Endre søk
Begrens søket
1 - 22 of 22
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.
  • 1. Bengtsson, L.
    et al.
    Grahn, L
    Olsson, Jonas
    SMHI, Forskningsavdelningen, Hydrologi.
    Hydrological function of a thin extensive green roof in southern Sweden2005Inngår i: Nordic Hydrology, ISSN 0029-1277, E-ISSN 1996-9694, Vol. 36, nr 3, s. 259-268Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The runoff from and the water balance of a thin extensive green roof with sedum-moss have been studied. The soil cover is about 3 cm underlain by a thin drainage layer. The water balance is determined on a monthly basis. The runoff from the green roof is much reduced compared to runoff from hard roofs because of evapotranspiration. The annual runoff is rather close to that of natural river basins. Although most rainy days there is no or little runoff from the roof, the highest observed daily runoff values are close to the daily rainfall. Runoff is initiated when the soil is at field capacity, which for the studied roof corresponds to 9 mm storage. After that, on a not very short time basis, the runoff equals the precipitation. The reduction of the daily runoff can be described in a simple way knowing the daily precipitation, potential evaporation and storage capacity of the green roof.

  • 2.
    Bergström, Sten
    SMHI, Forskningsavdelningen, Hydrologi.
    PRINCIPLES AND CONFIDENCE IN HYDROLOGICAL MODELING1991Inngår i: Nordic Hydrology, ISSN 0029-1277, E-ISSN 1996-9694, Vol. 22, nr 2, s. 123-136Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    General principles in development and application of hydrological models are discussed and related to the confidence in the results. The presentation is mainly based on the experience from the work with the HBV and PULSE models at the Swedish Meteorological and Hydrological Institute between 1971 and 1990 but has also been influenced by other modelling work. It covers a discussion on the optimal complexity of models, use of observations, calibration, control and sensitivity analysis. Special attention is given to the uncertainties encountered when using hydrological models for the simulation of extreme floods and long-term scenario simulations. Finally a few ethical problems in modelling are mentioned.

  • 3.
    Brandt, Maja
    SMHI, Samhälle och säkerhet.
    SIMULATION OF RUNOFF AND NITRATE TRANSPORT FROM MIXED BASINS IN SWEDEN1990Inngår i: Nordic Hydrology, ISSN 0029-1277, E-ISSN 1996-9694, Vol. 21, nr 1, s. 13-34Artikkel i tidsskrift (Fagfellevurdert)
  • 4.
    Brandt, Maja
    et al.
    SMHI, Samhälle och säkerhet.
    Bergström, Sten
    SMHI, Forskningsavdelningen, Hydrologi.
    INTEGRATION OF FIELD DATA INTO OPERATIONAL SNOWMELT-RUNOFF MODELS1994Inngår i: Nordic Hydrology, ISSN 0029-1277, E-ISSN 1996-9694, Vol. 25, nr 1-2, s. 101-112Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Conceptual runoff models have become standard tools for operational hydrological forecasting in Scandinavia. These models are normally based on observations from the national climatological networks, but in mountainous areas the stations are few and sometimes not representative. Due to the great economic importance of good hydrological forecasts for the hydro-power industry attempts have been made to improve the model simulations by support from field observations of the snowpack. The snowpack has been mapped by several methods; airborne gamma-spectrometry, airborne georadars, satellites and by conventional snow courses. The studies cover more than ten years of work in Sweden. The conclusion is that field observations of the snow cover have a potential for improvement of the forecasts of inflow to the reservoirs in the mountainous part of the country, where the climatological data coverages is poor. This is pronounced during years with unusual snow distribution. The potential for model improvement is smaller in the climatologically more homogeneous forested lowlands, where the climatological network is denser. The costs of introduction of airborne observations into the modelling procedure are high and can only be justified in areas of great hydropower potential.

