Endre søk
Begrens søket
123 51 - 100 of 116
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Treff pr side
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Disputationsdatum (tidligste først)
  • Disputationsdatum (siste først)
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Disputationsdatum (tidligste først)
  • Disputationsdatum (siste først)
Merk
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 51.
    Kjellström, Erik
    et al.
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Bärring, Lars
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Gollvik, Stefan
    Meterologi.
    Hansson, Ulf
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Jones, Colin
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Samuelsson, Patrick
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Ullerstig, Anders
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Willén, Ulrika
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Wyser, Klaus
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    A 140-year simulation of European climate with the new version of the Rossby Centre regional atmospheric climate model (RCA3)2005Rapport (Annet vitenskapelig)
    Abstract [en]

    This report presents the latest version of the Rossby Centre regional atmospheric model, RCA3, with focus on model improvements since the earlier version, RCA2. The main changes in RCA3 relate to the treatment of land surface processes. Apart from the changes in land surface parameterizations several changes in the calculation of radiation, clouds, condensate and precipitation have been made. The new parameterizations hold a more realistic description of the climate system.Simulated present day climate is evaluated compared to observations. The new model version show equally good, or better, correspondence to observational climatologies as RCA2, when forced by perfect boundary conditions. Seasonal mean temperature errors are generally within ±1oC except during winter in north-western Russia where a larger positive bias is identified. Both the diurnal temperature range and the annual temperature range are found to be underestimated in the model. Precipitation biases are generally smaller than in the corresponding reanalysis data used as boundary conditions, showing the benefit of a higher horizontal resolution.The model is used for the regionalization of two transient global climate change projections for the time period 1961- 2100. The radiative forcing of the climate system is based on observed concentrations of greenhouse gases until 1990 and on the IPCC SRES B2 and A2 emissions scenarios for the remaining time period. Long-term averages as well as measures of the variability around these averages are presented for a number of variables including precipitation and near-surface temperature. It is shown that the changes in variability sometimes differ from the changes in averages. For instance, in north-eastern Europe, the mean increase in wintertime temperatures is followed by an even stronger reduction in the number of very cold days in winter. This kind of performance of the climate system implies that methods of inferring data from climate change projections to other periods than those actually simulated have to be used with care, at least when it comes to variables that are expected to change in a non-linear way. Further, these new regional climate change projections address the whole 21st century.

  • 52.
    Klein, Thomas
    et al.
    SMHI, Samhälle och säkerhet.
    Bergström, Robert
    SMHI, Forskningsavdelningen, Luftmiljö.
    Persson, Christer
    SMHI, Forskningsavdelningen, Luftmiljö.
    Parameterization of dry deposition in MATCH2002Rapport (Annet vitenskapelig)
    Abstract [en]

    The present report describes the calculation of dry deposition in the Multi scale Atmospheric Transport and Chemistry modeling system (MATCH) applied in environmental monitoring studies. For this type of applications dry deposition is parameterized by means of a resistance concept. Modeled dry deposition velocities for different surface types, a variety of meteorological conditions and several chemical species are presented. The deposition’s dependence on the individual partial resistances and their variation with the meteorological conditions are illustrated by means of time-series. The details of the resistance concept are discussed in a pedagogical way in order to both facilitate understanding and to point out different deposition paths.Sensitivity studies have been performed for the laminar sub-layer resistance of particles for which two different settings of resistance values are compared. The importance of SO2 and NO2 uptake by the stomata of plants and the deposition of SO2 to the external parts of plants have also been investigated by means of sensitivity studies. In addition, horizontal maps and monthly mean values of dry deposition velocities based on meteorological data for 1998 are presented.

  • 53.
    Klein, Thomas
    et al.
    SMHI, Samhälle och säkerhet.
    Karlsson, Per-Erik
    IVL Swedish Environmental Research Institute.
    Andersson, Stefan
    SMHI, Forskningsavdelningen, Luftmiljö.
    Engardt, Magnuz
    SMHI, Forskningsavdelningen, Luftmiljö.
    Sjöberg, Karin
    IVL Swedish Environmental Research Institute.
    Assessing and improving the Swedish forecast and information capabilities for ground-level ozone2011Rapport (Annet vitenskapelig)
    Abstract [en]

