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  • 1. Alfredsson, L.
    et al.
    Segersson, David
    SMHI, Forskningsavdelningen, Meteorologi.
    Hillert, J.
    Kockum, I.
    Strid, P.
    Olsson, T.
    Bellander, T.
    Hedstrom, A. K.
    Association Between Exposure to Combustion-Related Air Pollution and Multiple Sclerosis Risk2023Ingår i: Multiple Sclerosis Journal, ISSN 1352-4585, E-ISSN 1477-0970, Vol. 29, s. 99-99Artikel i tidskrift (Refereegranskat)
    Ladda ner fulltext (pdf)
    Association between exposure to combustion-related air pollution and multiple sclerosis risk
  • 2.
    Alpfjord Wylde, Helene
    et al.
    SMHI, Affärsverksamhet.
    Asker, Christian
    SMHI, Forskningsavdelningen, Meteorologi.
    Bennet, Cecilia
    SMHI, Forskningsavdelningen, Meteorologi.
    Segersson, David
    SMHI, Forskningsavdelningen, Meteorologi.
    Quantification of population exposure to PM10, PM2.5 and NO2 and estimated health impacts for 2019 and 20302023Rapport (Övrigt vetenskapligt)
    Abstract [sv]

    Halter av NO2, PM10 och PM2.5 har beräknats för hela Sverige för år 2019 och för två scenarier 2030 i den här studien. Beräkningar har gjorts med en ny metodik som möjliggör en nästan helt sömlös kombination av spridningsmodellering på regional och urban skala utan att dubbelräkna emissioner. Föroreningshalter har beräknats på 250x250 m2 upplösning, vilket ger ett unikt komplett och detaljerat dataset på nationell skala. Metodiken kan väl reproducera uppmätta föroreningshalter vid de flesta urbana bakgrundsstationerna i modelldomänet. Den spatiala upplösningen på 250 m fångar koncentrationsgradienter av vikt för exponeringsberäkningar. En styrka med att använda spridningsmodeller för att beräkna föroreningshalter är den direkta kopplingen till emissionsinventeringar och projektioner.

    Modellerade föroreningshalter kombineras med griddad befolkningsdata för att beräkna exponering. Den befolkningsviktade årsmedelexponeringen är 5,08 μg/m3 för NO2, 9,95 μg/m3 för PM10 och 5,21 μg/m3 för PM2.5 år 2019. En stor minskning, med cirka 2 μg/m3till 2030, beräknas för exponering av NO2. Exponeringen för PM10 och PM2.5 minskar också till 2030, men inte lika drastiskt, med ungefär 0,2 μg/m3.

    En generell slutsats är att exponeringen är högre i åldersspannet 21-50 år. En förklaring är dessa åldersgrupper oftare bor i urbana områden, med mer utsläpp och högre föroreningshalter.

    Noll procent av befolkningen exponeras för halter över den årliga miljökvalitetsnormen för NO2, PM10 och PM2.5, varken år 2019 eller 2030. Det ska dock noteras att modellresultaten representerar årsmedelvärden av urbana bakgrundskoncentrationer, inte lokala hotspots.

    De modellbaserade beräkningarna av exponeringen för PM2.5 och lokalt genererad NO2 har använts i en nationell hälsokonsekvensberäkning. Hälsokonsekvensberäkningen liknar en nyligen publicerad beräkning avseende 2019, av förtida dödsfall och uppkomst av främst kroniska sjukdomar. Våra resultat avviker i olika riktning från resultaten i liknande beräkningar. En avgörande och komplicerad anledning till skillnader i de beräknade hälsokonsekvenserna är vilka exponerings-responssamband för specifika föroreningar som man baserar sina beräkningar på, riskkurvans form och om det finns någon säker nivå under vilken sambandet upphör. I denna studie har vi valt att luta oss mot den vetenskapliga evidens som ges av högkvalitativa epidemiologiska studier för att sambanden mellan partikelhalt och dödlighet är supra-linjära med den brantaste riskökningen vid de lägsta halterna, att effekterna är starkare nära källan samt att det inte finns stöd för någon tröskelnivå under vilken halten saknar betydelse. När vi räknar ihop antal förtida dödsfall per år som den regionala bakgrundshalten av PM2.5 beräknas orsaka med de dödsfall som beräknas uppkomma till följd av partikelutsläpp på hemorten så blir summan 4 264 förtida dödsfall relaterade till föroreningssituationen 2019. För samma exponeringssituation uppskattar vi att de lokalt genererade bidragettill NO2-halten leder till ytterligare 428 förtida dödsfall per år.

    2030 beräknas befolkningsexponeringen för PM2.5 från den regionala bakgrunden ha minskat med omkring 2 % och från urbana källor med 22 % jämfört med 2019, vilket indikerar hur mycket antalet förtida dödsfall skulle reduceras om allt övrigt är oförändrat.

    Ladda ner fulltext (pdf)
    Quantification of population exposure to PM10, PM2.5 and NO2 and estimated health impacts for 2019 and 2030
  • 3.
    Amorim, Jorge Humberto
    et al.
    SMHI, Forskningsavdelningen, Luftmiljö.
    Asker, Christian
    SMHI, Forskningsavdelningen, Luftmiljö.
    Belusic, Danijel
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Carvalho, Ana
    SMHI, Forskningsavdelningen, Luftmiljö.
    Engardt, Magnuz
    SMHI, Forskningsavdelningen, Luftmiljö.
    Gidhagen, Lars
    SMHI, Forskningsavdelningen, Luftmiljö.
    Hundecha, Yeshewatesfa
    SMHI, Forskningsavdelningen, Hydrologi.
    Körnich, Heiner
    SMHI, Forskningsavdelningen, Meteorologi.
    Lind, Petter
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Olsson, Esbjörn
    SMHI, Forskningsavdelningen, Meteorologi.
    Olsson, Jonas
    SMHI, Forskningsavdelningen, Hydrologi.
    Segersson, David
    SMHI, Forskningsavdelningen, Luftmiljö.
    Strombäck, Lena
    SMHI, Forskningsavdelningen, Hydrologi.
    Joe, Paul
    Baklanov, Alexander
    Integrated Urban Services for European cities: the Stockholm case2018Ingår i: WMO Bulletin, ISSN 0042-9767, Vol. 67, nr 2, s. 33-40Artikel i tidskrift (Refereegranskat)
    Ladda ner fulltext (pdf)
    fulltext
  • 4.
    Amorim, Jorge Humberto
    et al.
    SMHI, Forskningsavdelningen, Luftmiljö.
    Segersson, David
    SMHI, Forskningsavdelningen, Luftmiljö.
    Körnich, Heiner
    SMHI, Forskningsavdelningen, Meteorologi.
    Asker, Christian
    SMHI, Forskningsavdelningen, Luftmiljö.
    Olsson, Esbjörn
    SMHI, Forskningsavdelningen, Meteorologi.
    Gidhagen, Lars
    SMHI, Forskningsavdelningen, Luftmiljö.
    High resolution simulation of Stockholm's air temperature and its interactions with urban development2020Ingår i: Urban Climate, E-ISSN 2212-0955, Vol. 32, artikel-id 100632Artikel i tidskrift (Refereegranskat)
    Ladda ner fulltext (pdf)
    fulltext
  • 5. Andersson, John
    et al.
    Sundstrom, Anna
    Nordin, Maria
    Segersson, David
    SMHI, Forskningsavdelningen, Meteorologi.
    Forsberg, Bertil
    Adolfsson, Rolf
    Oudin, Anna
    PM2.5 and Dementia in a Low Exposure Setting: The Influence of Odor Identification Ability and APOE2023Ingår i: Journal of Alzheimer's Disease, ISSN 1387-2877, E-ISSN 1875-8908, Vol. 92, nr 2, s. 679-689Artikel i tidskrift (Refereegranskat)
    Ladda ner fulltext (pdf)
    fulltext
  • 6.
    Andersson, Tage
    et al.
    SMHI, Forskningsavdelningen.
    Gustafsson, Nils
    SMHI, Forskningsavdelningen, Meteorologi.
    COAST OF DEPARTURE AND COAST OF ARRIVAL - 2 IMPORTANT CONCEPTS FOR THE FORMATION AND STRUCTURE OF CONVECTIVE SNOWBANDS OVER SEAS AND LAKES1994Ingår i: Monthly Weather Review, ISSN 0027-0644, E-ISSN 1520-0493, Vol. 122, nr 6, s. 1036-1049Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A case with intense convective snowbands over the Baltic Sea is examined using the High-Resolution Limited Area Model. The intention is to gain a better insight into the importance of the shape of the cowta, the orography, and the surface roughness on the formation and evolution of the snowbands. Among the factors studied am the shape of the coast from which the air departs and that to which it arrives. These factors are so important that two new concepts-coast of departure and coast of arrival-are introduced.

