, G.
    De La Villéon, L.P.
    Wehde, H.
    FERRYBOXES WITHIN EUROPE: STATE-OF-THE-ART AND INTEGRATION IN THE EUROPEAN OCEAN OBSERVATION SYSTEM (EOOS)2017In: OPERATIONAL OCEANOGRAPHY: Serving Sustainable Marine Development / [ed] Erik Buch, Vicente Fernández, Dina Eparkhina, Patrick Gorringe and Glenn Nolan, EuroGOOS. Brussels, Belgium , 2017, p. 63-70Conference paper (Other academic)
    Abstract [en]

    The development and use of FerryBox systems as a cost-effective instrument for continuous observations of the marine environment has been well established since more than 15 years. The systems have evolved to maturity and are since widely used around the coastal ocean of Europe. The availability of newly developed sensors allows the extension of FerryBox measurements to more biogeochemical parameters which are of interest for the requirements of the Marine Strategy Framework Directive (MSFD). The FerryBox community initially formed from the partners of an EU funded FerryBox project provides mutual exchange of experience and is now organized within EuroGOOS as a so called FerryBox Task Team (www.ferrybox.org). Within the EU funded infrastructure projects JERICO and JERICO-NEXT the technical harmonization as well as the developing of best practise guides for FerryBox systems have been a step further to high quality environmental data products. Within JERICO-NEXT it has been decided to build up a common FerryBox database and data portal in order to make the FerryBox data more available and visible. Furthermore this database will be function as a close link to the Copernicus Marine Environmental Monitoring Services (CMEMS) and the EMODnet portal.

  • 365. Petkov, Boyan H.
    et al.
    Vitale, Vito
    Tomasi, Claudio
    Siani, Anna Maria
    Seckmeyer, Gunther
    Webb, Ann R.
    Smedley, Andrew R. D.
    Casale, Giuseppe Rocco
    Werner, Rolf
    Lanconelli, Christian
    Mazzola, Mauro
    Lupi, Angelo
    Busetto, Maurizio
    Diemoz, Henri
    Goutail, Florence
    Koehler, Ulf
    Mendeva, Bogdana D.
    Josefsson, Weine
    SMHI, Core Services.
    Moore, David
    Lopez Bartolome, Maria
    Moreta Gonzalez, Juan Ramon
    Misaga, Oliver
    Dahlback, Arne
    Toth, Zoltan
    Varghese, Saji
    De Backer, Hugo
    Stuebi, Rene
    Vanicek, Karel
    Response of the ozone column over Europe to the 2011 Arctic ozone depletion event according to ground-based observations and assessment of the consequent variations in surface UV irradiance2014In: Atmospheric Environment, ISSN 1352-2310, E-ISSN 1873-2844, Vol. 85, p. 169-178Article in journal (Refereed)
    Abstract [en]

    The strong ozone depletion event that occurred in Arctic during spring 2011 was found to cause appreciable reduction in the ozone column (OC) in Europe, even at lower latitudes. The features of this episode have been analysed using the data recorded at 34 ground-based stations located in the European area and compared with the similar events in 2000 and 2005. The results provided evidence that OC as far south as 40 degrees N latitude was considerably influenced by the Arctic ozone loss in spring 2011. The reduction of OC at the northernmost sites was about 40% with respect to the mean value calculated over the previous six-year period, while a similar decrease at the southern extreme ranged between 15 and 18%, and were delayed by nearly two weeks compared to the Arctic region. The ozone distributions reconstructed for the West Europe sector show that the decline of OC lasted from late March to late April 2011. The echo of the Arctic ozone depletion on mid-latitude UV irradiance has been analysed trough model computations that show an increase of the midday erythemal dose by 3-4 SED (1 SED = 100 J m(-2)) that was slightly higher than at polar regions. On the other hand it was assessed that the biosystems in the northernmost regions were a subject of about 4 times higher UV stress than those at mid-latitudes. Despite indications of an OC recovery, the event examined here shows that the issue of ozone depletion episodes cannot be belittled. (C) 2013 Elsevier Ltd. All rights reserved.

  • 366.
    Pettersson, Ola
    SMHI, Core Services.
    Vattenbalans för fältforskningsområden2009Report (Other academic)
    Abstract [en]

    FFO isa program for hydrological and hydrochemical measurements in small watercourses.There are 20 research basins, of which SMHI is responsible for 19, connected to the FFOprograrn.In 17 of these research basins the measurements were discontinued in 1995.The water balancc (precipitation, runoff and evapotranspiration) of l 9 research basins havebeen calculated in mm for cach hydrologic year (1 Scpt.-31 Oct.) in the period 1985-J 994.Annual means and standard deviations have been calculated, and comparisons with thereference normals for the period 1961-1990 have been made. The areal precipi tation for theresearch basins during the period 1985-1994 coincided well with the correspondingprecipitation of the reference normals for the period 196 1- 1990. A differcnce of 4% in meanprecipitation amount has been confirmed, which shows that the period 1985-1994 was sJightlyrainier than the reference normal period. The nmoff was approximately at the same leve] asearlier examinations have shown, except for some research basins where leakage or problemswith the determination of the water divide is suspected. The evapotranspiration component,which has been calculated as the difference between precipitation and rnnoff, shows a goodcorrespondence between the periods. This is assurning that the net change in storage can beneglected for a 10-year period.

  • 367. Pierson, Donald C.
    et al.
    Kratzer, Susanne
    Strombeck, Niklas
    Håkansson, Bertil
    SMHI, Core Services.
    Relationship between the attenuation of downwelling irradiance at 490 nm with the attenuation of PAR (400 nm-700 nm) in the Baltic Sea2008In: Remote Sensing of Environment, ISSN 0034-4257, E-ISSN 1879-0704, Vol. 112, no 3, p. 668-680Article in journal (Refereed)
    Abstract [en]

    The vertical attenuation coefficient of diffuse downwelling irradiance at 490 nm (K-d 490) is a parameter that we routinely derive from SeaWiFS images of the Baltic Sea. Here, through model simulations, we examine the relationship between Kd(490), and the vertical attenuation coefficient of PAR (Kd PAR), as this later coefficient determines the light available for aquatic photosynthesis. A simple semi-analytical model is used to predict Kd(490) and Kd(PAR), as a function of the concentrations of chlorophyll, colored dissolved organic material (CDOM), suspended inorganic, and suspended organic particulate material. A series of model simulations based on variations in these optically significant constituents over a range realistic for the Baltic Sea, are used to define the relationship between the two attenuation coefficients. K-d(PAR) = 0.6677K(d)(490)(0.6763). This relationship was verified, using data collected independently from the data set used to derive model coefficients, and appears robust when applied to the Baltic Sea. Comparison to other studies and model sensitivity analyses suggest that the relationship will be dependent on relatively large regional variations in CDOM absorption. A relationship between K-d(490) and Secchi disk depth was also developed and verified. This relationship while useful was more uncertain. The uncertainty was related to a greater influence of scattering on Secchi disk depth estimates and the corresponding parameterization of scattering in our model. (C) 2007 Elsevier Inc. All rights reserved.