    This study aims to assess and improve the Swedish forecast and information capabilities for ground-level ozone concentrations in ambient air. The assessment is based on a set of archived results from the Swedish operational chemical transport model MATCH and Swedish in-situ measurements of ozone covering the period of May 2008 to November 2010. The evaluation comprises two major activities: The first activity is an analysis of the overall model performance using standard statistical metrics suitable for longer time series. The second evaluation activity comprises in-detail analyses of the specific ozone episodes occurring in Sweden during the study period. In addition, trajectory modelling is used to investigate the meteorological conditions and transport patterns associated with those episodes. The evaluation of the model results shows that the model scores well according to standard evaluation criteria and confirms results of other studies in that the model easily meets the data quality requirements of the EU air quality directive 2008/50/EC. However, from an operational forecasting and information perspective it would be desirable to further improve the prediction of, in particular, high-level ozone episodes. Two different activities in our study are dedicated to the task of improving the forecast and information capabilities: The first activity tests the usefulness of statistical postprocessing of model results using regression techniques. The tests show promising results although the model performance during high-level ozone episodes is not improved. A limitation of our study is the relatively small archive of model data available for calibration andevaluation. Adaptive post-processing methods have not been tested in our study. The second activity aimed to improve ozone forecasting is a high-resolution model run for the year 2010. The higher reso-lution run gives slightly better results than the coarser operational model, which can be attributed to a better resolution of the physiography and thus certain physical and chemical processes. In particular, high-resolution simulations provide a more realisticrepresentation of the spatial ozone variation which is desirable for environmental assessments with a longer time horizon. However, from the perspective of operational ozone forecasting the increase in resolution cannot correct systematic problems such as an under-prediction of ozone if the source of ozone is non-local and the long-range transboundary transport is not correctly described by the European-scale model used as boundaries. Other potential sources of error are incomplete or erroneous emissions, representativeness issues, oversimplifications in the model’s physical or chemical processes, lacking data assimilation and initialization and oversimplifiedboundary conditions. While several of these issues are already addressed in current initiatives such as the EU FP7-project MACC, it is clear that further work will be needed during the coming years. Further work should also be invested in a better exploitation of the international developments within MACC and in the establishment of operational high-resolution air quality forecasts for Sweden, using boundary values from European-scale forecasts provided by theMACC-ensemble of regional air quality models.

  • 54.
    Landelius, Tomas
    et al.
    SMHI, Forskningsavdelningen, Atmosfärisk fjärranalys.
    Josefsson, Weine
    SMHI, Forskningsavdelningen, Atmosfärisk fjärranalys.
    Persson, Thomas
    SMHI.
    A system for modelling solar radiation parameters with mesoscale spatial resolution2001Rapport (Annet vitenskapelig)
    Abstract [en]

    Today, modern analysis systems synthesise meteorological data from a number of sources, e.g.\ round based SYNOP, satellites, radar, etc., into field information which enable us to model radiation at the Earth’s surface on the mesoscale. At the Swedish Meteorological and Hydrological Institute (SMHI) we have set up a model system that produce hourly information in terms of field data with a resolution of about 22 ´ 22 km2 for a geographic area covering Scandinavia and the run off region of the Baltic sea.Presently, the model calculates fields of global-, photosynthetically active- (PAR), UV- and direct radiation based on output from a mesoscale analysis system, a high resolution limited area numerical weather prediction model (NWP), an ice model for the Baltic sea together with satellite measurements of total ozone. A spectral clear sky model lies at the heart of the model system. Its output is multiplied by a function which captures the influence of clouds and precipitation. Different cloud effect functions are applied to the different radiation components, with the exception of global- and PAR for which the same relation is assumed.Measurements from the radiation network of SMHI were used for estimation and validation purposes. A first evaluation of the model system suggests that the RMSE for hourly global radiation data is on the order of 28% and about 16% for daily values. These errors are comparable to those obtained for models purely based on synoptic observations (SYNOP) (29% and 13%) . For UV radiation the figures are similar but for the direct radiation component they are worse; 53% and 31% respectively compared to 25% and 15% for the SYNOP models. To some extent the larger errors for the direct component could be explained by its sensitivity to scale differences when model grid squares are validated against point measurements.

  • 55.
    Langner, Joakim
    et al.
    SMHI, Forskningsavdelningen, Luftmiljö.
    Bergström, Robert
    SMHI, Forskningsavdelningen, Luftmiljö.
    Plejel, Karin
    Swedish Environmental Research Institute IVL.
    European scale modeling of sulfur, oxidized nitrogen and photochemial oxidants: Model development and evaluation for the 1994 growing season1998Rapport (Annet vitenskapelig)
    Abstract [en]

    A chemical mechanism, including the relevant reactions leading to the production of ozone and other photochemical oxidants, has been implemented in the MATCH regional tracer transport/chemistry/deposition model. The aim has been to develop a model platform that can be used as a basis for a range of regional scale studies involving atmospheric chemistry, including assessment of the importance of different sources of pollutants to the levels of photochemical oxidants and air pollutant forecasting. Meteorological input data to the model were taken from archived output from the operational version of HIRLAM at SMHI. Evaluation of model calculations over Europe for a six month period in 1994 for a range of chemical components show good results considering known sources of error and uncertainties in input data and model formulation. With limited further work the system is sufficiently good to be applied for scenario studies and for regional scale air pollutant forecasts.