  • 7. Ashcroft, Linden
    et al.
    Coll, Joan Ramon
    Gilabert, Alba
    Domonkos, Peter
    Brunet, Manola
    Aguilar, Enric
    Castella, Merce
    Sigro, Javier
    Harris, Ian
    Undén, Per
    SMHI, Forskningsavdelningen, Meteorologi.
    Jones, Phil
    A rescued dataset of sub-daily meteorological observations for Europe and the southern Mediterranean region, 1877-20122018Ingår i: Earth System Science Data, ISSN 1866-3508, E-ISSN 1866-3516, Vol. 10, nr 3, s. 1613-1635Artikel i tidskrift (Refereegranskat)
    Ladda ner fulltext (pdf)
    fulltext
  • 8. Baron, P.
    et al.
    Murtagh, D. P.
    Urban, J.
    Sagawa, H.
    Ochiai, S.
    Kasai, Y.
    Kikuchi, K.
    Khosrawi, F.
    Körnich, Heiner
    SMHI, Forskningsavdelningen, Meteorologi.
    Mizobuchi, S.
    Sagi, K.
    Yasui, M.
    Observation of horizontal winds in the middle-atmosphere between 30 degrees S and 55 degrees N during the northern winter 2009-20102013Ingår i: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 13, nr 12, s. 6049-6064Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Although the links between stratospheric dynamics, climate and weather have been demonstrated, direct observations of stratospheric winds are lacking, in particular at altitudes above 30 km. We report observations of winds between 8 and 0.01 hPa (similar to 35-80 km) from October 2009 to April 2010 by the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) on the International Space Station. The altitude range covers the region between 35-60 km where previous space-borne wind instruments show a lack of sensitivity. Both zonal and meridional wind components were obtained, though not simultaneously, in the latitude range from 30 degrees S to 55 degrees N and with a single profile precision of 7-9 ms(-1) between 8 and 0.6 hPa and better than 20 ms(-1) at altitudes above. The vertical resolution is 5-7 km except in the upper part of the retrieval range (10 km at 0.01 hPa). In the region between 1-0.05 hPa, an absolute value of the mean difference <2 ms(-1) is found between SMILES profiles retrieved from different spectroscopic lines and instrumental settings. Good agreement (absolute value of the mean difference of similar to 2 ms(-1)) is also found with the European Centre for Medium-Range Weather Forecasts (ECMWF) analysis in most of the stratosphere except for the zonal winds over the equator (difference >5 ms(-1)). In the mesosphere, SMILES and ECMWF zonal winds exhibit large differences (>20 ms(-1)), especially in the tropics. We illustrate our results by showing daily and monthly zonal wind variations, namely the semi-annual oscillation in the tropics and reversals of the flow direction between 50-55 degrees N during sudden stratospheric warmings. The daily comparison with ECMWF winds reveals that in the beginning of February, a significantly stronger zonal westward flow is measured in the tropics at 2 hPa compared to the flow computed in the analysis (difference of similar to 20 ms(-1)). The results show that the comparison between SMILES and ECMWF winds is not only relevant for the quality assessment of the new SMILES winds, but it also provides insights on the quality of the ECMWF winds themselves. Although the instrument was not specifically designed for measuring winds, the results demonstrate that space-borne sub-mm wave radiometers have the potential to provide good quality data for improving the stratospheric winds in atmospheric models.

    Ladda ner fulltext (pdf)
    fulltext
  • 9. Becker, Daniel
    et al.
    Heitland, Jonas
    Carlsson, Philip T. M.
    Elm, Jonas
    Olenius, Tinja
    SMHI, Forskningsavdelningen, Meteorologi.
    Toedter, Sophia
    Kharrazizadeh, Amir
    Zeuch, Thomas
    Real-time monitoring of aerosol particle formation from sulfuric acid vapor at elevated concentrations and temperatures2022Ingår i: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084Artikel i tidskrift (Refereegranskat)
    Ladda ner fulltext (pdf)
    Real-time monitoring of aerosol particle formation from sulfuric acid vapor at elevated concentrations and temperatures
  • 10. Belova, Evgenia
    et al.
    Kirkwood, Sheila
    Voelger, Peter
    Chatterjee, Sourav
    Satheesan, Karathazhiyath
    Hagelin, Susanna
    SMHI, Forskningsavdelningen, Meteorologi.
    Lindskog, Magnus
    SMHI, Forskningsavdelningen, Meteorologi.
    Körnich, Heiner
    SMHI, Forskningsavdelningen, Meteorologi.
    Validation of Aeolus winds using ground-based radars in Antarctica and in northern Sweden2021Ingår i: Atmospheric Measurement Techniques, ISSN 1867-1381, E-ISSN 1867-8548, Vol. 14, nr 8, s. 5415-5428Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Winds measured by lidar from the Aeolus satellite are compared with winds measured by two ground-based radars - MARA in Antarctica (70.77 degrees S, 11.73 degrees E) and ES-RAD (67.88 degrees N, 21.10 degrees E) in Arctic Sweden - for the period 1 July-31 December 2019. Aeolus is a demonstrator mission to test whether winds measured by Doppler lidar from space can have sufficient accuracy to contribute to improved weather forecasting. A comprehensive programme of calibration and validation has been undertaken following the satellite launch in 2018, but, so far, direct comparison with independent measurements from the Arctic or Antarctic regions have not been made. The comparison covers heights from the low troposphere to just above the tropopause. Results for each radar site are presented separately for Rayleigh (clear) winds, Mie (cloudy) winds, sunlit ("summer") and non-sunlit ("winter") seasons, and ascending and descending satellite tracks. Horizontally projected line-of-sight (HLOS) winds from Aeolus, reprocessed using baseline 2B10, for passes within 100 km of the radar sites, are compared with HLOS winds calculated from 1 h averaged radar horizontal wind components. The agreement in most data subsets is very good, with no evidence of significant biases (<1ms(-1)). Possible biases are identified for two subsets (about -2ms(-1) for the Rayleigh winds for the descending passes at MARA and about 2ms(-1) for the Mie winds for the ascending passes at ESRAD, both in winter), but these are only marginally significant. A robust significant bias of about 7ms(-1) is found for the Mie winds for the ascending tracks at MARA in summer. There is also some evidence for increased random error (by about 1ms(-1) / for the Aeolus Mie winds at MARA in summer compared to winter. This might be related to the presence of sunlight scatter over the whole of Antarctica as Aeolus transits across it during summer.