  • 368. Raschke, E
    et al.
    Meywerk, J
    Warrach, K
    Andrae, Ulf
    SMHI, Research Department, Meteorology.
    Bergström, Sten
    SMHI, Research Department, Hydrology.
    Beyrich, F
    Bosveld, F
    Bumke, K
    Fortelius, C
    Graham, Phil
    SMHI, Research Department, Climate research - Rossby Centre.
    Gryning, S E
    Halldin, S
    Hasse, L
    Heikinheimo, M
    Isemer, H J
    Jacob, D
    SMHI.
    Jauja, I
    Karlsson, Karl-Göran
    SMHI, Research Department, Atmospheric remote sensing.
    Keevallik, S
    Koistinen, J
    van Lammeren, A
    Lass, U
    Launianen, J
    Lehmann, A
    Liljebladh, B
    Lobmeyr, M
    Matthaus, W
    Mengelkamp, T
    Michelson, Daniel
    SMHI, Core Services.
    Napiorkowski, J
    Omstedt, Anders
    SMHI, Research Department, Oceanography.
    Piechura, J
    Rockel, B
    Rubel, F
    Ruprecht, E
    Smedman, A S
    Stigebrandt, A
    The Baltic Sea Experiment (BALTEX): A European contribution to the investigation of the energy and water cycle over a large drainage basin2001In: Bulletin of The American Meteorological Society - (BAMS), ISSN 0003-0007, E-ISSN 1520-0477, Vol. 82, no 11, p. 2389-2413Article, review/survey (Refereed)
    Abstract [en]

    The Baltic Sea Experiment (BALTEX) is one of the five continental-scale experiments of the Global Energy and Water Cycle Experiment (GEWEX). More than 50 research groups from 14 European countries are participating in this project to measure and model the energy and water cycle over the large drainage basin of the Baltic Sea in northern Europe. BALTEX aims to provide a better understanding of the processes of the climate system and to improve and to validate the water cycle in regional numerical models for weather forecasting and climate studies. A major effort is undertaken to couple interactively the atmosphere with the vegetated continental surfaces and the Baltic Sea including its sea ice. The intensive observational and modeling phase BRIDGE, which is a contribution to the Coordinated Enhanced Observing Period of GEWEX, will provide enhanced datasets for the period October 1999-February 2002 to validate numerical models and satellite products. Major achievements have been obtained in an improved understanding of related exchange processes. For the first time an interactive atmosphere-ocean-land surface model for the Baltic Sea was tested. This paper reports on major activities and some results.

  • 369.
    Raspaud, Martin
    et al.
    SMHI, Core Services.
    Hoese, David
    Dybbroe, Adam
    SMHI, Core Services.
    Lahtinen, Panu
    Devasthale, Abhay
    SMHI, Research Department, Atmospheric remote sensing.
    Itkin, Mikhail
    Hamann, Ulrich
    Rasmussen, Lars Orum
    Nielsen, Esben Stigard
    Leppelt, Thomas
    Maul, Alexander
    Kliche, Christian
    Thorsteinsson, Hrobjartur
    PyTroll: An Open-Source, Community-Driven Python Framework to Process Earth Observation Satellite Data2018In: Bulletin of The American Meteorological Society - (BAMS), ISSN 0003-0007, E-ISSN 1520-0477, Vol. 99, no 7, p. 1329-1336Article in journal (Refereed)
  • 370. Riihela, Aku
    et al.
    Carlund, Thomas
    SMHI, Core Services.
    Trentmann, Joerg
    Mueller, Richard
    Lindfors, Anders V.
    Validation of CM SAF Surface Solar Radiation Datasets over Finland and Sweden2015In: Remote Sensing, ISSN 2072-4292, E-ISSN 2072-4292, Vol. 7, no 6, p. 6663-6682Article in journal (Refereed)
    Abstract [en]

    Accurate determination of the amount of incoming solar radiation at Earth's surface is important for both climate studies and solar power applications. Satellite-based datasets of solar radiation offer wide spatial and temporal coverage, but careful validation of their quality is a necessary prerequisite for reliable utilization. Here we study the retrieval quality of one polar-orbiting satellite-based dataset (CLARA-A1) and one geostationary satellite-based dataset (SARAH), using in situ observations of solar radiation from the Finnish and Swedish meteorological measurement networks as reference. Our focus is on determining dataset quality over high latitudes as well as evaluating daily mean retrievals, both of which are aspects that have drawn little focus in previous studies. We find that both datasets are generally capable of retrieving the levels and seasonal cycles of solar radiation in Finland and Sweden well, with some limitations. SARAH exhibits a slight negative bias and increased retrieval uncertainty near the coverage edge, but in turn offers better precision (less scatter) in the daily mean retrievals owing to the high sampling rate of geostationary imaging.

  • 371.
    Rummukainen, Markku
    SMHI, Core Services.
    State-of-the-art with regional climate models2010In: Wiley Interdisciplinary Reviews: Climate Change, ISSN 1757-7780, E-ISSN 1757-7799, Vol. 1, no 1, p. 82-96Article, review/survey (Refereed)
    Abstract [en]

    Regional climate models are used by a large number of groups, for more or less all regions of the world. Regional climate models are complementary to global climate models. A typical use of regional climate models is to add further detail to global climate analyses or simulations, or to study climate processes in more detail than global models allow. The relationship between global and regional climate models is much akin to that of global and regional weather forecasting models. Over the past 20 years, the development of regional climate models has led to increased resolution, longer model runs, and steps towards regional climate system models. During recent years, community efforts have started to emerge in earnest, which can be expected to further advance the state-of-the-art in regional climate modeling. Applications of regional climate models span both the past and possible future climates, facilitating climate impact studies, information and support to climate policy, and adaptation. (C) 2010 John Wiley & Sons, Ltd. WIREs Clim Change 2010 1 82-96