  • 5.
    Brandt, Maja
    et al.
    SMHI, Samhälle och säkerhet.
    Bergström, Sten
    SMHI, Forskningsavdelningen, Hydrologi.
    Sandén, Per
    SMHI, Forskningsavdelningen, Hydrologi.
    ENVIRONMENTAL IMPACTS OF AN OLD MINE TAILINGS DEPOSIT - MODELING OF WATER-BALANCE, ALKALINITY AND PH1987Inngår i: Nordic Hydrology, ISSN 0029-1277, E-ISSN 1996-9694, Vol. 18, nr 4-5, s. 291-300Artikkel i tidsskrift (Fagfellevurdert)
  • 6.
    Carlsson, Bengt
    et al.
    SMHI, Forskningsavdelningen, Hydrologi.
    Sanner, Håkan
    SMHI.
    Modelling influence of river regulation on runoff to the Gulf of Bothnia1996Inngår i: Nordic Hydrology, ISSN 0029-1277, E-ISSN 1996-9694, Vol. 27, nr 5, s. 337-350Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Runoff from a land area of approximately 490,000 km(2) enters the Gulf of Bothnia. This runoff is of essential importance for the flushing of the Gulf. a change in the volume of runoff effects the residence time. There are many natural as well as man made changes in the runoff, both in the form of long-term changes over many years and those occurring within one year. The most significant man made changes come from hydropower regulation. This report describes the effect on runoff from the development of the hydropower plants in Sweden and Finland by means of comparing recorded regulated runoff and simulated natural runoff. A recent time period, 1980-91, and a time period before regulation, 1925-36, were simulated. The monthly magnitudes of the redistributed flows were found to be on average 1,700 m(3)/s. The maximum redistributed monthly flow in May - June reached 5,000-6,000 m(3)/s.

  • 7.
    Gardelin, Marie
    et al.
    SMHI, Affärsverksamhet.
    Lindström, Göran
    SMHI, Forskningsavdelningen, Hydrologi.
    Priestley-Taylor evapotranspiration in HBV-simulations1997Inngår i: Nordic Hydrology, ISSN 0029-1277, E-ISSN 1996-9694, Vol. 28, nr 4-5, s. 233-246Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

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

  • 8.
    Harlin, Joakim
    SMHI.
    DEVELOPMENT OF A PROCESS ORIENTED CALIBRATION SCHEME FOR THE HBV HYDROLOGICAL MODEL1991Inngår i: Nordic Hydrology, ISSN 0029-1277, E-ISSN 1996-9694, Vol. 22, nr 1, s. 15-36Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A process oriented calibration scheme (POC), developed for the HBV hydrological model is presented. Twelve parameters were calibrated in two steps. Firstly, initial parameter estimates were made from recession analysis of observed runoff. Secondly, the parameters were calibrated individually in an iteration loop starting with the snow routine, over the soil routine and finally the runoff-response function. This was done by minimizing different objective functions for different parameters and only over subperiods where the parameters were active. Approximately three hundred and fifty objective function evaluations were needed to find the optimal parameter set, which resulted in a computer time of about 17 hours on a 386 processor PC for a ten-year calibration period. Experiments were also performed with fine tuning as well as direct search of the response surface, where the parameters were allowed to change simultaneously. A calibration period length of between two and six years was found sufficient to find optimal parameters in the test basins. The POC scheme yielded as good model performance as after a manual calibration.

  • 9.
    Harlin, Joakim
    SMHI.
    MODELING THE HYDROLOGICAL RESPONSE OF EXTREME FLOODS IN SWEDEN1992Inngår i: Nordic Hydrology, ISSN 0029-1277, E-ISSN 1996-9694, Vol. 23, nr 4, s. 227-244Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Hydrological models are today used for simulating extreme floods with the purpose of designing dams and spillways. In doing so, an extrapolation beyond the floods of the calibration period is made. This paper addresses this problem in connection to the HBV hydrological model. The model component describing flood dynamics, the runoff-response function, is studied. The methodology has been to calibrate different runoff-response functions over small to moderately large floods and to verify the performance over independent periods containing large experienced floods. Furthermore, the different model versions were run with extreme rainfall in order to generate design floods. It was found that the five-parameter response function of the original HBV model could be replaced by nonlinear functions including fewer parameters. However, it was difficult to select any response function formulation as significantly better than the others when extreme floods larger than those of the calibration period were simulated.

  • 10.
    Johansson, Barbro
    SMHI, Affärsverksamhet.
    Areal precipitation and temperature in the Swedish mountains - An evaluation from a hydrological perspective2000Inngår i: Nordic Hydrology, ISSN 0029-1277, E-ISSN 1996-9694, Vol. 31, nr 3, s. 207-228Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper presents an evaluation of three different methods for estimation of areal precipitation and temperature, with special emphasis on their applicability for runoff modelling in the Swedish mountains. All three methods estimate the areal values as a weighted mean of the observations at nearby meteorological stations. The weights are determined by: 1) a manual subjective selection of the most representative stations 3) inverse square distance weighting 4) optimal interpolation. The methods were tested in an area with complex topography and precipitation gradients. The evaluation included comparison of areal estimates, verification against point observations and the water balance equation, and sensitivity analyses with respect to method parameters and network changes. The evaluation showed that for simple runoff modelling the subjective and optimal interpolation methods performed equally well, and considerably better than inverse-distance weighting. The evaluation also showed that none of the methods correctly described the spatial variation in precipitation and temperature in the investigated region. They are thus not directly applicable for nbn-routine modelling applications where the estimation of runoff is not the sole objective. All methods proved to be sensitive to the selection of parameter values, which pointed to possible improvements of the estimates. The optimal interpolation method seemed to be the least sensitive to changes in the meteorological network.