    Ladda ner fulltext (pdf)
    Validation of Aeolus winds using ground-based radars in Antarctica and in northern Sweden
  • 11. Belova, Evgenia
    et al.
    Voelger, Peter
    Kirkwood, Sheila
    Hagelin, Susanna
    SMHI, Forskningsavdelningen, Meteorologi.
    Lindskog, Magnus
    SMHI, Forskningsavdelningen, Meteorologi.
    Körnich, Heiner
    SMHI, Forskningsavdelningen, Meteorologi.
    Chatterjee, Sourav
    Satheesan, Karathazhiyath
    Validation of wind measurements of two mesosphere-stratosphere-troposphere radars in northern Sweden and in Antarctica2021Ingår i: Atmospheric Measurement Techniques, ISSN 1867-1381, E-ISSN 1867-8548, Vol. 14, nr 4, s. 2813-2825Artikel i tidskrift (Refereegranskat)
    Ladda ner fulltext (pdf)
    Validation of wind measurements of two mesosphere-stratosphere-troposphere radars in northern Sweden and in Antarctica
  • 12.
    Belusic, Danijel
    et al.
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    de Vries, Hylke
    Dobler, Andreas
    Landgren, Oskar
    Lind, Petter
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Lindstedt, David
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Pedersen, Rasmus A.
    Carlos Sanchez-Perrino, Juan
    Toivonen, Erika
    van Ulft, Bert
    Wang, Fuxing
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Andrae, Ulf
    SMHI, Forskningsavdelningen, Meteorologi.
    Batrak, Yurii
    Kjellström, Erik
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Lenderink, Geert
    Nikulin, Grigory
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Pietikainen, Joni-Pekka
    Rodriguez-Camino, Ernesto
    Samuelsson, Patrick
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    van Meijgaard, Erik
    Wu, Minchao
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    HCLIM38: a flexible regional climate model applicable for different climate zones from coarse to convection-permitting scales2020Ingår i: Geoscientific Model Development, ISSN 1991-959X, E-ISSN 1991-9603, Vol. 13, nr 3, s. 1311-1333Artikel i tidskrift (Refereegranskat)
    Ladda ner fulltext (pdf)
    fulltext
  • 13.
    Bengtsson,, Lennart
    et al.
    SMHI.
    Gustafsson, Nils
    SMHI, Forskningsavdelningen, Meteorologi.
    Döös, Bo
    SMHI.
    Söderman, Daniel
    Helsinki University in Finland.
    Moen, Lars
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Thompson, Thomas
    SMHI.
    Jakobsson, Paul
    SMHI.
    Bleckert, Gunnar
    SMHI.
    Henriksson, Ann-Beate
    SMHI.
    Lindgren, Bo
    SMHI.
    Kållberg, Per
    SMHI, Forskningsavdelningen, Meteorologi.
    The Meteorological Auto Code (MAC) and Numerical Weather Prediction (NWP) at SMHI2016Rapport (Övrigt vetenskapligt)
    Abstract [sv]

    Sverige var ett föregångsland inom numeriska vädderprognoser och den allra första operativa väderprognosen gjordes redan 1954 på det Internationella Meteorologiska Institutet i Stockholm. SMHI kom igång senare, men 1961 startade man ett långsiktigt program för NWP (numerical weather prediction). Projektet växte gradvis under 1960-talet och blev så småningom en central komponent i SMHIs prognostjänst. En utmaning under de tidiga åren var de begränsade dataresurserna med primitiv programvara, och med dagens mått begränsat minnesutrymme och låg beräkningshastighet. För att kompensera dessa brister krävdes både beslutsamhet och ett stort mått av kreativitet. Som en central komponent i arbetet utvecklade NWP-gruppen datorsystemet MAC (Meteorological Auto Code) som här beskrivs i detalj samt också alla de beräkningsprogram som krävdes för prognostjänsten. Detta inkluderade olika prognosmodeller, analys samt program för databehandling och observationskontroll samt produktion av prognosresultaten i grafisk eller digital form.

    Det är vår förhoppning att f´öreliggande artikel skall ge den yngre generationen en inblick i hur det var att syssla med NWP under 1960-talet.

    Ladda ner fulltext (pdf)
    fulltext
  • 14.
    Bengtsson, Lisa
    et al.
    SMHI, Forskningsavdelningen, Meteorologi.
    Andrae, Ulf
    SMHI, Forskningsavdelningen, Meteorologi.
    Aspelien, Trygve
    SMHI.
    Batrak, Yurii
    Calvo, Javier
    de Rooy, Wim
    Gleeson, Emily
    Hansen-Sass, Bent
    Homleid, Mariken
    Hortal, Mariano
    Ivarsson, Karl-Ivar
    SMHI, Samhälle och säkerhet.
    Lenderink, Geert
    Niemelza, Sami
    Nielsen, Kristian Pagh
    Onvlee, Jeanette
    Rontu, Laura
    SMHI.
    Samuelsson, Patrick
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Santos Munoz, Daniel
    Subias, Alvaro
    Tijm, Sander
    Toll, Velle
    Yang, Xiaohua
    Koltzow, Morten Odegaard
    The HARMONIE-AROME Model Configuration in the ALADIN-HIRLAM NWP System2017Ingår i: Monthly Weather Review, ISSN 0027-0644, E-ISSN 1520-0493, Vol. 145, nr 5, s. 1919-1935Artikel i tidskrift (Refereegranskat)
  • 15.
    Bengtsson, Lisa
    et al.
    SMHI, Forskningsavdelningen, Meteorologi.
    Körnich, Heiner
    SMHI, Forskningsavdelningen, Meteorologi.
    Impact of a stochastic parametrization of cumulus convection, using cellular automata, in a mesoscale ensemble prediction system2016Ingår i: Quarterly Journal of the Royal Meteorological Society, ISSN 0035-9009, E-ISSN 1477-870X, Vol. 142, nr 695, s. 1150-1159Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A stochastic parametrization for deep convection, based on cellular automata, has been evaluated in the high-resolution (2.5 km) ensemble prediction system Hirlam Aladin Regional Mesoscale Operational NWP Ensemble Prediction System (HarmonEPS). We studied whether such a stochastic physical parametrization, whilst implemented in a deterministic forecast model, can have an impact on the performance of the uncertainty estimates given by an ensemble prediction system. Various feedback mechanisms in the parametrization were studied with respect to ensemble spread and skill, in both subgrid and resolved precipitation fields. It was found that the stochastic parametrization improves the model skill in general, by reducing a positive bias in precipitation. This reduction in bias, however, led to a reduction in ensemble spread of precipitation. Overall, scores that measure the accuracy and reliability of probabilistic predictions indicate that the net impact (improved skill, degraded spread) of the ensemble prediction system is improved for 6 h accumulated precipitation with the stochastic parametrization and is rather neutral for other quantities examined.