  • 56.
    Langner, Joakim
    et al.
    SMHI, Forskningsavdelningen, Luftmiljö.
    Persson, Christer
    SMHI, Forskningsavdelningen, Luftmiljö.
    Robertson, Lennart
    SMHI, Forskningsavdelningen, Luftmiljö.
    Ullerstig, Anders
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Air pollution Assessment Study Using the MATCH Modelling System: Application to sulfur and nitrogen compounds over Sweden 19941996Rapport (Annet vitenskapelig)
  • 57.
    Laurin, Sten
    SMHI.
    Population exposure to SO2 and NOx from different sources in Stockholm1984Rapport (Annet vitenskapelig)
  • 58.
    Liljas, Erik
    SMHI, Samhälle och säkerhet.
    Analys av moln och nederbörd genom automatisk klassning av AVHRR-data1981Rapport (Annet vitenskapelig)
  • 59.
    Lind, Petter
    et al.
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Kjellström, Erik
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Temperature and precipitation changes in Sweden; a wide range of model-based projections for the 21st century2008Rapport (Annet vitenskapelig)
    Abstract [en]

    In this report we analyze the climate change signal for Sweden in scenarios for the 21st century in a large number of coupled atmosphere-ocean general circulation models (AOGCMs), used in the fourth assessment report by the Intergovernmental Panel on Climate Change (IPCC). We focus on near-surface temperature and precipitation. The analysis includes six emission scenarios as well as multi-member runs with the AOGCMs. At the Rossby Centre, SMHI, regional climate models have been run under different emission scenarios and driven by a few AOGCMs. The results of those runs have been used as a basis in climate change, impact and adaptation assessments. Here, we evaluate results from these regional climate model runs in relation to the climate change signal of the IPCC AOGCMs. First, simulated conditions for the recent past (1961-1990) are evaluated. Generally, most AOGCMs tend to have a cold bias for Sweden, especially in winter that can be as large as 10°C. Also, the coarse resolution of the AOGCMs leads to biases in simulated precipitation, both in averages, extremes and often also in the phase of the seasonal cycle. Generally, AOGCMs overestimate precipitation in winter; biases reach 30-40% or even more. In summer, some AOGCMs overestimate precipitation while others underestimate it. Projected responses depend on season and geographical region. Largest signals are seen in winter and in northern Sweden, where the mean simulated temperature increase among the AOGCMs (and across the emissions scenarios B1, A1B and A2) is nearly 6°C by the end of the century, and precipitation increases by around 25%. In southern Sweden, corresponding values are around +4°C and +11%. In summer, the temperature increase is more moderate, which is also the case for precipitation. The regional climate signals are usually within the ranges given by the AOGCM runs, however, the regional models tends to show larger increases in winter, and smaller increases in summertime precipitation.

  • 60.
    Lundqvist, Jan-Eric
    et al.
    SMHI.
    Udin, Ingemar
    SMHI, Samhälle och säkerhet.
    Ice accretion on ships with special emphasis on Baltic conditions1977Rapport (Annet vitenskapelig)
    Abstract [sv]

    Sedan mitten av 1960-talet har nedisningsrapporter från fartyg som trafikerat Östersjön samlats in av SMHI. Rapporterna har bearbetats och samband mellan nedisning och vissa meteorologiska och oceanografiska parametrar har studerats. Undersökningen har omfattat handelsfartyg av typisk storlek för Östersjön. Rapporten visar resultaten från nedisningskampanjen. Den innehåller dessutom en allmän beskrivning, vilken omfattar faktorer som orsakar nedisning, frysprocessen etc. En del tidigare arbeten har studerats och jämförelser av resultat har gjorts. Nedisningsprognoser diskuteras och den metod som nu används vid SMHI beskrivs. Slutligen ges en del kommentarer om metoder att undvika eller minska nedisning.

  • 61.
    Lönnqvist., Olov
    SMHI.
    Congression – A fast regression technique with a great number of functions of all predictors1984Rapport (Annet vitenskapelig)
  • 62.
    Lönnqvist., Olov
    SMHI.
    Nederbördsstatistik med praktiska tillämpningar: Precipitation statistics with practical applications1981Rapport (Annet vitenskapelig)
    Abstract [en]

    Precipitation statistics for Sweden are presented in a very special way in order to serve as a planning tool in the Weather Service. Empirical Orthogonal Functions for the precipitation based on monthly normals for 643 stations, 1931-1960, are applied to two practical design problems, viz. geographical areas for weather forecasting and the network of synoptic stations. The paper also deals with maritime and continental areas of Sweden. The representativity of results obtained is judged by a sample af precipitation data for the last 100 years.A discussion is given as to the usefulness of the climatological method for the actual aoplication purposes as compared with correlation af time-series of precipiation and other weather parameters.

  • 63.
    Meier, Markus
    SMHI, Forskningsavdelningen, Oceanografi.
    The first Rossby Centre regional climate scenario for the Baltic Sea using a 3D coupled ice-ocean model2001Rapport (Annet vitenskapelig)
    Abstract [en]