  • 11.
    Johansson, Barbro
    et al.
    SMHI, Affärsverksamhet.
    Jutman, Torbjörn
    SMHI, Samhälle och säkerhet.
    HYDROLOGICAL MAPS DEVELOPMENT OF A SYSTEM FOR CALCULATION AND PRESENTATION1986Inngår i: Nordic Hydrology, ISSN 0029-1277, E-ISSN 1996-9694, Vol. 17, nr 4-5, s. 229-236Artikkel i tidsskrift (Fagfellevurdert)
  • 12.
    Johnell, Anna
    et al.
    SMHI, Affärsverksamhet.
    Lindström, Göran
    SMHI, Forskningsavdelningen, Hydrologi.
    Olsson, Jonas
    SMHI, Forskningsavdelningen, Hydrologi.
    Deterministic evaluation of ensemble streamflow predictions in Sweden2007Inngår i: Nordic Hydrology, ISSN 0029-1277, E-ISSN 1996-9694, Vol. 38, nr 4-5, s. 441-450Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A system for ensemble streamflow prediction, ESP, has been operational at SMHI since July 2004, based on 50 meteorological ensemble forecasts from ECMWF. Hydrological ensemble forecasts are produced daily for 51 basins in Sweden. All ensemble members, as well as statistics (minimum, 25% quartile, median, 75% quartile and maximum), are stored in a database. This paper presents an evaluation of the first 18 months of ESP median forecasts from this system, and in particular their performance in comparison with today's categorical forecast. The evaluation was made in terms of three statistical measures: bias B, root mean square error RMSE and absolute peak flow error PE. For ESP forecasts the bias ranged between -20% and 80% with a systematic overestimation for Sweden as a whole. A comparison between bias in input precipitation and ESP output, respectively, revealed only a weak relationship, but streamflow overestimation is likely related mainly to model properties. The results from the streamflow forecast comparison showed that the ESP median in deterministic terms performs overall as well as the presently used categorical forecast. Further, ESP has the advantage of providing at least a qualitative measure of the uncertainty in the forecasts, with probability forecasts being the ultimate goal.

  • 13.
    Kjellström, Erik
    et al.
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Doescher, Ralf
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Meier, Markus
    SMHI, Forskningsavdelningen, Oceanografi.
    Atmospheric response to different sea surface temperatures in the Baltic Sea: coupled versus uncoupled regional climate model experiments2005Inngår i: Nordic Hydrology, ISSN 0029-1277, E-ISSN 1996-9694, Vol. 36, nr 4-5, s. 397-409Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A climate change experiment with a fully coupled high resolution regional atmosphere-ocean model for the Baltic Sea is compared to an experiment with a stand-alone regional atmospheric model. Both experiments simulate 30-yr periods with boundary data from the same global climate model system. This particular global model system simulates very high sea surface temperatures during summer for the Baltic Sea at the end of this century under the investigated emission scenario. We show that the sea surface temperatures are less warm in the coupled regional model compared to the global model system and that this difference is dependent on the atmospheric circulation. In summers with a high NAO index and thereby relatively strong westerly flow over the North Atlantic the differences between the two models are small, while in summers with a weaker, more northerly flow over the Baltic Sea the differences are very large. The higher sea surface temperatures in the uncoupled experiment lead to an intensified hydrological cycle over the Baltic Sea, with more than 30% additional precipitation in summer taken as an average over the full 30-yr period and over the entire Baltic Sea. The differences are mostly local, over the sea, but there are differences in surrounding land areas.