  • 372.
    Rummukainen, Markku
    et al.
    SMHI, Core Services.
    Rockel, Burkhardt
    Bärring, Lars
    SMHI, Research Department, Climate research - Rossby Centre.
    Christensen, Jens Hesselbjerg
    Reckermann, Marcus
    Twenty-First-Century Challenges in Regional Climate Modeling2015In: Bulletin of The American Meteorological Society - (BAMS), ISSN 0003-0007, E-ISSN 1520-0477, Vol. 96, no 8, p. ES135-ES138Article in journal (Refereed)
  • 373.
    Rutgersson, Anna
    et al.
    SMHI, Research Department, Climate research - Rossby Centre.
    Bumke, K
    Clemens, M
    Foltescu, Valentin
    SMHI.
    Lindau, R
    Michelson, Daniel
    SMHI, Core Services.
    Omstedt, Anders
    SMHI, Research Department, Oceanography.
    Precipitation estimates over the Baltic Sea: Present state of the art2001In: Nordic Hydrology, ISSN 0029-1277, E-ISSN 1996-9694, Vol. 32, no 4-5, p. 285-314Article in journal (Refereed)
    Abstract [en]

    Precipitation is one of the main components in the water balance, and probably the component determined with the greatest uncertainties. In the present paper we focus on precipitation (mainly rain) over the Baltic Sea as a part of the BAL-TEX project to examine the present state of the art concerning different precipitation estimates over that area. Several methods are used, with the focus on 1) interpolation of available synoptic stations; 2) a mesoscale analysis system including synoptic, automatic, and climate stations, as well as weather radar and an atmospheric model; and 3) measurements performed on ships. The investigated time scales are monthly and yearly and also some long-term considerations are discussed. The comparison shows that the differences between most of the estimates, when averaged over an extended period and a larger area, are in the order of 10-20%, which is in the same range as the correction of the synoptic gauge measurements due to wind and evaporation losses. In all data sets using gauge data it is important to include corrections for high winds. To improve the structure of precipitation over sea more focus is to be put on the use of radar data and combinations of radar data and other data. Interpolation methods that do not consider orographic effects must treat areas with large horizontal precipitation gradients with care. Due to the large variability in precipitation in time and space, it is important to use long time periods for climate estimates of precipitation. Ship measurements are a valuable contribution to precipitation information over sea, especially for seasonal and annual time scales.

  • 374.
    Sahlberg, Jörgen
    et al.
    SMHI, Professional Services.
    Marmefelt, Eleonor
    SMHI, Professional Services.
    Brandt, Maja
    SMHI, Core Services.
    Hjerdt, Niclas
    SMHI, Core Services.
    Lundholm, Karen
    SMHI.
    HOME Vatten i Norra Östersjöns vattendistrikt: Integrerat modellsystem för vattenkvalitetsberäkningar2008Report (Other academic)
    Abstract [sv]

    SMHI har utvecklat ett interaktivt modellsystem för vattenkvalitetberäkningar i mark, sjöar, vattendrag och kustvatten, HOME Vatten. I detta uppdrag har HOME Vatten implementerats i Norra Östersjöns vattendistrikt. De ingående modellerna i HOME Vatten är HBV NP (PLC5- uppsättningen) modellen för mark, sjöar och vattendrag samt Kustzonsmodellen för kustvattnen. Atmosfärsdepositionen både på land och i kustområdet har beräknats av den atmosfärskemiska MATCH-modellen.HOME Vatten har utvecklats för att vara ett verktyg i svensk vattenförvaltning med speciellt fokus på EUs ramdirektiv för vatten.Modelluppsättningarna har validerats mot tillgängliga mätdata, och visar en god överrensstämmelse med data.

  • 375.
    Sahlberg, Jörgen
    et al.
    SMHI, Professional Services.
    Olsson, Håkan
    SMHI, Core Services.
    Kustzonsmodell för norra Östergötlands skärgård2001Report (Other academic)
  • 376.
    Sanner, Håkan
    et al.
    SMHI, Core Services.
    Harlin, Joakim
    SMHI.
    Persson, Magnus
    SMHI.
    Application of the HBV model to the Upper Indus River for inflow forecasting to the Tarbela dam1994Report (Other academic)
    Abstract [en]

    This report describes the HBV model application for inflow forecasting on a daily time step to the Tarbela dam in the Indus River. The model application forms part of the new Tarbela control center for Pakistan's Water and Power Development Authority (W APDA). The new control system will be an ABB S.P.I.D.E.R. SCADA system, delivered on a turnkey basis by ABB Network  Control of Sweden. SMHI have as subconsultants to the ABB Network Control been responsible for the set up, calibration, training and delivery of the inflow forecasting system based on the HBV model.

  • 377.
    Scheirer, Ronald
    et al.
    SMHI, Research Department, Atmospheric remote sensing.
    Dybbroe, Adam
    SMHI, Core Services.
    Raspaud, Martin
    SMHI, Core Services.
    A General Approach to Enhance Short Wave Satellite Imagery by Removing Background Atmospheric Effects2018In: Remote Sensing, ISSN 2072-4292, E-ISSN 2072-4292, Vol. 10, no 4, article id 560Article in journal (Refereed)
  • 378. Schmalwieser, Alois W.
    et al.
    Grobner, Julian
    Blumthaler, Mario
    Klotz, Barbara
    De Backer, Hugo
    Bolsee, David
    Werner, Rolf
    Tomsic, Davor
    Metelka, Ladislav
    Eriksen, Paul
    Jepsen, Nis
    Aun, Margit
    Heikkila, Anu
    Duprat, Thierry
    Sandmann, Henner
    Weiss, Tilman
    Bais, Alkis
    Toth, Zoltan
    Siani, Anna-Maria
    Vaccaro, Luisa
    Diemoz, Henri
    Grifoni, Daniele
    Zipoli, Gaetano
    Lorenzetto, Giuseppe
    Petkov, Boyan H.
    di Sarra, Alcide Giorgio
    Massen, Francis
    Yousif, Charles
    Aculinin, Alexandr A.
    den Outer, Peter
    Svendby, Tove
    Dahlback, Arne
    Johnsen, Bjorn
    Biszczuk-Jakubowska, Julita
    Krzyscin, Janusz
    Henriques, Diamantino
    Chubarova, Natalia
    Kolarz, Predrag
    Mijatovic, Zoran
    Groselj, Drago
    Pribullova, Anna
    Moreta Gonzales, Juan Ramon
    Bilbao, Julia
    Vilaplana Guerrero, Jose Manuel
    Serrano, Antonio
    Andersson, Sandra
    SMHI, Core Services.
    Vuilleumier, Laurent
    Webb, Ann
    O'Hagan, John
    UV Index monitoring in Europe2017In: Photochemical and Photobiological Sciences, ISSN 1474-905X, E-ISSN 1474-9092, Vol. 16, no 9, p. 1349-1370Article in journal (Refereed)
  • 379.
    Schöld, Sofie
    et al.
    SMHI, Core Services.
    Hellström, Sverker
    SMHI, Core Services.
    Ivarsson, Cajsa-Lisa
    SMHI, Professional Services.
    Kållberg, Per
    SMHI, Research Department, Meteorology.
    Lindow, Helma
    SMHI, Core Services.
    Nerheim, Signild
    SMHI, Professional Services.
    Schimanke, Semjon
    SMHI, Research Department, Oceanography.
    Södling, Johan
    SMHI, Professional Services.
    Wern, Lennart
    SMHI, Core Services.
    Vattenståndsdynamik längs Sveriges kust2018Report (Other academic)
    Abstract [sv]