    Temperature, salinity, sea ice and sea leve! in the Baltic Sea have been analyzed under different climate conditions using a 3D coupled ice-ocean mode!. As a reference, hindcast simulations for the period 1980-93 have been performed with observed three-hourly meteorological forcing fields and observed monthly river runoff. The observed Baltic Sea climate is well  reproduced by the mode!. Furthermore, two sets of 9-year time slice experiments have been performed using results of an atmospheric regional climate mode! as forcing, one representing pre-industrial climate conditions (control simulation), and the other one global waiming with a 150% increase of CO2 greenhouse gas concentration (scenario simulation). At the boundaries of the regional climate mode! results of the global atmosphere-ocean general circulation mode! HadCM2 (Hadley Centre) have been prescribed. To simulate river runoff, a large-scale hydrological mode! has been applied. As the time slices are too short to spin up initial stratification for future climate, salinity is treated as uncertainty. An extreme condition is obtained, integrating the Baltic Sea model for 100 years assuming that no salt water inflow occurs in future. The area averaged annual mean sea surface temperature change between scenario and control run is about 2.3 'C. Seasonal variability of the change is small compared to the corresponding 2 m air temperature change. The uncertainty due to unknown future initial conditions is relatively small (largest in summer with -0.5'C). The decrease of mean ice extent in the scenario compared to the control run is dramatic, from 210 • 109m2 to 82 • 109m2 (a relative change of 61 % ). However, in all years ice can still be found in the Bothnian Bay. The minimum ice extent is I 6 • 109m2 (for comparison: the area of the Bothnian Bay is about twice as !arge). The mean number of ice days decreases significantly, too. In the fast ice zone of the Bothnian Bay (Kemi) the mean ice season becomes 40 days shorter. The ice in the scenario run is thinner with less snow on top. In the·central Bothnian Bay mean maximum annual ice thickness is reduced by 25 cm from 54 to 29 cm. Mode! dependent uncertainties are discussed.

  • 64.
    Meier, Markus
    et al.
    SMHI, Forskningsavdelningen, Oceanografi.
    Andréasson, Johan
    SMHI, Affärsverksamhet.
    Broman, Barry
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Graham, Phil
    SMHI, Affärsverksamhet.
    Kjellström, Erik
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Persson, Gunn
    SMHI, Affärsverksamhet.
    Climate change scenario simulations of wind, sea level, and river discharge in the Baltic Sea and Lake Mälaren region – a dynamical downscaling approach from global to local scales2006Rapport (Annet vitenskapelig)
    Abstract [en]

    A regional climate model (RCM) and oceanographic, hydrological and digital elevation models were applied to study the impact of climate change on surface wind, sea level, river discharge, and flood prone areas in the Baltic Sea region. The RCM was driven by two global models and two emission scenarios. According to the four investigated regional scenario simulations, wind speed in winter is projected to increase between 3 and 19% as an area average over the Baltic Sea. Although extremes of the wind speed will increase about as much as the mean wind speed, sea level extremes will increase more than the mean sea level, especially along the eastern Baltic coasts. In these areas projected storm events and global average sea level rise may cause an increased risk for flooding. However, the Swedish east coast will be less affected because mainly the west wind component in winter would increase and because land uplift would compensate for increased sea levels, at least in the northern parts of the Baltic. One of the aims of the downscaling approach was to investigate the future risk of flooding in the Lake Mälaren region including Stockholm city. In Stockholm the 100-year surge is projected to change between -51 and 53 cm relative to present mean sea level suggesting that in the city the risk of flooding from the Baltic Sea is relatively small because the critical height of the jetty walls will not be exceeded. Lake Mälaren lies just to the west of Stockholm and flows directly into the Baltic Sea to the east. This study addresses also the question of how the water level in Lake Mälaren may be affected by climate change by incorporating the following three contributing components into an analysis: 1) projected changes to hydrological inflows to Lake Mälaren, 2) changes to downstream water levels in the Baltic Sea, and 3) changes in outflow regulation from the lake. The first component is analyzed using hydrological modeling. The second and third components employ the use of a lake discharge model. An important conclusion is that projected changes to hydrological inflows show a stronger impact on lake levels than projected changes in water level for the Baltic Sea. Furthermore, an identified need for increased outflow capacity from the lake for the present climate does not diminish with projections of future climate change. The tools developed in this work provide valuable inputs to planning for both present and future operations of water level in Lake Mälaren. Based on the oceanographic and hydrological scenario simulations, flood prone areas were analysed in detail for two municipalities, namely Ekerö and Stockholm. The GIS analysis of both municipalities indicates a series of affected areas. However, in case of the 100-year flood (0.65 m above the mean lake level) in present climate or even in case of the maximum probable flood (1.48 m above the mean lake level) the potential risks will be relatively low.

  • 65.
    Melgarejo, José
    SMHI.
    An analytical model of the boundary layer above sloping terrain with an application to observations in Antarctica1986Rapport (Annet vitenskapelig)
  • 66.
    Melgarejo, José
    SMHI.
    Similarity theory and resistance laws for the atmospheric boundary layer1981Rapport (Annet vitenskapelig)
  • 67.
    Meuller, Lars
    et al.
    SMHI.
    Robertson, Lennart
    SMHI, Forskningsavdelningen, Luftmiljö.
    Andersson, E.
    SMHI.
    Gustavsson, Nils
    Meterologi.
    Meso-g scale objective analysis of near surface temperature, humidity and wind, and its application in air pollution modelling1990Rapport (Annet vitenskapelig)
  • 68.
    Michelson, Daniel
    et al.
    SMHI, Forskningsavdelningen, Atmosfärisk fjärranalys.
    Andersson, Tage
    SMHI, Forskningsavdelningen.
    Koistinen, Jarmo
    Collier, Christopher G.
    Riedl, J.
    Szturc., J.
    Nielsen, A.
    Overgaard Persson, T.
    BALTEX Radar Data Centre Products and their Methodologies2000Rapport (Annet vitenskapelig)
  • 69.
    Moen, Lars
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    A multi-level quasi-geostrophic model for short range weather predictions1975Rapport (Annet vitenskapelig)
    Abstract [en]

    A quite generally formulated multilevel quasi-geostrophic medel with possibilities to include second order terms in the vorticity equation is derived. The model includes friction, topography, latent heat and sensible heat. The treatment of the variable boundary conditions, smoothing and ellipticity control is described.