  • 14.
    Lindström, Göran
    SMHI, Forskningsavdelningen, Hydrologi.
    A simple automatic calibration routine for the HBV model1997Inngår i: Nordic Hydrology, ISSN 0029-1277, E-ISSN 1996-9694, Vol. 28, nr 3, s. 153-168Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A simple, but efficient, method for automatic calibration of the conceptual HBV rainfall-runoff model was developed. A new criterion, which combines the commonly used efficiency criterion R-2 and the relative volume error was introduced. 2 values nearly as high as those Optimising this combined criterion resulted in R-2 for optimising only R-2, but With much smaller volume errors. An earlier automatic calibration method for the HBV model relied on the use of different criteria for different parameters. With the simplification to one single criterion, the optimum search method could be made more efficient. The optimisation is made for one parameter at a time, while the others are kept constant. This one-dimensional optimisation is repeated in a loop for all parameters. A new loop is performed as long as there is a sufficiently large improvement since the last one. After each loop a search is made in the direction which is defined by the differences in parameter values between the two latest loops. The calibration routine was developed for, and tested with, the HBV model, but it should be general enough to be applicable to other models as well.

  • 15.
    Lindström, Göran
    et al.
    SMHI, Forskningsavdelningen, Hydrologi.
    RODHE, A
    MODELING WATER EXCHANGE AND TRANSIT TIMES IN TILL BASINS USING O-181986Inngår i: Nordic Hydrology, ISSN 0029-1277, E-ISSN 1996-9694, Vol. 17, nr 4-5, s. 325-334Artikkel i tidsskrift (Fagfellevurdert)
  • 16.
    Olsson, Jonas
    et al.
    SMHI, Forskningsavdelningen, Hydrologi.
    Södling, Johan
    SMHI, Affärsverksamhet.
    Berg, Peter
    SMHI, Forskningsavdelningen, Hydrologi.
    Wern, Lennart
    SMHI, Samhälle och säkerhet.
    Eronn, Anna
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Short-duration rainfall extremes in Sweden: a regional analysis2019Inngår i: Nordic Hydrology, ISSN 0029-1277, E-ISSN 1996-9694, Vol. 50, nr 3, s. 945-960Artikkel i tidsskrift (Fagfellevurdert)
  • 17.
    Omstedt, Anders
    SMHI, Forskningsavdelningen, Oceanografi.
    FORECASTING WATERCOOLING IN THE KATTEGAT, THE ORESUND, THE BELT SEA AND THE ARKONA BASIN1987Inngår i: Nordic Hydrology, ISSN 0029-1277, E-ISSN 1996-9694, Vol. 18, nr 4-5, s. 247-258Artikkel i tidsskrift (Fagfellevurdert)
  • 18.
    Omstedt, Anders
    et al.
    SMHI, Forskningsavdelningen, Oceanografi.
    MURTHY, CR
    ON CURRENTS AND VERTICAL MIXING IN LAKE-ONTARIO DURING SUMMER STRATIFICATION1994Inngår i: Nordic Hydrology, ISSN 0029-1277, E-ISSN 1996-9694, Vol. 25, nr 3, s. 213-232Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Currents and vertical mixing characteristics were investigated on the basis of time series of current meter and temperature data from a summer-stratified period in Lake Ontario. The experimental set up consisted of seven current meters distributed in one vertical line from 12 m below the surface to 1 m above the lake bottom at a total depth of 143 m. The period considered for the analysis was from June to September, 1991. The currents showed pronounced oscillations with two significant kinetic energy peaks, one at about 17 hours due to inertial motions, and one at 10 days, probably due to meteorological forcing. The current shear in the hypolimnion was strong enough to overcome stability and generate turbulence (Richardson numbers below 0.25) and there was probably turbulence enough available to keep the matter (almost neutral buoyant particles) in the whole Nepheloid bottom layer in suspension. In the thermocline region the turbulence was mainly damped (Richardson numbers above 1), but some events with lower Richardson numbers were also calculated indicating increased mixing during these events. By analysing filtered and unfiltered current meter data it was found that the shear-generated turbulence in the hypolimnion was mainly due to the meteorologically forced currents. In the thermocline region, however, the vertical shear associated with the inertial oscillation had a greater impact on the mixing.