  • 16.
    Bengtsson, Lisa
    et al.
    SMHI, Forskningsavdelningen, Meteorologi.
    Körnich, Heiner
    SMHI, Forskningsavdelningen, Meteorologi.
    Kaellen, Erland
    Svensson, Gunilla
    Large-Scale Dynamical Response to Subgrid-Scale Organization Provided by Cellular Automata2011Ingår i: Journal of the Atmospheric Sciences, ISSN 0022-4928, E-ISSN 1520-0469, Vol. 68, nr 12, s. 3132-3144Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Because of the limited resolution of numerical weather prediction (NWP) models, subgrid-scale physical processes are parameterized and represented by gridbox means. However, some physical processes are better represented by a mean and its variance; a typical example is deep convection, with scales varying from individual updrafts to organized mesoscale systems. This study investigates, in an idealized setting, whether a cellular automaton (CA) can be used to enhance subgrid-scale organization by forming clusters representative of the convective scales and thus yield a stochastic representation of subgrid-scale variability. The authors study the transfer of energy from the convective to the larger atmospheric scales through nonlinear wave interactions. This is done using a shallow water (SW) model initialized with equatorial wave modes. By letting a CA act on a finer resolution than that of the SW model, it can be expected to mimic the effect of, for instance, gravity wave propagation on convective organization. Employing the CA scheme permits the reproduction of the observed behavior of slowing down equatorial Kelvin modes in convectively active regions, while random perturbations fail to feed back on the large-scale flow. The analysis of kinetic energy spectra demonstrates that the CA subgrid scheme introduces energy backscatter from the smallest model scales to medium scales. However, the amount of energy backscattered depends almost solely on the memory time scale introduced to the subgrid scheme, whereas any variation in spatial scales generated does not influence the energy spectra markedly.

  • 17.
    Bengtsson, Lisa
    et al.
    SMHI, Forskningsavdelningen, Meteorologi.
    Magnusson, Linus
    Källén, Erland
    Independent Estimations of the Asymptotic Variability in an Ensemble Forecast System2008Ingår i: Monthly Weather Review, ISSN 0027-0644, E-ISSN 1520-0493, Vol. 136, nr 11, s. 4105-4112Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    One desirable property within an ensemble forecast system is to have a one-to-one ratio between the root-mean-square error (rmse) of the ensemble mean and the standard deviation of the ensemble (spread). The ensemble spread and forecast error within the ECMWF ensemble prediction system has been extrapolated beyond 10 forecast days using a simple model for error growth. The behavior of the ensemble spread and the rmse at the time of the deterministic predictability are compared with derived relations of rmse at the infinite forecast length and the characteristic variability of the atmosphere in the limit of deterministic predictability. Utilizing this methodology suggests that the forecast model and the atmosphere do not have the same variability, which raises the question of how to obtain a perfect ensemble.

  • 18.
    Bengtsson, Lisa
    et al.
    SMHI, Forskningsavdelningen, Meteorologi.
    Steinheimer, Martin
    Bechtold, Peter
    Geleyn, Jean-Francois
    A stochastic parametrization for deep convection using cellular automata2013Ingår i: Quarterly Journal of the Royal Meteorological Society, ISSN 0035-9009, E-ISSN 1477-870X, Vol. 139, nr 675, s. 1533-1543Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A cellular automaton (CA) is introduced to the deep convection parametrization of the high-resolution limited-area model Aire Limitee Adaptation/Application de la Recherche a l'Operationnel (ALARO). The self-organizational characteristics of the CA allow for lateral communication between adjacent numerical weather prediction (NWP) model grid boxes and add additional memory to the deep convection scheme. The CA acts in two horizontal dimensions, with finer grid spacing than the NWP model. It is randomly seeded in regions where convective available potential energy (CAPE) exceeds a threshold value. Both deterministic and probabilistic rules, coupled to the large-scale wind, are explored to evolve the CA in time. Case studies indicate that the scheme has the potential to organize cells along convective squall lines and enhance advective effects. An ensemble of forecasts using the present CA scheme demonstrated an ensemble spread in the resolved wind field in regions where deep convection is large. Such a spread represents the uncertainty due to subgrid variability of deep convection and could be an interesting addition to an ensemble prediction system.

  • 19.
    Bengtsson, Lisa
    et al.
    SMHI, Forskningsavdelningen, Meteorologi.
    Tijm, Sander
    Vana, Filip
    Svensson, Gunilla
    Impact of Flow-Dependent Horizontal Diffusion on Resolved Convection in AROME2012Ingår i: Journal of Applied Meteorology and Climatology, ISSN 1558-8424, E-ISSN 1558-8432, Vol. 51, nr 1, s. 54-67Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Horizontal diffusion in numerical weather prediction models is, in general, applied to reduce numerical noise at the smallest atmospheric scales. In convection-permitting models, with horizontal grid spacing on the order of 1-3 km, horizontal diffusion can improve the model skill of physical parameters such as convective precipitation. For instance, studies using the convection-permitting Applications of Research to Operations at Mesoscale model (AROME) have shown an improvement in forecasts of large precipitation amounts when horizontal diffusion is applied to falling hydrometeors. The nonphysical nature of such a procedure is undesirable, however. Within the current AROME, horizontal diffusion is imposed using linear spectral horizontal diffusion on dynamical model fields. This spectral diffusion is complemented by nonlinear, flow-dependent, horizontal diffusion applied on turbulent kinetic energy, cloud water, cloud ice, rain, snow, and graupel. In this study, nonlinear flow-dependent diffusion is applied to the dynamical model fields rather than diffusing the already predicted falling hydrometeors. In particular, the characteristics of deep convection are investigated. Results indicate that, for the same amount of diffusive damping, the maximum convective updrafts remain strong for both the current and proposed methods of horizontal diffusion. Diffusing the falling hydrometeors is necessary to see a reduction in rain intensity, but a more physically justified solution can be obtained by increasing the amount of damping on the smallest atmospheric scales using the nonlinear, flow-dependent, diffusion scheme. In doing so, a reduction in vertical velocity was found, resulting in a reduction in maximum rain intensity.

  • 20.
    Bergström, Robert
    SMHI, Forskningsavdelningen, Meteorologi.
    Update and comparison of atmospheric chemistry mechanisms for the EMEP MSC-W model system: EmChem19a, EmChem19X, CRIv2R5Em, CB6r2Em, and MCMv3.3Em2022Rapport (Övrigt vetenskapligt)
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    Update and comparison of atmospheric chemistry mechanisms for the EMEP MSC-W model system
  • 21. Berner, Judith
    et al.
    Achatz, Ulrich
    Batte, Lauriane
    Bengtsson, Lisa
    SMHI, Forskningsavdelningen, Meteorologi.
    de la Camara, Alvaro
    Christensen, Hannah M.
    Colangeli, Matteo
    Coleman, Danielle R. B.
    Crommelin, Daaaan
    Dolaptchiev, Stamen I.
    Franzke, Christian L. E.
    Friederichs, Petra
    Imkeller, Peter
    Jarvinen, Heikki
    Juricke, Stephan
    Kitsios, Vassili
    Lott, Francois
    Lucarini, Valerio
    Mahajan, Salil
    Palmer, Timothy N.
    Penland, Cecile
    Sakradzija, Mirjana
    von Storch, Jin-Song
    Weisheimer, Antje
    Weniger, Michael
    Williams, Paul D.
    Yano, Jun-Ichi
    STOCHASTIC PARAMETERIZATION Toward a New View of Weather and Climate Models2017Ingår i: Bulletin of The American Meteorological Society - (BAMS), ISSN 0003-0007, E-ISSN 1520-0477, Vol. 98, nr 3, s. 565-587Artikel i tidskrift (Refereegranskat)
  • 22. Berntell, Ellen
    et al.
    Zhang, Qiong
    Chafik, Leon
    Körnich, Heiner
    SMHI, Forskningsavdelningen, Meteorologi.
    Representation of Multidecadal Sahel Rainfall Variability in 20th Century Reanalyses2018Ingår i: Scientific Reports, E-ISSN 2045-2322, Vol. 8, artikel-id 10937Artikel i tidskrift (Refereegranskat)
    Ladda ner fulltext (pdf)
    fulltext
  • 23. Blazica, V.
    et al.
    Gustafsson, Nils
    SMHI, Forskningsavdelningen, Meteorologi.
    Zagar, N.
    The impact of periodization methods on the kinetic energy spectra for limited-area numerical weather prediction models2015Ingår i: Geoscientific Model Development, ISSN 1991-959X, E-ISSN 1991-9603, Vol. 8, nr 1, s. 87-97Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The paper deals with the comparison of the most common periodization methods used to obtain spectral fields of limited-area models for numerical weather prediction. The focus is on the impact that the methods have on the spectra of the fields, which are used for verification and tuning of the models. A simplified model is applied with random fields that obey a known kinetic energy spectrum. The periodization methods under consideration are detrending, the discrete cosine transform and the application of an extension zone. For the extension zone, three versions are applied: the Boyd method, the ALADIN method and the HIRLAM method. The results show that detrending and the discrete cosine transform have little impact on the spectra, as does the Boyd method for extension zone. For the ALADIN and HIRLAM methods, the impact depends on the width of the extension zone - the wider the zone, the more artificial energy and the larger impact on the spectra. The width of the extension zone correlates to the modifications in the shape of the spectra as well as to the amplitudes of the additional energy in the spectra.