  • 70.
    Nyberg, Anders
    SMHI.
    On transport of sulphur over the North Atlantic1976Rapport (Annet vitenskapelig)
    Abstract [sv]

    Svavelinnehållet i nederbörden har uppmätts på väderskepp i Nordatlanten. På grundval härav och av trajektorieberäkningar visas att betydande mängder antropogent svavel transporteras från Nordamerika mot Europa. Torrdepositionen av svavel över Atlanten på långa avstånd från källan måste vara mycket liten. Värdena på nederbördsutfallet av svavel ur luft som kommer från det azoriska högtrycksområdet är mycket låga och man kan därför säga att det naturliga svavlet i nederbörd i allmänhet högst är av storleksordningen  0 .0 mg/1.

  • 71.
    Omstedt, Anders
    SMHI, Forskningsavdelningen, Oceanografi.
    A sensitivity analysis of steady, free floating ice1980Rapport (Annet vitenskapelig)
    Abstract [sv]

    Ekvationen för stationär, friflytande is härleds och analyseras för ett grunt hav. Analysen behandlar hur noggrant den stationära, friflytande isens rörelse kan beräknas då variationer införs i ingångsparametrarna. Förutom fel på grund av icke perfekta vindar, orsakar områden med starka strömmar dålig noggrannhet. Om dessutom bottendjupet försummas i dessa områden blir noggrannheten sämre. Varierande isskrovlighet och varierande friktionshastighet medför fel som är mindre viktiga men ändock märkbara i den beräknade ishastigheten.

  • 72.
    Omstedt, Anders
    et al.
    SMHI, Forskningsavdelningen, Oceanografi.
    Sahlberg, Jörgen
    SMHI, Affärsverksamhet.
    Some results from a joint Swedish-Finnish sea ice experiment, March, 19771978Rapport (Annet vitenskapelig)
    Abstract [sv]

    Ett gemensamt svensk-finskt havsisexperiment genomfördes under mars 1977. Mätningar i atmosfären, isen och havet utfördes under sex dagar ombord på det finska forskningsfartyget Aranda som var placerad i isfältet i Bottenviken. Under två dagar utfördes även mätningar från de två svenska isbrytarna Atle och Tor. Denna rapport presenterar data och några resultat från svenska gruppen.

  • 73.
    Omstedt, Gunnar
    SMHI, Forskningsavdelningen, Luftmiljö.
    An operational air pollution model1988Rapport (Annet vitenskapelig)
    Abstract [en]

    This report describes an operational air pollution medel developed at the Swedish Meteorological and Hydrological Institut for the prediction of air pollution concentrations on a local scale. Predictions can be roade in one or several receptor points for emissions from point, area- and traffic sources. The medel is partly based on the Danish so calledOML-model (Berkowicz et al.,1985).

  • 74.
    Omstedt, Gunnar
    SMHI, Forskningsavdelningen, Luftmiljö.
    An operational air pollution model using routine meteorological data1984Rapport (Annet vitenskapelig)
  • 75.
    Omstedt, Gunnar
    SMHI, Forskningsavdelningen, Luftmiljö.
    Spridning av luftförorening från skorsten i konvektiva gränsskikt1982Rapport (Annet vitenskapelig)
  • 76.
    Omstedt, Gunnar
    et al.
    SMHI, Forskningsavdelningen, Luftmiljö.
    Szegö, Janos
    SMHI.
    Människors exponering för luftföroreningar1990Rapport (Annet vitenskapelig)
  • 77.
    Pershagen, H.
    SMHI.
    Maximisnödjup i Sverige (perioden 1905–70)1981Rapport (Annet vitenskapelig)
    Abstract [en]

    Data have been obtained from 40 selected meteorological stations.The following monthly tables have been prepared:

    A Various statistical information in cm.B The five highest and lowest values with year of occurrence.C Relative frequency.D Classification of the depth of snow.E The five mast and least severe snow-seasons for each station.F The five mast and least severe snow-seasons in certain regions.G The five mast and least severe snow-conditions divided inta regions and months with indication of year.H Maximum depth of snow at each station and <luring each of the 72 years  with indication of month.I  Various stalistical information derived from the values of table H.K Highest and lowest yearly maximum and difference in cm.L Extreme values of the depth of snow.