    För att skapa ett samhälle väl anpassat till dagens och framtidens havsnivåer behövs besluts- och planeringsunderlag. Skyddsåtgärder och designnivåer för kustskydd är högaktuella frågor och många aktörer är intresserade av information kring potentiella maxnivåer för vattenstånd på olika tidshorisonter. SMHI har därför analyserat de mätdataserier för havsvattenstånd som idag finns tillgängliga från stationer längs Sveriges kust. Det primära syftet var att ta fram en metod för att beräkna det högsta möjliga havsvattenståndet vid mätstationer längs Sveriges kust. Metoden beskrivs i Schöld m.fl.(2017).

    I föreliggande rapport beskrivs allmänt havsnivåer, mätdata, modeller och de resultat som erhölls från olika analyser av mätdata. Mätstationerna indelades i åtta olika kustområden inom vilka vattenståndet samvarierar. Det väder och de specifika stormbanor, som under de senaste 40 åren orsakat de högsta stormfloderna på olika platser längs den svenska kusten kartlades, och vattenståndsdynamiken vid olika mätstationer studerades.

    Kortvariga höjningar av vattenståndet undersöktes, både med avseende på kraftiga vattenståndshöjningar orsakade av passerande väderssystem och med avseende på förhöjda utgångslägen, som i sin tur kan bidra till att stormfloder blir extra höga.

    Det högsta beräknade havsvattenstånd som presenteras är de högsta möjliga stormfloder som skulle kunna inträffa baserat på empiriska analyser av mätdata vid de olika stationerna. Kända extrema händelser, som ägt rum före det att vattenståndet började registreras, ingår inte eftersom de inte har kunnat kvantifieras. Framtida förändringar av medelvattenståndet orsakade av den globala klimatförändringen behandlas inte i denna rapport.

    Resultaten från studien visar att vattennivåerna i Östersjön generellt blir som högst i Bottenviken och i de södra delarna. De höga vattenstånden i större delen av Östersjön är inte lika höga som på västkusten och i Öresund. I Östersjön förefaller också utgångsläget, havsnivån före stormen, utgöra en större del av den resulterande vattenståndshöjningen. Vid flera stationer i de centrala delarna av Östersjön är havsnivån före storm i stort sett hälften av det högsta beräknade havsvattenståndet. Längs västkusten är istället de nettohöjningar som orsakas av rena stormeffekter den viktigaste stormflodskomponenten. Lokala förhållanden, till exempel om stationen är belägen vid en öppen, rak kust eller inne i en vik, påverkar hur högt vattenståndet kan förväntas bli på en viss plats.

    Analyserna visar att stormfloder skulle kunna bli omkring 20-40 cm högre än hittills observerade maximala nivåer i olika kustområden. En osäkerhetsmarginal på runt +15 cm är lämplig att addera, särskilt i de områden där tidvatten förekommer.

  • 380.
    Schöld, Sofie
    et al.
    SMHI, Core Services.
    Ivarsson, Cajsa-Lisa
    SMHI, Professional Services.
    Nerheim, Signild
    SMHI, Professional Services.
    Södling, Johan
    SMHI, Professional Services.
    Beräkning av högsta vattenstånd längs Sveriges kust2018Report (Other academic)
    Abstract [sv]

    I rapporten redovisas hur en metod framtagits för att kunna skatta de allra högsta havsvattenstånd som kan uppträda vid de mätstationer för havsvattenstånd som finns längs Sveriges kust. Metoden är generell och principerna kan därför tillämpas på mätdataserier från olika platser. För att kunna tillämpa metoden måste dock mätdataserien ha en viss minimilängd och tidsupplösning. Resultaten som tas fram är empiriska, vilket betyder att de baseras på tillgängliga mätdata.

    I analysen delades data upp i två delar; det genomsnittliga vattenståndet före en högvattenhändelse och nettohöjningen under en högvattenhändelse. Dessa delar benämns havsnivå före storm respektive nettohöjning, i enlighet med:

    stormflod = havsnivå före storm + nettohöjning

    Nivån på stormfloden är det högsta uppmätta havsvattenståndet under respektive högvattenhändelse. I analysen har även högvattenhändelser som inte förknippas med stormar inkluderats. Många av de högsta stormfloderna har inträffat när havsnivån före storm är förhöjd jämfört med medelvattenståndet, framförallt i stora delar av Östersjön. I analysen ingår samtliga högvattenhändelser från vilka det finns tillgänglig mätdata, även sådana som startat från ett lågt utgångsläge.

    I analysen indelades mätstationerna i olika kustområden och samvariationen mellan mätstationerna undersöktes. För varje enskild station, där havsvattenstånd observeras, har högsta havsnivå före storm och högsta nettohöjning framtagits. Den högsta havsnivån före storm som uppmätts inom kustområdet bedömdes gälla för alla mätstationer inom området. Det högsta beräknade havsvattenståndet definierades som kustområdets högsta havsnivå före storm plus mätstationens högsta nettohöjning.

    Tidvatteneffekten har inte beaktats särskilt, utan är i viss mån inkluderad i nettohöjningen. Denna förenkling beskrivs närmare i Schöld m fl. (2017).

    Analysen visade att:

    • samvariationen inom kustområden är mycket hög för vanligt förekommande vattenstånd.
    • högvattenhändelser förekommer oftare i vissa kustområden.
    • de högsta vattenstånden kan variera mycket, även mellan stationer inom samma kustområde.
    • havsnivån före storm är en mer betydande stormflodskomponent i Östersjön och mindre betydande i Skagerrak-Kattegatt.
    • havsnivån före storm behöver identifieras så att den inte är påverkad av själva stormhändelsen.
    • det är lämpligt att uppdatera det högsta beräknade havsvattenståndet regelbundet,särskilt efter att nya rekordhöga stormfloder inträffat.