  • 24.
    Bojarova, Jelena
    et al.
    SMHI, Forskningsavdelningen, Meteorologi.
    Gustafsson, Nils
    SMHI, Forskningsavdelningen, Meteorologi.
    Relevance of climatological background error statistics for mesoscale data assimilation2019Ingår i: Tellus. Series A, Dynamic meteorology and oceanography, ISSN 0280-6495, E-ISSN 1600-0870, Vol. 71, nr 1, artikel-id 1615168Artikel i tidskrift (Refereegranskat)
    Ladda ner fulltext (pdf)
    fulltext
  • 25. Bojarova, Jelena
    et al.
    Gustafsson, Nils
    SMHI, Forskningsavdelningen, Meteorologi.
    Johansson, Åke
    SMHI, Forskningsavdelningen, Meteorologi.
    Vignes, Ole
    The ETKF rescaling scheme in HIRLAM2011Ingår i: Tellus. Series A, Dynamic meteorology and oceanography, ISSN 0280-6495, E-ISSN 1600-0870, Vol. 63, nr 3, s. 385-401Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The ETKF rescaling scheme has been implemented into the HIRLAM forecasting system in order to estimate the uncertainty of the model state. The main purpose is to utilize this uncertainty information for modelling of flow-dependent background error covariances within the framework of a hybrid variational ensemble data assimilation scheme. The effects of rank-deficiency in the ETKF formulation is explained and the need for variance inflation as a way to compensate for these effects is justified. A filter spin-up algorithm is proposed as a refinement of the variance inflation. The proposed spin-up algorithm will also act to prevent ensemble collapse since the ensemble will receive 'fresh blood' in the form of additional perturbation components, generated on the basis of a static background error covariance matrix. The resulting ETKF-based ensemble perturbations are compared with ensemble perturbations based on targeted singular vectors and are shown to have more realistic spectral characteristics.

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    fulltext
  • 26. Bolin, Karl
    et al.
    Almgren, Martin
    Olsson, Esbjörn
    SMHI, Forskningsavdelningen, Meteorologi.
    Karasalo, Ilkka
    Long term estimations of low frequency noise levels over water from an off-shore wind farm2014Ingår i: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 135, nr 3, s. 1106-1114Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This article focuses on computations of low frequency sound propagation from an off-shore wind farm. Two different methods for sound propagation calculations are combined with meteorological data for every 3 hours in the year 2010 to examine the varying noise levels at a reception point at 13 km distance. It is shown that sound propagation conditions play a vital role in the noise impact from the off-shore wind farm and ordinary assessment methods can become inaccurate at longer propagation distances over water. Therefore, this paper suggests that methodologies to calculate noise immission with realistic sound speed profiles need to be combined with meteorological data over extended time periods to evaluate the impact of low frequency noise from modern off-shore wind farms. (C) 2014 Acoustical Society of America.

  • 27. Boo, Sebastian
    et al.
    Ekman, Annica M. L.
    Svensson, Gunilla
    Devasthale, Abhay
    SMHI, Forskningsavdelningen, Meteorologi.
    Transport of Mineral Dust Into the Arctic in Two Reanalysis Datasets of Atmospheric Composition2023Ingår i: Tellus. Series B, Chemical and physical meteorology, ISSN 0280-6509, E-ISSN 1600-0889, Vol. 75, nr 1Artikel i tidskrift (Refereegranskat)
    Ladda ner fulltext (pdf)
    Transport of Mineral Dust Into the Arctic in Two Reanalysis Datasets of Atmospheric Composition
  • 28. Boone, Aaron
    et al.
    Samuelsson, Patrick
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Gollvik, Stefan
    SMHI, Forskningsavdelningen, Meteorologi.
    Napoly, Adrien
    Jarlan, Lionel
    Brun, Eric
    Decharme, Bertrand
    The interactions between soil-biosphere-atmosphere land surface model with a multi-energy balance (ISBA-MEB) option in SURFEXv8-Part 1: Model description2017Ingår i: Geoscientific Model Development, ISSN 1991-959X, E-ISSN 1991-9603, Vol. 10, nr 2, s. 843-872Artikel i tidskrift (Refereegranskat)
    Ladda ner fulltext (pdf)
    fulltext
  • 29. Borsche, M.
    et al.
    Kaiser-Weiss, A. K.
    Undén, Per
    SMHI, Forskningsavdelningen, Meteorologi.
    Kaspar, F.
    Methodologies to characterize uncertainties in regional reanalyses2015Ingår i: Advances in Science and Research, ISSN 1992-0628, E-ISSN 1992-0636, Vol. 12, s. 207-218Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    When using climate data for various applications, users are confronted with the difficulty to assess the uncertainties of the data. For both in-situ and remote sensing data the issues of representativeness, homogeneity, and coverage have to be considered for the past, and their respective change over time has to be considered for any interpretation of trends. A synthesis of observations can be obtained by employing data assimilation with numerical weather prediction (NWP) models resulting in a meteorological reanalysis. Global reanalyses can be used as boundary conditions for regional reanalyses (RRAs), which run in a limited area (Europe in our case) with higher spatial and temporal resolution, and allow for assimilation of more regionally representative observations. With the spatially highly resolved RRAs, which exhibit smaller scale information, a more realistic representation of extreme events (e.g. of precipitation) compared to global reanalyses is aimed for. In this study, we discuss different methods for quantifying the uncertainty of the RRAs to answer the question to which extent the smaller scale information (or resulting statistics) provided by the RRAs can be relied on. Within the European Union's seventh Framework Programme (EU FP7) project Uncertainties in Ensembles of Regional Re-Analyses (UERRA) ensembles of RRAs (both multi-model and single model ensembles) are produced and their uncertainties are quantified. Here we explore the following methods for characterizing the uncertainties of the RRAs: (A) analyzing the feedback statistics of the assimilation systems, (B) validation against station measurements and (C) grids derived thereof, and (D) against gridded satellite data products. The RRA ensembles (E) provide the opportunity to derive ensemble scores like ensemble spread and other special probabilistic skill scores. Finally, user applications (F) are considered. The various methods are related to user questions they can help to answer.