  • 78.
    Persson, Christer
    SMHI, Forskningsavdelningen, Luftmiljö.
    Local scale plume model for nitrogen oxides. Verification1986Rapport (Annet vitenskapelig)
  • 79.
    Persson, Christer
    et al.
    SMHI, Forskningsavdelningen, Luftmiljö.
    Funquist, Lennart
    SMHI, Forskningsavdelningen, Oceanografi.
    Local scale plume model for nitrogen oxides: Model description1984Rapport (Annet vitenskapelig)
  • 80.
    Persson, Christer
    et al.
    SMHI, Forskningsavdelningen, Luftmiljö.
    Langner, Joakim
    SMHI, Forskningsavdelningen, Luftmiljö.
    Robertson, Lennart
    SMHI, Forskningsavdelningen, Luftmiljö.
    Regional spridningsmodell för Göteborgs och Bohus, Hallands och Älvsborgs län: A mesoscale air pollution dispersion model for the Swedish west-coast region. In Swedish with captions also in English1994Rapport (Annet vitenskapelig)
  • 81.
    Persson, Christer
    et al.
    SMHI, Forskningsavdelningen, Luftmiljö.
    Omstedt, Gunnar
    SMHI, Forskningsavdelningen, Luftmiljö.
    En modell för beräkning av luftföroreningars spridning och deposition på mesoskala1980Rapport (Annet vitenskapelig)
    Abstract [sv]

    Mängden föroreningar, som förs till atmosfären, har under de senaste trettio åren kraftigt ökats. Deposition av dessa till marken leder till en rad biologiska effekter. Risker för skador på olika ekosystem genom deposition av tex tungmetaller och syra har därför alltmer börjat diskuteras som viktiga lokaliseringskriterier för fossileldade kraftverk och vissa större industrier. Depositionen av bly i omedelbar närhet av livligt trafikerade motorleder är ett annat exempel där negativa miljöeffekter befaras.

    Uppställandet av effektrelaterade utsläppskriterier medför ett behov av redskap för att kunna göra kvantitativa uppskattningar av förväntade depositioner i omgivningen av en källa. För kraftverk kan behovet av information om depositionsfördelningen, som underlag för lokaliseringsbeslut, röra ett område med flera hundra kilometers utsträckning.

    Vid studier av den lokala spridningen runt en punktkälla har under lång tid den gaussiska plymmodellen varit allmänt använd. Den utgör ett enkelt och i många fall mycket bra hjälpmedel, men har avsevärda begränsningar i de fall då depositionsprocesser och kemiska omvandlingar måste inkluderas i beräkningarna. I modeller baserade på diffusionsekvationen, där vissa antaganden om den turbulenta diffusiviteten görs (sk K-teori), finns möjlighet att på ett väsentligt mer realistiskt sätt inkludera processer som rör deposition och kemiska omvandlingar. Nackdelen är dock att den matematiska behandlingen blir mer komplicerad.

    Numeriska lösningar av diffusionsekvationen har använts av tex Bo in & Persson (1975) och Omstedt & Rodhe (1977). I båda fallen gällde tillämpningarna föroreningsspridning på storregional skala. Maul (1977) har presenterat en analytisk lösning, som tillämpats på föroreningsspridning på mesoskala. Svårigheterna vid tillämpningen av K-teorin är framförallt att bestämma riktiga värden på de ingångsparametrar som fordras. För analytiska lösningar finns dessutom matematiska hinder för godtyckliga vind- och diffusivitetsprofiler. Detta har resulterat i att beräkningar med K-modeller hittills huvudsakligen utförts för några enkla medelprofiler.

    Avsikten med föreliggande projekt har varit att utveckla en för praktiskt brukanvändbar spridningsmodell för studier av torr- och våtdepositionen av föroreningar på lokal- och mesoskala, där godtyckliga vind- och diffusivitetsprofiler kan användas. Dessa genereras med hjälp av en gränsskiktsmodell för olika vädersituationer.

  • 82.
    Persson, Christer
    et al.
    SMHI, Forskningsavdelningen, Luftmiljö.
    Robertson, Lennart
    SMHI, Forskningsavdelningen, Luftmiljö.
    Grennfelt, P.
    IVL.
    Kindbom, K.
    IVL.
    Lövblad, Gun
    IVL Swedish Environmental Research Institute.
    Svanberg, P-A
    IVL.
    Luftföroreningsepisoden över södra Sverige 2–4 februari 19871987Rapport (Annet vitenskapelig)
  • 83.
    Persson, Christer
    et al.
    SMHI, Forskningsavdelningen, Luftmiljö.
    Rodhe, H.
    MISU.
    De Geer, L-E
    FOA.
    The Chernobyl accident – A meteorological analysis of how radionucleides reached Sweden1986Rapport (Annet vitenskapelig)
  • 84.
    Persson, Christer
    et al.
    SMHI, Forskningsavdelningen, Luftmiljö.
    Ullerstig, Anders
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Model calculations of dispersion of lindane over Europe: Pilot study with comparisons to easurements around the Baltic Sea and the Kattegat1996Rapport (Annet vitenskapelig)
  • 85.
    Persson, Christer
    et al.
    SMHI, Forskningsavdelningen, Luftmiljö.
    Ullerstig, Anders
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Regional luftmiljöanalys för Västmanlands län baserad på MATCH modell-beräkningar och mätdata: Analys av 1994 års data1997Rapport (Annet vitenskapelig)
  • 86.
    Persson, Christer
    et al.
    SMHI, Forskningsavdelningen, Luftmiljö.
    Ullerstig, Anders
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Robertson, Lennart
    SMHI, Forskningsavdelningen, Luftmiljö.
    Kindbom, Karin
    IVL Swedish Environmental Research Institute.
    Sjöberg, Karin
    IVL Swedish Environmental Research Institute.
    The Swedish Precipitation Chemistry Network: Studies in network design usting the MATCH modelling system and statistical methods1996Rapport (Annet vitenskapelig)
  • 87.
    Persson, Gunn
    et al.
    SMHI, Affärsverksamhet.
    Bärring, Lars
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Kjellström, Erik
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Strandberg, Gustav
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Rummukainen, Markku
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Climate indices for vulnerability assessments2007Rapport (Annet vitenskapelig)
    Abstract [sv]