    Vi valde att definiera havsnivån före storm som ett medelvärde över sju dygn, 48 timmar före stormflodens maximum. Metodiken avser nivåer ovanpå ett gällande medelvattenstånd. Framtida förändringar av medelvattenståndet orsakade av den globala klimatförändringen behandlas inte i denna rapport. Tillämpningen av metoden i ett framtida klimat beskrivs i Nerheim m fl. (2017).

  • 381.
    Sjöberg, Björn
    et al.
    SMHI, Core Services.
    STIGEBRANDT, A
    COMPUTATIONS OF THE GEOGRAPHICAL-DISTRIBUTION OF THE ENERGY FLUX TO MIXING PROCESSES VIA INTERNAL TIDES AND THE ASSOCIATED VERTICAL CIRCULATION IN THE OCEAN1992In: DEEP-SEA RESEARCH PART A-OCEANOGRAPHIC RESEARCH PAPERS, ISSN 0198-0149, Vol. 39, no 2A, p. 269-&Article in journal (Refereed)
    Abstract [en]

    The global flux of tidal energy to mixing processes via topographically generated internal waves is estimated utilizing gridded databases for bathymetry, vertical density stratification and barotropic tides together with a simple, local model for the generation of progressive internal tides at vertical steps in the ocean floor. Both the horizontal distribution of the energy flux to internal tides and its ocean mean are discussed. The computed oceanic mean value is 44 x 10(-4) W m-2, a factor of about 2-3 greater than previous estimates (MUNK, 1966, Deep-Sea Research, 13, 707-730; BELL. 1975, Journal of Geophysical Research, 80, 320-327). The global distribution of vertical diffusivity in the abyss is computed by assuming that topographically generated baroclinic motions dissipate locally and that the dissipation is distributed vertically according to an empirical law. Our results are linearly dependent on the flux Richardson number R(f). From the computed vertical diffusivities and the known vertical stratification we finally compute the global distribution of vertical velocities. Choosing a value of R(f) almost-equal-to 0.05 we obtain an upward vertical transport in the interior of the ocean, at the 1000 m level, of about 15 x 10(6) m3 s-1, which agrees with WARREN's (1981, in: Evolution of physical oceanography, B. A. WARREN and C. WUNSCH, editors. 6-41) estimated rate of sinking from surface waters at high latitudes. Below the 1000 m level the upward vertical transport increases and a maximum value of about 25 x 10(6) m3 s-1 is found at the 2000 m level, after which the transport decreases to about 8 x 10(6) m3 s-1 at the 4000 m level. This may be explained by the action of bottom currents. These currents entrain ambient water whereby the upward interior vertical transports tend to increase with depth. However, because of the entrainment of lighter ambient fluid the dense currents become less dense and only the most dense flows penetrate to the greatest depths.

  • 382.
    Sjökvist, Elin
    et al.
    SMHI, Professional Services.
    Abdoush, Diala
    SMHI, Core Services.
    Sommaren 2018 - en glimt av framtiden?2019Report (Other academic)
    Abstract [en]

    The weather in the summer of 2018 was extreme compared to what Sweden experienced during the 20th century. In some places, heat records were broken, and the combination of exceptional warm conditions with a deficit in precipitation caused a severe drought followed by forest fires and crop failure. Knowledge about impacts from climate change leads to the question: Will conditions like those in the summer of 2018 be average at the end of this century? This report compares different statistical measures from the summer of 2018 with by SMHI previously published climate scenarios.

  • 383.
    Sjökvist, Elin
    et al.
    SMHI, Professional Services.
    Asp, Magnus
    SMHI, Professional Services.
    Axén Mårtensson, Jenny
    SMHI, Core Services.
    Berggreen-Clausen, Steve
    SMHI, Professional Services.
    Berglöv, Gitte
    SMHI, Professional Services.
    Björck, Emil
    SMHI, Professional Services.
    Nylén, Linda
    SMHI, Professional Services.
    Ohlsson, Alexandra
    SMHI, Professional Services.
    Persson, Håkan
    SMHI, Professional Services.
    Framtidsklimat i Uppsala län - enligt RCP-scenarier2015Report (Other academic)
    Abstract [en]

    The report describes todays and future climate in Uppsala County based on observations and climate modelling. Regional modelled RCP4.5 and RCP8.5 scenarios have been further downscaled to 4×4 km2 resolution. The results are presented as meteorological and hydrological indices based on statistically processed model data.

  • 384.
    Sjökvist, Elin
    et al.
    SMHI, Professional Services.
    Axén Mårtensson, Jenny
    SMHI, Core Services.
    Dahné, Joel
    SMHI, Professional Services.
    Köplin, Nina
    SMHI.
    Björck, Emil
    SMHI, Professional Services.
    Nylén, Linda
    SMHI, Professional Services.
    Tengdelius Brunell, Johanna
    SMHI, Professional Services.
    Nordborg, Daniel
    SMHI.
    Hallberg, Kristoffer
    SMHI, Professional Services.
    Södling, Johan
    SMHI, Professional Services.
    Klimatscenarier för Sverige: Bearbetning av RCP-scenarier för meteorologiska och hydrologiska effektstudier2015Report (Other academic)
    Abstract [en]

    I studien används två RCP-scenarier, RCP4.5 som bygger på låga utsläpp, och RCP8.5 med höga utsläpp. Båda har tillämpats med 9 olika globala klimatmodeller på olika forskningsinstitut runt om i världen. De globala dataseten har bearbetats med den regionala klimatmodellen RCA4 på Rossby Centre vid SMHI. Att samtliga dataset bearbetats av endast en regional klimatmodell ger en osäkerhet i resultaten. Den regionala modellen jämfördes därför med två andra modeller och en tendens för något blötare klimatsignal i norra Sverige påvisades. Användning av andra regionala modeller för samma ensemble av globala modeller och strålningsdrivningsscenarier kan därför komma att uppvisa en något torrare klimatsignal. SMHI har tidigare utarbetat den s.k. DBS-metoden (Distribution Based Scaling) för bearbetning av klimatscenariodata för hydrologiska effektstudier. Bearbetad klimatdata från klimatmodellerna används som drivdata för hydrologisk modellering samt statistiska analyser av meteorologisk och hydrologisk klimatdata. I studien har två hydrologiska modeller använts parallellt. Varje klimatscenario har bearbetats separat men resultaten presenteras som ensembler av RCP4.5 och 8.5. Analys av årsmedeltemperatur visar på ökad temperatur för hela Sverige i framtiden, och störst ökning sker med det högintensiva scenariot RCP8.5. Skillnaden mellan referensperioden 1961-1990 och slutet av seklet är från 4 graders ökning i södra Sverige till upp mot 6 grader längst i norr. RCP4.5, strålningsdrivningsscenariot som inkluderar utsläppsbegränsningar, visar generellt 2 grader lägre uppvärmning. Nederbörden väntas öka i framtida klimat, RCP4.5 visar på 10-30% ökning och RCP8.5 15-40% ökning. Ökningen är störst i norra Sverige. Medeltillrinningen väntas öka i hela landet utom i sydöstra Sverige, där det sker en minskning i tillrinningen. Störst ökning sker i landets norra delar. RCP8.5 ger det mest extrema resultatet både där tillrinningen ökar och där den minskar. Extrema tillrinningar, 100-årsflöden, väntas öka i älvar i södra Sverige mot slutet av seklet. I nordliga älvar sker en oväsentlig ökning eller till och med en minskning av 100-årsflödets storlek. Arbetet med nedskalning av RCP-scenarier har resulterat i en gedigen databas med meteorologiska och hydrologiska klimatindex. Syftet med databasen är fortsatta studier inom framtida klimat på läns- och kommunnivå. För sådana studier är det viktigt att ha kunskaper om osäkerheten i resultaten, vilka beskrivs i denna rapport.