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    fulltext
  • 30.
    Bringfelt, Björn
    et al.
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Heikinheimo, M
    Gustafsson, Nils
    SMHI, Forskningsavdelningen, Meteorologi.
    Perov, Veniamin
    SMHI, Forskningsavdelningen, Meteorologi.
    Lindroth, A
    A new land-surface treatment for HIRLAM - comparisons with NOPEX measurements1999Ingår i: Agricultural and Forest Meteorology, ISSN 0168-1923, E-ISSN 1873-2240, Vol. 98-9, s. 239-256Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In order to improve the accuracy of forecasting near-surface atmospheric variables over a heterogeneous landscape, a framework of subgrid surface types and the ISBA parameterisation scheme for land surfaces have been tested in the operational weather forecast model HIRLAM, using a 5.5 km grid resolution. Surface energy fluxes measured during a single summer day at six fixed sites in the NOPEX area, representing agricultural fields, boreal forests and lakes, were used for verification. Both, in-situ field measurements and the HIRLAM simulation indicated that the Bowen ratio over forests was about twice as large as that of adjacent agricultural fields. This difference could be explained by the more effective turbulent mixing and larger surface resistance associated with the forest, thus making the sensible heat flux relatively large there. The use of initial soil moisture from a routine hydrological model gave improved agreement with measured surface fluxes and radiosonde temperature and humidity profiles compared to initialising from routine HIRLAM surface data. The differences in heat fluxes between the various surface types were also demonstrated by airborne flux measurements flown along a track at a height of ca. 100 m above the terrain. Modelled heat fluxes along the flight track were considerably smoothed due to the grid resolution used, e.g. the effect of a lake in reducing grid-averaged sensible heat flux could only be weakly detected, because the lake surface represented only 10% of the grid area. When the proportion of a contrasting surface type (lake) was altered from 10 to 100%, the surface fluxes calculated for the lake surface were almost unchanged; the results of the comparison did not provide evidence that more complex aggregation schemes for heat fluxes than straightforward area-weighted averaging would be required. The hourly variation of the modelled and simulated heat fluxes during the day studied could not be directly compared, because the simulated cloudiness did not exactly match that observed at the field sites. When the simulated net radiation was replaced with direct measurements, the model-based estimates of sensible and latent heat fluxes were closer to the corresponding field measurements. The divergence of sensible heat flux with height, as inferred from the tower measurements made over the forest, were supported by the aircraft measurements and the HIRLAM simulations. (C) 1999 Elsevier Science B.V. All rights reserved.

  • 31. Campana, P. E.
    et al.
    Lastanao, P.
    Zainali, S.
    Zhang, J.
    Landelius, Tomas
    SMHI, Forskningsavdelningen, Meteorologi.
    Melton, F.
    Towards an operational irrigation management system for Sweden with a water-food-energy nexus perspective2022Ingår i: Agricultural Water Management, ISSN 0378-3774, E-ISSN 1873-2283, Vol. 271, artikel-id 107734Artikel i tidskrift (Refereegranskat)
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    Towards an operational irrigation management system for Sweden with a water-food-energy nexus perspective
  • 32. Chen, Hans W.
    et al.
    Zhang, Qiong
    Körnich, Heiner
    SMHI, Forskningsavdelningen, Meteorologi.
    Chen, Deliang
    A robust mode of climate variability in the Arctic: The Barents Oscillation2013Ingår i: Geophysical Research Letters, ISSN 0094-8276, E-ISSN 1944-8007, Vol. 40, nr 11, s. 2856-2861Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Barents Oscillation (BO) is an anomalous wintertime atmospheric circulation pattern in the Northern Hemisphere that has been linked to the meridional flow over the Nordic Seas. There are speculations that the BO has important implications for the Arctic climate; however, it has also been suggested that the pattern is an artifact of Empirical Orthogonal Function (EOF) analysis due to an eastward shift of the Arctic Oscillation/North Atlantic Oscillation (AO/NAO). In this study, EOF analyses are performed to show that a robust pattern resembling the BO can be found during different time periods, even when the AO/NAO is relatively stationary. This BO has a high and stable temporal correlation with the geostrophic zonal wind over the Barents Sea, while the contribution from the AO/NAO is small. The surface air temperature anomalies over the Barents Sea are closely associated with this mode of climate variability.

  • 33. Clusius, Petri
    et al.
    Xavier, Carlton
    Pichelstorfer, Lukas
    Zhou, Putian
    Olenius, Tinja
    SMHI, Forskningsavdelningen, Meteorologi.
    Roldin, Pontus
    Boy, Michael
    Atmospherically Relevant Chemistry and Aerosol box model - ARCA box (version 1.2)2022Ingår i: Geoscientific Model Development, ISSN 1991-959X, E-ISSN 1991-9603, Vol. 15, nr 18, s. 7257-7286Artikel i tidskrift (Refereegranskat)
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    Atmospherically Relevant Chemistry and Aerosol box model - ARCA box (version 1.2)
  • 34. Cooper, Steven J.
    et al.
    L'Ecuyer, Tristan S.
    Wolff, Mareile Astrid
    Kuhn, Thomas
    Pettersen, Claire
    Wood, Norman B.
    Eliasson, Salomon
    SMHI, Forskningsavdelningen, Meteorologi.
    Schirle, Claire E.
    Shates, Julia
    Hellmuth, Franziska
    Engdahl, Bjorg Jenny Kokkvoll
    Vasquez-Martin, Sandra
    Ilmo, Trond
    Nygard, Knut
    Exploring Snowfall Variability through the High-Latitude Measurement of Snowfall (HiLaMS) Field Campaign2022Ingår i: Bulletin of The American Meteorological Society - (BAMS), ISSN 0003-0007, E-ISSN 1520-0477, Vol. 103, nr 8, s. E1762-E1780Artikel i tidskrift (Refereegranskat)
    Ladda ner fulltext (pdf)
    Exploring Snowfall Variability through the High-Latitude Measurement of Snowfall (HiLaMS) Field Campaign
  • 35. Cuxart, J
    et al.
    Holtslag, A A M
    Beare, R J
    Bazile, E
    Beljaars, A
    Cheng, A
    Conangla, L
    Ek, M
    Freedman, F
    Hamdi, R
    Kerstein, A
    Kitagawa, H
    Lenderink, G
    Lewellen, D
    Mailhot, J
    Mauritsen, T
    Perov, Veniamin
    SMHI, Forskningsavdelningen, Meteorologi.
    Schayes, G
    Steeneveld, G J
    Svensson, G
    Taylor, P
    Weng, W
    Wunsch, S
    Xu, K M
    Single-column model intercomparison for a stably stratified atmospheric boundary layer2006Ingår i: Boundary-layer Meteorology, ISSN 0006-8314, E-ISSN 1573-1472, Vol. 118, nr 2, s. 273-303Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The parameterization of the stably stratified atmospheric boundary layer is a difficult issue, having a significant impact on medium-range weather forecasts and climate integrations. To pursue this further, a moderately stratified Arctic case is simulated by nineteen single-column turbulence schemes. Statistics from a large-eddy simulation intercomparison made for the same case by eleven different models are used as a guiding reference. The single-column parameterizations include research and operational schemes from major forecast and climate research centres. Results from first-order schemes, a large number of turbulence kinetic energy closures, and other models were used. There is a large spread in the results; in general, the operational schemes mix over a deeper layer than the research schemes, and the turbulence kinetic energy and other higher-order closures give results closer to the statistics obtained from the large-eddy simulations. The sensitivities of the schemes to the parameters of their turbulence closures are partially explored.