    Behovet av information om klimatets förändring och dess effekter på olika regioner och sektorer ökar stadigt. För att belysa frågeställningar runt klimatets utveckling, dess påverkan och behov av anpassning behövs projektioner av framtidens klimat. Den generella kunskapen om klimat baseras oftast på erfarenhet av tidigare klimat, väderobservationer, prognoser och återanalyser av historiska data. För att hantera framtidens föränderliga klimat behöver vi utveckla metoder för att förfina användningen av information från klimatmodeller. Klimatindex, formulerade med avnämarperspektiv i fokus och beräknade utifrån data från klimatmodeller, är ett sätt att kommunicera den komplexa frågan om effekter av klimatets framtida utveckling. Klimatindex kan vara välkänd information som summerad nederbörd eller medeltemperaturer men kan också beskriva mer komplexa relationer och då innefatta till exempel tröskelvärden eller exponeringstid för olika förhållanden. I denna rapport beskrivs ett omfattande material av klimatindex baserade på beräkningar med två regionala klimatmodeller utifrån olika utsläppsscenarier och globala klimatmodeller. Materialet har legat till grund för arbetet inom den svenska Klimat- och sårbarhetsutredningen (M2005:03), men har även framtagits i samarbete med andra avnämargrupper. De flesta klimatmodeller och klimatscenarier som ligger till grund för indexberäkningarna har tidigare dokumenterats i andra rapporter men ges här en övergripande beskrivning. Till rapporten bifogas en DVD med det omfattande kartmaterial som illustrerar indexberäkningarna och tillhörande information. Materialet finns även tillgängligt på www.smhi.se.

  • 88.
    Persson, Thomas
    SMHI.
    Measurements of Solar Radiation in Sweden 1983-19982000Rapport (Annet vitenskapelig)
  • 89.
    Persson, Thomas
    SMHI.
    Solar irradiance modelling using satellite retrieved cloudiness: A pilot study1997Rapport (Annet vitenskapelig)
  • 90.
    Robertson, Lennart
    SMHI, Forskningsavdelningen, Luftmiljö.
    Extended back-trajectories by means of adjoint equations2004Rapport (Annet vitenskapelig)
  • 91.
    Robertson, Lennart
    SMHI, Forskningsavdelningen, Luftmiljö.
    Modelling of anthropogenic sulfur deposition to the African and South American continents1996Rapport (Annet vitenskapelig)
  • 92.
    Robertson, Lennart
    et al.
    SMHI, Forskningsavdelningen, Luftmiljö.
    Langner, Joakim
    SMHI, Forskningsavdelningen, Luftmiljö.
    Engardt, Magnuz
    SMHI, Forskningsavdelningen, Luftmiljö.
    MATCH - Meso-scale Atmospheric Transport and Chemistry modelling system1996Rapport (Annet vitenskapelig)
  • 93.
    Rummukainen, Markku
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Methods for statistical downscaling of GCM simulations1997Rapport (Annet vitenskapelig)
    Abstract [en]

    General Circulation Models (GCMs) are used to study the change of climate due to increases in greenhouse gases in the atmosphere. As GCMs operate on !arge spatial scales, and, furthermore, as the GCM-simulated temporal resolution corresponds to monthly averages at best, the usefulness of GCM data in impact studies and other applications is limited. The present-day free troposphere is modeled relatively well by the coarse GCMs, whereas local or even regional characteristics in surface or near-surface climate variables, their variability and the likelihood of extreme events cannot be obtained directly from GCMs. The same is likely true in the case of climate change experiments with GCMs. The results from GCMs can be superimposed on climatological local­ scale time series or interpreted in some other way in order to address the needs of impact studies. This is known as "downscaling" of GCM simulations. In this survey, five different downscaling methods are introduced. These are the conventional, the statistical, the stochastic, the dynamical and the composite methods. Only the statistical and, to a lesser extent, the stochastic approaches are discussed in detail. This survey is a planning document in the SWECLIM program.