  • 385.
    Sjökvist, Elin
    et al.
    SMHI, Professional Services.
    Persson, Gunn
    SMHI, Professional Services.
    Axén Mårtensson, Jenny
    SMHI, Core Services.
    Asp, Magnus
    SMHI, Professional Services.
    Berggreen-Clausen, Steve
    SMHI, Professional Services.
    Berglöv, Gitte
    SMHI, Professional Services.
    Nylén, Linda
    SMHI, Professional Services.
    Ohlsson, Alexandra
    SMHI, Professional Services.
    Persson, Håkan
    SMHI, Professional Services.
    Framtidsklimat i Dalarnas län - enligt RCP-scenarier2015Report (Other academic)
    Abstract [en]

    The report describes todays and future climate in Dalarna County based on observations and climate modelling. Regional modelled RCP4.5 and RCP8.5 scenarios have been further downscaled to 4×4 km2 resolution. The results are presented as meteorological and hydrological indices based on statistically processed model data.

  • 386.
    Stensen, Katarina
    et al.
    SMHI, Core Services.
    Krunegård, Aino
    SMHI, Core Services.
    Rasmusson, Kristina
    SMHI, Research Department, Oceanography.
    Matti, Bettina
    SMHI, Core Services.
    Hjerdt, Niclas
    SMHI, Core Services.
    Sveriges vattentillgång utifrån perspektivet vattenbrist och torka: – Delrapport 1 i regeringsuppdrag om åtgärder för att motverka vattenbrist i ytvattentäkter.2019Report (Other academic)
    Abstract [en]

    In this report, the concept of drought in Sweden as well as the causes is discussed. Thereport also discusses the spatial variability of water resources in Sweden.

    Water shortage is when the demand for water surpasses the water available. It is thereforevery much dependent on the water usage.

    Climate change causes higher temperature and a warmer Sweden thus affecting wateravailability. In general both temperature and precipitation are expected to increase inwintertime leading to more water available during winters. However, higher temperaturesduring summers cause a higher evaporation which might lead to less water available insummertime, especially in the southern parts of Sweden. The climate change will increasethe number of extreme rainfall events. The amount of rain during such short-term extremerainfall events is usually much more than the soil´s infiltration capacity thus makingfloodings more common in future. Milder winters change the snow pattern, which inparticular affect rivers in the northern part of the country.

    During the summers 2016–2018, water shortages occurred in some parts of Sweden. Thecauses of water shortages were different for different parts and different years. Howeverit made Sweden to experience some of the impacts of climate change and a warmerclimate. It was an eye opener and showed us the importance of the adaptation to thesenew circumstances.

    Many factors are involved in the water availability. They can however be summarized in3 categories:

    • Climate – temperature and precipitation for example.
    • Storage capacity – how much water an area can store
    • Water usage

    As a country, Sweden has abundant water resources and available fresh water. But watershortage might still occur. Water availability and water usage can vary a lot locally whichmight lead to water shortage in some regions. To cope with water shortages priorities areneeded between different sectors and interests. Many stakeholders need to agree andcompromise on the usage of water.

  • 387.
    Stensen, Katarina
    et al.
    SMHI, Core Services.
    Matti, Bettina
    SMHI, Core Services.
    Rasmusson, Kristina
    SMHI, Research Department, Oceanography.
    Hjerdt, Niclas
    SMHI, Core Services.
    Modellstudie för att undersöka åtgärdersom påverkar lågflöden: – Delrapport 2 i regeringsuppdrag om åtgärder för att motverkavattenbrist i ytvattentäkter.2019Report (Other academic)
    Abstract [en]

    In 2018 the Swedish Meteorological and Hydrological Institute, SMHI was assigned toperform a study of measures to prevent water scarcity in surface water resources. Thework is ongoing and has been performed stepwise. This is the second report produced sofar. The report presents the results from a pre-study that was performed to evaluate theeffect of different measures on low flows and their potential to prevent water scarcity insurface water resources. The aim of the model study was to build a knowledge basis fordeveloping a tool that can be used to prevent water scarcity in surface water resources.Through the tool, municipalities and other actors in the water sector will be able tosimulate water availability in a catchment area independently.

    The weather has the largest impact on water availability, but there are different measuresthat can prevent water scarcity in surface water resources. The measures are mostlypreventative but some can be used in scarcity situations as well.

    The most effective measure is to use the water storage capacity in lakes and to regulatethem wisely. Obviously, this requires that there are lakes to regulate. In the southern partsof Sweden water availability is often good in wintertime while water scarcity occursduring summertime and at the beginning of fall. Through lake regulation, water can bestored in periods with significant water availability and used in periods when water isneeded. It is common to regulate lakes for hydropower production, but some lakes areregulated for water supply as well. SMHI regards this as an important aspect to considerin areas that are in risk for water scarcity since many permissions for water regulation aregoing to be reconsidered now.

    Measures on ditch, drainage and other watercourses can have a local effect, but it is notlarge enough to affect the low flows on a larger scale. Restoration of wetlands has as wellmostly a local effect since very large areas are required to impact on surface waterresources on a larger scale.

    In areas with significant water extractions, the low flow is affected if these are changed.Often, knowledge on water extraction still is inadequate and it is difficult to exactlycalculate the effect if water extractions are changed. It is also complicated to restrictwater extractions. Measures such as establishing water ponds for irrigation might havepotential provided they are filled during periods of good water availability. The effect ofextractions will then decrease during low flow periods.