  • 36.
    Dahlgren, Per
    et al.
    SMHI, Forskningsavdelningen, Meteorologi.
    Gustafsson, Nils
    SMHI, Forskningsavdelningen, Meteorologi.
    Assimilating host model information into a limited area model2012Ingår i: Tellus. Series A, Dynamic meteorology and oceanography, ISSN 0280-6495, E-ISSN 1600-0870, Vol. 64, artikel-id 15836Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We propose to add an extra source of information to the data-assimilation of the regional HIgh Resolution Limited Area Model (HIRLAM) model, constraining larger scales to the host model providing the lateral boundary conditions. An extra term, J(k), measuring the distance to the large-scale vorticity of the host model, is added to the cost-function of the variational data-assimilation. Vorticity is chosen because it is a good representative of the large-scale flow and because vorticity is a basic control variable of the HIRLAM variational data-assimilation. Furthermore, by choosing only vorticity, the remaining model variables, divergence, temperature, surface pressure and specific humidity will be allowed to adapt to the modified vorticity field in accordance with the internal balance constraints of the regional model. The error characteristics of the J(k) term are described by the horizontal spectral densities and the vertical eigenmodes (eigenvectors and eigenvalues) of the host model vorticity forecast error fields, expressed in the regional model geometry. The vorticity field, provided by the European Centre for Medium-range Weather Forecasts (ECMWF) operational model, was assimilated into the HIRLAM model during an experiment period of 33 d in winter with positive impact on forecast verification statistics for upper air variables and mean sea level pressure.

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    fulltext
  • 37.
    Dahlgren, Per
    et al.
    SMHI, Forskningsavdelningen, Meteorologi.
    Landelius, Tomas
    SMHI, Forskningsavdelningen, Atmosfärisk fjärranalys.
    Kållberg, Per
    SMHI, Forskningsavdelningen, Meteorologi.
    Gollvik, Stefan
    SMHI, Forskningsavdelningen, Meteorologi.
    A high-resolution regional reanalysis for Europe. Part 1: Three-dimensional reanalysis with the regional HIgh-Resolution Limited-Area Model (HIRLAM)2016Ingår i: Quarterly Journal of the Royal Meteorological Society, ISSN 0035-9009, E-ISSN 1477-870X, Vol. 142, nr 698, s. 2119-2131Artikel i tidskrift (Refereegranskat)
  • 38. Dee, D. P.
    et al.
    Uppala, S. M.
    Simmons, A. J.
    Berrisford, P.
    Poli, P.
    Kobayashi, S.
    Andrae, U.
    Balmaseda, M. A.
    Balsamo, G.
    Bauer, P.
    Bechtold, P.
    Beljaars, A. C. M.
    van de Berg, L.
    Bidlot, J.
    Bormann, N.
    Delsol, C.
    Dragani, R.
    Fuentes, M.
    Geer, A. J.
    Haimberger, L.
    Healy, S. B.
    Hersbach, H.
    Holm, E. V.
    Isaksen, L.
    Kållberg, Per
    SMHI, Forskningsavdelningen, Meteorologi.
    Koehler, M.
    Matricardi, M.
    McNally, A. P.
    Monge-Sanz, B. M.
    Morcrette, J. -J
    Park, B. -K
    Peubey, C.
    de Rosnay, P.
    Tavolato, C.
    Thepaut, J. -N
    Vitart, F.
    The ERA-Interim reanalysis: configuration and performance of the data assimilation system2011Ingår i: Quarterly Journal of the Royal Meteorological Society, ISSN 0035-9009, E-ISSN 1477-870X, Vol. 137, nr 656, s. 553-597Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    ERA-Interim is the latest global atmospheric reanalysis produced by the European Centre for Medium-Range Weather Forecasts (ECMWF). The ERA-Interim project was conducted in part to prepare for a new atmospheric reanalysis to replace ERA-40, which will extend back to the early part of the twentieth century. This article describes the forecast model, data assimilation method, and input datasets used to produce ERA-Interim, and discusses the performance of the system. Special emphasis is placed on various difficulties encountered in the production of ERA-40, including the representation of the hydrological cycle, the quality of the stratospheric circulation, and the consistency in time of the reanalysed fields. We provide evidence for substantial improvements in each of these aspects. We also identify areas where further work is needed and describe opportunities and objectives for future reanalysis projects at ECMWF. Copyright (C) 2011 Royal Meteorological Society