  • 94.
    Rummukainen, Markku
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    On the Climate Change debate1999Rapport (Annet vitenskapelig)
  • 95.
    Rummukainen, Markku
    et al.
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Bergström, Sten
    SMHI, Forskningsavdelningen, Hydrologi.
    Källén, Erland
    Meterologi.
    Moen, Lars
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Rodhe, J.
    SMHI.
    Tjernström, M
    SWECLIM - The First Three Years2000Rapport (Annet vitenskapelig)
    Abstract [en]

    The Swedish Regional Clirnate Modeling Program (SWECLIM) is a 6-year national research effort with the airn of providing the Swedish society with more detailed regional climate scenarios than typically available from international global clirnate rnodel simulations. The background is the perceived further enhancernent of the greenhouse effect that is projected to lead to global warming and other changes m the clirnate systern. SWECLIM provides users within governmental organizations, businesses, political decision-rnaking, as well as media and the general public with expertise and synthesis of clirnate change issues, science, results and the detailed regional climate scenarios, to further the understanding of the future changes, to facilitate planning and realization of rnitigation and/or adaptation measures. This requires developrnent and use of regionalization techniques, regional rnodeling tools and other studies of the relevant regional processes and collected data. Apart from hydrological interpretation done of the clirnate scenarios, SWECLIM does not perfonn irnpact studies. Additional concretization of the clirnate scenarios by externa! groups, who possess branch-specific irnpact assessrnent expertise, is supported and encouraged by SWECLIM.

    This report describes the background of the SWECLIM-prograrn, the work undertaken during program phase 1,l asting from 1997 to June 2000. The model developrnent, the prepared regional climate and water resources scenarios, results from statistical downscaling and basic process studies and data analyses, as well as the interaction with users and media are covered. Finally, a brief introduction to the program phase 2 plans are provided.

  • 96.
    Rummukainen, Markku
    et al.
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Bergström, Sten
    SMHI, Forskningsavdelningen, Hydrologi.
    Persson, Gunn
    SMHI, Affärsverksamhet.
    Ressner, Elisabet
    SMHI.
    Anpassning till klimatförändringar: Kartläggning av arbete med sårbarhetsanalyser, anpassningsbehov och anpassningsåtgärder i Sverige till framtida klimatförändring2005Rapport (Annet vitenskapelig)
    Abstract [sv]

    Denna rapport är resultatet av ett uppdrag från Naturvårdsverket till SMHI (NV dnr 235-5045-04H k), som genomförts under hösten 2004. Syftet är att få en överblick över vilka aktörer som för närvarande är aktiva med att analysera eventuella effekter på samhället och att kartlägga anpassningsbehov. Avsikten är också att få en bild av planerade eller redan genomförda insatser och skyddsåtgärder på grund av en befarad klimatförändring. Kartläggningen omfattar ett flertal svenska myndigheter, företag samt ett antal relevanta bransch- och intresseorganisationer och forskningsfinansiärer.I rapporten redovisas även översiktligt de hinder i anpassningsarbetet som identifierats samt önskemål om förbättrat beslutsunderlag.Slutligen förs en översiktlig diskussion om tänkbara sektoriella effekter avav klimatförändringen, baserad på tidigare avnämarkontakter och forskningsinsatser inom området

  • 97.
    Rummukainen, Markku
    et al.
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Räisänen, Jouni
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Ullerstig, Anders
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Bringfelt, Björn
    SMHI.
    Hansson, Ulf
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Graham, Phil
    SMHI, Affärsverksamhet.
    RCA - Rossby Centre regional Atmospheric climate model: model description and results from the first multi-year simulation1997Rapport (Annet vitenskapelig)
  • 98.
    Rummukainen, Markku
    et al.
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    SWECLIM participants, SWECLIM participants
    The Swedish regional climate modeling program 1996-2003: Final report2003Rapport (Annet vitenskapelig)
    Abstract [en]

    The Swedish Regional Climate Modeling Program (SWECLIM) was a 6.5-year national research effort with the aim of providing the Swedish society with more detailed regional climate scenarios than those available from international global climate mode! simulations. SWECLIM built up a new scientific niche in Sweden, namely that of climate modeling, provided users with regionally detailed climate scenarios, expert advice and synthesis of climate changescience. Regional climate modeling was a major activity, supported with studies of climate processes as well as on observed data on the Baltic Sea, regional hydrology and meteorology. The major impact study part was on hydrological modeling, to elaborate the potential impact of regional-scale climate change on hydropower, dam safety and water resources in general. Other types of impact studies were not performed by SWECLIM itself, but means were provided for outside experts to pursue such knowledge. This fmihered the general understanding of climate change and created new insights into planning processes, especially in Sweden, but also on theNordic, European and global arenas.Examples of practical users of the results were experts and decision-makers within national, regional and local administration, organizations, businesses, politicians, as well as media and the general public. These Swedish cfforts on climate science also contributed to international research and assessment networks, and to the quest for better knowledge base to act on in dealing with the climate problem.This repor! provides the final reporting of the SWECLIM-program, building on earlier reports and complements the results published in scientific journals, as reports, presented in meetings and provided to the general public. The focus here is on the work undertaken <luring program phase 2, lasting from July 2000 to June 2003.

  • 99.
    Räisänen, Jouni
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    CO2-induced climate change in northern Europé: comparison of 12 CMIP2 experiments.2000Rapport (Annet vitenskapelig)
  • 100.
    Räisänen, Jouni
    et al.
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Doescher, Ralf
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Simulation of present-day climate in Northen Europé in the HadCM2 OAGCM1998Rapport (Annet vitenskapelig)
123 51 - 100 of 116
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
v. 2.35.7
|