    The ongoing work to prevent water scarcity in surface water resources will focus ondeveloping methods for sustainable water management. It is evident that the work withwater resources planning needs to be performed mutually between sectors in a catchmentarea. The tool that will be developed within this project will contribute to that this workcan be performed in a sustainable way.

  • 388.
    Stensen, Katarina
    et al.
    SMHI, Core Services.
    Tengdelius Brunell, Johanna
    SMHI, Professional Services.
    Sjökvist, Elin
    SMHI, Professional Services.
    Andersson, Elinor
    SMHI, Core Services.
    Eklund, Anna
    SMHI, Core Services.
    Vattentemperaturer och is i Mälaren Beräkningar för dagens och framtidens klimatförhållanden2017Report (Other academic)
    Abstract [sv]

    Denna rapport presenterar hur vattentemperatur och is beräknas förändras i Mälaren tillmitten av seklet och fram till 2100 på grund av den globala uppvärmningen.Beräkningarna är gjorda med en sjömodell där Mälaren är uppdelad i två bassänger. Dekallas västra Mälaren och östra Mälaren.De tydligaste förändringarna i Mälaren i ett framtida klimat beräknas bli högrevattentemperaturer både på ytan och på botten samt kortare period med is. Iberäkningarna har två framtidsscenarier använts, vilka baseras på mängden växthusgaser iatmosfären. I det högre scenariot, vilket motsvarar fortsatta utsläpp med dagensutsläppsnivåer, ökar vattentemperaturen mer jämfört med scenariot där utsläppen avväxthusgaser är begränsade.Sammanfattning av resultaten för klimatscenarierna: Den årliga perioden som Mälaren är täckt med is beräknas minska med enmånad till två månader mot slutet av seklet. Ytvattnets medeltemperatur beräknas öka 1,5 till 2,5 grader för bådabassängerna. Förändringen är ungefär lika stor under hela året. Bottenvattnets medeltemperatur väntas öka mellan 1 till 2 grader i den grundarevästra bassängen och 0,5 till 1,5 grader i den djupare östra bassängen.Förändringen är ungefär lika stor under hela året. Maxtemperaturen ökar något mer än medeltemperaturen för både ytvatten ochbottenvatten. Den period som ytvattnets dygnsmedeltemperatur är över 20 grader, ökar medcirka en månad upp till en och en halv månad.Medeltemperaturen och maxtemperaturen för dagens klimat är beräknad utifråntidsperioden 1997-2015 och utifrån 2032-2050 och 2080-2098 för ett framtida klimat.Maxtemperaturen är det högsta värdet som beräknas uppnås under perioden.

  • 389.
    Stensen, Katarina
    et al.
    SMHI, Core Services.
    Tengdelius Brunell, Johanna
    SMHI, Professional Services.
    Sjökvist, Elin
    SMHI, Professional Services.
    Andersson, Elinor
    SMHI, Core Services.
    Eklund, Anna
    SMHI, Core Services.
    Vattentemperaturer och is i Mälaren Beräkningar för dagens och framtidens klimatförhållanden2018Report (Other academic)
  • 390.
    Strombäck, Lena
    et al.
    SMHI, Research Department, Hydrology.
    Hjerdt, Niclas
    SMHI, Core Services.
    Eriksson Bram, Lena
    SMHI, Core Services.
    Lewau, Per
    SMHI.
    Vattenwebb: A Transparent Service to Support Decision Makers in Achieving Improved Water Status2013In: ISESS 2013, IFIP AICT 413: Information Systems and Applications / [ed] J. Hřebíček et al, IFIP International Federation for Information Processing , 2013, p. 669-678Conference paper (Refereed)
    Abstract [en]

    The vattenwebb.smhi.se service provides simulated as well as measured data on water flow and water quality for Sweden. The available data is used by the water authorities and decision makers in Sweden. The development of the site has been driven by the needs of the users and resulting in a site that is very appreciated by its users. An important aim in the development has been to make the data transparent for the end users, i.e. to explain the model assumptions and data quality in a way that is easy accessible. Therefore the site contains explanations about the model setup, how this data has been computed and information about the performance of the model. In this paper we will describe the service and its features with an emphasis on features used for achieving transparency

  • 391.
    Sundby, Mikael
    et al.
    SMHI.
    Lidén, Rikard
    SMHI, Research Department, Hydrology.
    Sjödin, Nils
    SMHI, Core Services.
    Rodriguez, Helmer
    Aranibar, Enrique
    ENDE Empresa Nacional de Electricidad.
    Hydrometeorological Monitoring and Modelling for Water Resources Development and Hydropower Optimisation in Bolivia1995Report (Other academic)
  • 392. Svensson, Ola
    et al.
    Grans, Johanna
    Celander, Malin C.
    Havenhand, Jonathan
    Leder, Erica H.
    Lindstrom, Kai
    Schöld, Sofie
    SMHI, Core Services.
    van Oosterhout, Cock
    Kvarnemo, Charlotta
    Immigrant reproductive dysfunction facilitates ecological speciation2017In: Evolution, ISSN 0014-3820, E-ISSN 1558-5646, Vol. 71, no 10, p. 2510-2521Article in journal (Refereed)
  • 393. Tam, Jamie C.
    et al.
    Link, Jason S.
    Rossberg, Axel G.
    Rogers, Stuart I.
    Levin, Philip S.
    Rochet, Marie-Joelle
    Bundy, Alida
    Belgrano, Andrea
    Libralato, Simone
    Tomczak, Maciej
    van de Wolfshaar, Karen
    Pranovi, Fabio
    Gorokhova, Elena
    Large, Scott I.
    Niquil, Nathalie
    Greenstreet, Simon P. R.
    Druon, Jean-Noel
    Lesutiene, Jurate
    Johansen, Marie
    SMHI, Core Services.
    Preciado, Izaskun
    Patricio, Joana
    Palialexis, Andreas
    Tett, Paul
    Johansen, Geir O.
    Houle, Jennifer
    Rindorf, Anna
    Towards ecosystem-based management: identifying operational food-web indicators for marine ecosystems2017In: ICES Journal of Marine Science, ISSN 1054-3139, E-ISSN 1095-9289, Vol. 74, no 7, p. 2040-2052Article in journal (Refereed)
  • 394. Taubald, H.
    et al.
    Tonderski, K.
    Andersson, Lotta
    SMHI, Core Services.
    Ronnberg, R.
    Ahlgren, J.
    Oxygen isotopes in phosphate as a tracer for sources and pathways of catchment P in stream water2010In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 74, no 12, p. A1030-A1030Article in journal (Other academic)
  • 395.
    Thompson, Thomas
    et al.
    SMHI.
    Udin, Ingemar
    SMHI, Core Services.
    Omstedt, Anders
    SMHI, Research Department, Oceanography.
    Sea surface temperatures in waters surrounding Sweden1974Report (Other academic)
    Abstract [en]

    One of the sub-projects within the sea ice research programme carried out at SMHI deals with the thermodynamics of the sea and the ice. In these studies the sea surface temperature plays a fundamental r ole. During the latest years considerable efforts have been made in order to obtain more temperature observations, in particular from the open sea. Various vessels have been equipped with new instruments, the collection of observations improved, the sea surface temperature distribution analyzed every second day and all information stored in digital form.