  • 39. Dersch, Juergen
    et al.
    Schroedter-Homscheidt, Marion
    Gairaa, Kacem
    Hanrieder, Natalie
    Landelius, Tomas
    SMHI, Forskningsavdelningen, Atmosfärisk fjärranalys.
    Lindskog, Magnus
    SMHI, Forskningsavdelningen, Meteorologi.
    Mueller, Stefan C.
    Santigosa, Lourdes Ramirez
    Sirch, Tobias
    Wilbert, Stefan
    Impact of DNI nowcasting on annual revenues of CSP plants for a time of delivery based feed in tariff2019Ingår i: Meteorologische Zeitschrift, ISSN 0941-2948, E-ISSN 1610-1227, Vol. 28, nr 3, s. 235-253Artikel i tidskrift (Refereegranskat)
    Ladda ner fulltext (pdf)
    fulltext
  • 40.
    Devasthale, Abhay
    et al.
    SMHI, Forskningsavdelningen, Meteorologi.
    Carlund, Thomas
    SMHI, Samhälle och säkerhet.
    Karlsson, Karl-Göran
    SMHI, Forskningsavdelningen, Meteorologi.
    Recent trends in the agrometeorological climate variables over Scandinavia2022Ingår i: Agricultural and Forest Meteorology, ISSN 0168-1923, E-ISSN 1873-2240, Vol. 316, artikel-id 108849Artikel i tidskrift (Refereegranskat)
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    Recent trends in the agrometeorological climate variables over Scandinavia
  • 41.
    Devasthale, Abhay
    et al.
    SMHI, Forskningsavdelningen, Meteorologi.
    Karlsson, Karl-Göran
    SMHI, Forskningsavdelningen, Oceanografi. SMHI, Forskningsavdelningen, Meteorologi.
    Decadal Stability and Trends in the Global Cloud Amount and Cloud Top Temperature in the Satellite-Based Climate Data Records2023Ingår i: Remote Sensing, E-ISSN 2072-4292, Vol. 15, nr 15, artikel-id 3819Artikel i tidskrift (Refereegranskat)
  • 42.
    Devasthale, Abhay
    et al.
    SMHI, Forskningsavdelningen, Meteorologi.
    Karlsson, Karl-Göran
    SMHI, Forskningsavdelningen, Meteorologi.
    Andersson, Sandra
    SMHI, Samhällsplanering.
    Engström, Erik
    SMHI, Samhällsplanering.
    Difference between WMO Climate Normal and Climatology: Insights from a Satellite-Based Global Cloud and Radiation Climate Data Record2023Ingår i: Remote Sensing, E-ISSN 2072-4292, Vol. 15, nr 23, artikel-id 5598Artikel i tidskrift (Refereegranskat)
    Ladda ner fulltext (pdf)
    Difference between WMO Climate Normal and Climatology: Insights from a Satellite-Based Global Cloud and Radiation Climate Data Record
  • 43. Edlund, Karl Kilbo
    et al.
    Sallsten, Gerd
    Molnar, Peter
    Andersson, Eva M.
    Ogren, Mikael
    Segersson, David
    SMHI, Forskningsavdelningen, Meteorologi.
    Fagman, Erika
    Fagerberg, Bjorn
    Barregard, Lars
    Bergstrom, Goran
    Stockfelt, Leo
    Long-term exposure to air pollution, coronary artery calcification, and carotid artery plaques in the population-based Swedish SCAPIS Gothenburg cohort2022Ingår i: Environmental Research, ISSN 0013-9351, E-ISSN 1096-0953, Vol. 214, artikel-id 113926Artikel i tidskrift (Refereegranskat)
    Ladda ner fulltext (pdf)
    Long-term exposure to air pollution, coronary artery calcification, and carotid artery plaques in the population-based Swedish SCAPIS Gothenburg cohort
  • 44. Eichler, Anja
    et al.
    Legrand, Michel
    Jenk, Theo M.
    Preunkert, Susanne
    Andersson, Camilla
    SMHI, Forskningsavdelningen, Meteorologi.
    Eckhardt, Sabine
    Engardt, Magnuz
    Plach, Andreas
    Schwikowski, Margit
    Consistent histories of anthropogenic western European air pollution preserved in different Alpine ice cores2023Ingår i: The Cryosphere, ISSN 1994-0416, E-ISSN 1994-0424, Vol. 17, nr 5, s. 2119-2137Artikel i tidskrift (Refereegranskat)
    Ladda ner fulltext (pdf)
    Consistent histories of anthropogenic western European air pollution preserved in different Alpine ice cores
  • 45. Elkadeem, Mohamed R.
    et al.
    Zainali, Sebastian
    Lu, Silvia Ma
    Younes, Ali
    Abido, Mohamed A.
    Amaducci, Stefano
    Croci, Michele
    Zhang, Jie
    Landelius, Tomas
    SMHI, Forskningsavdelningen, Meteorologi.
    Stridh, Bengt
    Campana, Pietro Elia
    Agrivoltaic systems potentials in Sweden: A geospatial-assisted multi-criteria analysis2024Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 356, artikel-id 122108Artikel i tidskrift (Refereegranskat)
  • 46. El-Said, A.
    et al.
    Brousseau, P.
    Ridal, Martin
    SMHI, Forskningsavdelningen, Meteorologi.
    Randriamampianina, R.
    Towards Full Flow-Dependence: New Temporally Varying EDA Quotient Functionality to Estimate Background Errors in CERRA2022Ingår i: Journal of Advances in Modeling Earth Systems, ISSN 1942-2466, Vol. 14, nr 2, artikel-id e2021MS002637Artikel i tidskrift (Refereegranskat)
    Ladda ner fulltext (pdf)
    Towards Full Flow-Dependence: New Temporally Varying EDA Quotient Functionality to Estimate Background Errors in CERRA
  • 47. Fortelius, C
    et al.
    Andrae, Ulf
    SMHI, Forskningsavdelningen, Meteorologi.
    Forsblom, M
    The BALTEX regional reanalysis project2002Ingår i: Boreal environment research, ISSN 1239-6095, E-ISSN 1797-2469, Vol. 7, nr 3, s. 193-201Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The BALTEX regional reassimilation project uses meteorological data assimilation for quantifying the climatic energy and water cycles over the catchment basin of the Baltic Sea during the course of one annual cycle, Sep. 1999-Oct. 2000. This report presents the data assimilation system used, the available products, and a sample of preliminary results. The latter demonstrate that the system is capable of simulating the essential features of the energy and water cycles of the Baltic drainage basin. We find this encouraging, because the model has not been tuned to reproduce these cycles, but mainly to predict the atmospheric state.

  • 48. FRANZEN, LG
    et al.
    HJELMROOS, M
    Kållberg, Per
    SMHI, Forskningsavdelningen, Meteorologi.
    BRORSTROMLUNDEN, E
    JUNTTO, S
    SAVOLAINEN, AL
    THE YELLOW-SNOW EPISODE OF NORTHERN FENNOSCANDIA, MARCH-1991 - A CASE-STUDY OF LONG-DISTANCE TRANSPORT OF SOIL, POLLEN AND STABLE ORGANIC-COMPOUNDS1994Ingår i: Atmospheric Environment, ISSN 1352-2310, E-ISSN 1873-2844, Vol. 28, nr 22, s. 3587-3604Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The present paper describes a vast dustfall with snow in northern Fennoscandia, 10 March 1991. The area affected by dust deposition was at least 320,000 km(2). and the particulate mass received amounted to between 50 and 200 mg m(-2). The total amounts of dust deposited in the investigated area sum up to approximately 50,000 tonnes. The dust consisted of soil particles, i.e. single mineral grains and loose ferric aggregates of mineral grains in addition to pollen and spores. Mineralogically, the dust was dominated by small rounded quartz grains. Median size of the dust particles was 2.72 mu m. The total pollen concentration varied from 327 to 1172 pollen cm(-2). The pollen types identified were divided in ''Nordic/Central European'' taxa and ''Exotic'' taxa. Pollen from the former group, e.g. Betula, Alnus and Corylus were believed to originate in the Alps and in the northern parts of Central Europe where these species were flowering. The latter category was considered to originate in more remote areas, many of them belonging to the taxa growing only around the Mediterranean. From a paleo-ecological point of view, long-distance transport such as this would count for an important potential source of error whenever interpreting Holocene pollen diagrams. The content of stable organic compounds showed that the dust was relatively clean, compared to other episodes, when the dust deposited had originated in heavily polluted regions. The small amounts of chlorinated hydrocarbons, polychlorinated biphenyles (PCB), polyaromated hydrocarbons (PAH) and other hydrocarbons found, are believed to have been adsorbed by the particle surfaces during transportation. The results of the study, along with meteorological data, lead to the conclusion that the material originated in North Africa. Dust mobilization was reported in Tunisia as well as in Algeria. This means that the dust was transported at least 7000 km before deposition.

  • 49. Frogner, Inger-Lise
    et al.
    Andrae, Ulf
    SMHI, Forskningsavdelningen, Meteorologi.
    Bojarova, Jelena
    SMHI, Forskningsavdelningen, Meteorologi.
    Callado, Alfons
    Escriba, Pau
    Feddersen, Henrik
    Hally, Alan
    Kauhanen, Janne
    Randriamampianina, Roger
    Singleton, Andrew
    Smet, Geert
    Van Der Veen, Sibbo
    Vignes, Ole
    HarmonEPS-The HARMONIE Ensemble Prediction System2019Ingår i: Weather and forecasting, ISSN 0882-8156, E-ISSN 1520-0434, Vol. 34, nr 6, s. 1909-1937Artikel i tidskrift (Refereegranskat)
    Ladda ner fulltext (pdf)
    fulltext
  • 50. FROGNER, INGER-LISE
    et al.
    Andrae, Ulf
    SMHI, Forskningsavdelningen, Meteorologi.
    OLLINAHO, P. I. R. K. K. A.
    HALLY, A. L. A. N.
    HAMALAINEN, K. A. R. O. L. I. I. N. A.
    KAUHANEN, J. A. N. N. E.
    Ivarsson, Karl-Ivar
    SMHI, Samhälle och säkerhet.
    Yazgi, Daniel
    SMHI, Forskningsavdelningen, Meteorologi.
    Model Uncertainty Representation in a Convection-Permitting Ensemble-SPP and SPPT in HarmonEPS2022Ingår i: Monthly Weather Review, ISSN 0027-0644, E-ISSN 1520-0493, Vol. 150, nr 4, s. 775-795Artikel i tidskrift (Refereegranskat)
    Ladda ner fulltext (pdf)
    Model Uncertainty Representation in a Convection-Permitting Ensemble—SPP and SPPT in HarmonEPS
1234 1 - 50 av 185
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