  • 19.
    Pers, Charlotta
    et al.
    SMHI, Forskningsavdelningen, Hydrologi.
    Persson, I
    Simulation of a biogeochemical model in different lakes2003Inngår i: Nordic Hydrology, ISSN 0029-1277, E-ISSN 1996-9694, Vol. 34, nr 5, s. 543-558Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Eutrophication, caused by nutrients leached from soil and emitted from point sources, is a well-known problem in many Swedish lakes. There are several countermeasures that can be used to reduce eutrophication. A model that can simulate the biogeochemical response to different management scenarios may help with nutrient reducing strategies. Results from applications with such a model to different types of lakes are presented in this paper. The most important variables simulated by the model are dissolved nutrient concentrations (nitrogen and phosphorus) and phytoplankton. Other variables include nitrogen fixating cyanobacteria, sediments, and zooplankton. In total, 14 state variables are simulated. Nutrients are supplied through tributaries, and the temperature and vertical mixing forced by meteorological input. The model is able to simulate effects of changing nutrients and plankton dynamics. It is promising as an instrument for evaluating various measures to improve water quality in lakes. However, for the lakes the model has been applied to, the model has been calibrated to available observations. Non-monitored lakes could also be interesting to simulate, therefore the parameters of the model set-ups are discussed in this paper.

  • 20.
    Pettersson, Anna
    et al.
    SMHI, Forskningsavdelningen, Hydrologi.
    Arheimer, Berit
    SMHI, Forskningsavdelningen, Hydrologi.
    Johansson, Barbro
    SMHI, Affärsverksamhet.
    Nitrogen concentrations simulated with HBV-N: New response function and calibration strategy - Paper presented at the Nordic Hydrological Conference (Uppsala, Sweden June, 2000)2001Inngår i: Nordic Hydrology, ISSN 0029-1277, E-ISSN 1996-9694, Vol. 32, nr 3, s. 227-248Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    HBV-N is a conceptual process-based model for simulation of transformation and transport of nitrogen on the catchment scale. This paper presents further development with focus on the response function and calibration procedures. Evaluation of the model routines was made in 12 test basins in southern Sweden (without or with only few lakes). Previous versions of HBV-N included a HBV version with a single reservoir in the response function. The presented results show that both nitrogen concentrations and water discharge simulations improved when a second reservoir was introduced. The two-reservoir model was found to be more well-posed for description of residence-times and flow paths. On average, this resulted in an increase in explained variance (R-2) for nitrogen concentrations by 0.3. Multiple-response split-sample calibration was found to further improve the model performance and reliability. In previous applications HBV-N has been applied by using single-response calibration. However, simultaneous calibration of water discharge and nitrogen improved the R2 for nitrogen concentrations by about 0.1 (range 0.02-0.25), but did not affect the simulation of water discharge. This new calibration strategy forces the hydrological parameters to a new optimum, and reduces the level of uncertainty for both hydrochemical and hydrological modelling.

  • 21.
    Rummukainen, Markku
    et al.
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Räisänen, Jouni
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Bjorge, D
    Christensen, J H
    Christensen, O B
    Iversen, T
    Jylha, K
    Olafsson, H
    Tuomenvirta, H
    Regional climate scenarios for use in Nordic water resources studies2003Inngår i: Nordic Hydrology, ISSN 0029-1277, E-ISSN 1996-9694, Vol. 34, nr 5, s. 399-412Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    According to global climate projections, a substantial global climate change will occur during the next decades, under the assumption of continuous anthropogenic climate forcing. Global models, although fundamental in simulating the response of the climate system to anthropogenic forcing are typically geographically too coarse to well represent many regional or local features. In the Nordic region, climate studies are conducted in each of the Nordic countries to prepare regional climate projections with more detail than in global ones. Results so far indicate larger temperature changes in the Nordic region than in the global mean, regional increases and decreases in net precipitation, longer growing season, shorter snow season etc. These in turn affect runoff, snowpack, groundwater, soil frost and moisture, and thus hydropower production potential, flooding risks etc. Regional climate models do not yet fully incorporate hydrology. Water resources studies are carried out off-line using hydrological models. This requires archived meteorological output from climate models. This paper discusses Nordic regional climate scenarios for use in regional water resources studies. Potential end-users of water resources scenarios are the hydropower industry, dam safety instances and planners of other lasting infrastructure exposed to precipitation, river flows and flooding.

  • 22.
    Rutgersson, Anna
    et al.
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Bumke, K
    Clemens, M
    Foltescu, Valentin
    SMHI.
    Lindau, R
    Michelson, Daniel
    SMHI, Samhälle och säkerhet.
    Omstedt, Anders
    SMHI, Forskningsavdelningen, Oceanografi.
    Precipitation estimates over the Baltic Sea: Present state of the art2001Inngår i: Nordic Hydrology, ISSN 0029-1277, E-ISSN 1996-9694, Vol. 32, nr 4-5, s. 285-314Artikkel i tidsskrift (Fagfellevurdert)
    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.

1 - 22 of 22
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. 2.35.8
|