    The instruments are discribed and their specifications given in the report. Various observational methods are compared and examples of sea surface temperature analyses for the period July 1973 - July 1974  illustrating yearly variations, tendency to circulation patterns, coastal effects, up-welling etc. are given.

  • 396.
    Tiderman, Karin
    SMHI, Core Services.
    Sänkta och torrlagda sjöar: Svenskt Vattenarkiv1995Report (Other academic)
  • 397. Tiselius, Peter
    et al.
    Belgrano, Andrea
    Andersson, Lars
    SMHI, Core Services.
    Lindahl, Odd
    Contribution to the Themed Section: Scaling from individual Plankton to marine ecosystems Primary productivity in a coastal ecosystem: a trophic perspective on a long-term time series2016In: Journal of Plankton Research, ISSN 0142-7873, E-ISSN 1464-3774, Vol. 38, no 4, p. 1092-1102Article in journal (Refereed)
  • 398. Toledano, C.
    et al.
    Cachorro, V. E.
    Gausa, M.
    Stebel, K.
    Aaltonen, V.
    Berjon, A.
    Ortiz de Galisteo, J. P.
    de Frutos, A. M.
    Bennouna, Y.
    Blindheim, S.
    Myhre, C. L.
    Zibordi, G.
    Wehrli, C.
    Kratzer, S.
    Håkansson, Bertil
    SMHI, Research Department, Oceanography.
    Carlund, Thomas
    SMHI, Core Services.
    de Leeuw, G.
    Herber, A.
    Torres, B.
    Overview of sun photometer measurements of aerosol properties in Scandinavia and Svalbard2012In: Atmospheric Environment, ISSN 1352-2310, E-ISSN 1873-2844, Vol. 52, p. 18-28Article in journal (Refereed)
    Abstract [en]

    An overview on the data of columnar aerosol properties measured in Northern Europe is provided. Apart from the necessary data gathered in the Arctic, the knowledge of the aerosol loading in nearby areas (e.g. sub-Arctic) is of maximum interest to achieve a correct analysis of the Arctic aerosols and transport patterns. This work evaluates data from operational sites with sun photometer measurements belonging either to national or international networks (AERONET, GAW-PFR) and programs conducted in Scandinavia and Svalbard. We enumerate a list of sites, measurement type and periods together with observed aerosol properties. An evaluation and analysis of aerosol data was carried out with a review of previous results as well. Aerosol optical depth (AOD) and Angstrom exponent (AE) are the current parameters with sufficient long-term records for a first evaluation of aerosol properties. AOD (500 nm) ranges from 0.08 to 0.10 in Arctic and sub-Arctic sites (Ny-Alesund: 0.09; Andenes: 0.10; Sodankyla: 0.08), and it is somewhat higher in more populated areas in Southern Scandinavia (AOD about 0.10-0.12 at 500 nm). On the Norwegian coast, aerosols show larger mean size (AE = 1.2 at Andenes) than in Finland, with continental climate (AE = 1.5 at Sodankyla). Columnar particle size distributions and related parameters derived from inversion of sun/sky radiances were also investigated. This work makes special emphasis in the joint and collaborative effort of the various groups from different countries involved in this study. Part of the measurements presented here were involved in the IPY projects Polar-AOD and POLARCAT. (C) 2011 Elsevier Ltd. All rights reserved.

  • 399.
    Udin, Ingemar
    et al.
    SMHI, Core Services.
    Mattisson, Ingemar
    SMHI.
    Havsis- och snöinformation ur datorbearbetade satellitdata – en modellstudie1979Report (Other academic)
    Abstract [en]

    Computer programs have been developed for handling of NOAA VHRR digital data. The programs include geometric corrections, presentation of calibration data, derivation of data, variation of grey scales, different presentation forms etc. A SAAB D23 computer has been used for the computations. Line printer has mostly been used for presentation of data, but also electrostatic plotter and ink jet plotter have been used. The analogue VHRR data was digitized at the Swedish Defense Rese·arch Board. The soft ware has mainly been applied to sea ice and snow studies but also in a less degree to studies of sea surface temperature and examination of data, which was supposed to be the oil spill at platform Bravo ·in the Ekofisk area. Digital processed satellite data are more useful than photographic pictures both for sea ice and snow mapping. Quantification of snow cover and sorne ice parameters is possible, but for many purposes a multispectral data analysis is necessary in order to avoid false information. A short sea ice study with computer processed LANDSAT data has also been carried out. The soft ware used was developed at the Swedish Defense Research Board.

  • 400.
    Vedin, Haldo
    et al.
    SMHI.
    Eklund, Anna
    SMHI, Core Services.
    Alexandersson, Hans
    SMHI.
    The rainstorm and flash flood at Mount Fulufjallet in August 1997: The meteorological and hydrological situation1999In: Geografiska Annaler. Series A, Physical Geography, ISSN 0435-3676, E-ISSN 1468-0459, Vol. 81A, no 3, p. 361-368Article in journal (Refereed)
    Abstract [en]

    The flood at Mount Fulufjallet, 30-31 August 1997 was caused by the most furious rainstorm ever documented in Sweden. Private measurements on the mountain show nor less than 276 mm over 24 hours, and the distribution of severe damage suggests even higher amounts in other parts of the mountain. The precipitation was connected to a front attacking a high pressure that had been dominating the weather in Sweden for several weeks, but orographic lifting on the east-facing slopes of the mountain may partly have caused the extreme intensity. In River Fulan. one of the upper branches of River Dalalven, the discharge peaked at a diurnal mean value of 233 m(3)/s, the highest since measurements began in 1913. At the stream Tangan and the new common outlet of the streams Store and Lilla Goljan, both locations with a normal discharge of only around 1 m(3)/s, instantaneous values of approximately 300 m(3)/s have been estimated, corresponding to values close to the normal discharge at the mouth of River Dalalven on the coast of the Sea of Bothnia.

56789 351 - 400 of 442
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