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  • 1. Aas, W.
    et al.
    Tsyro, S.
    Bieber, E.
    Bergström, Robert
    SMHI, Research Department, Air quality.
    Ceburnis, D.
    Ellermann, T.
    Fagerli, H.
    Froelich, M.
    Gehrig, R.
    Makkonen, U.
    Nemitz, E.
    Otjes, R.
    Perez, N.
    Perrino, C.
    Prevot, A. S. H.
    Putaud, J. -P
    Simpson, D.
    Spindler, G.
    Vana, M.
    Yttri, K. E.
    Lessons learnt from the first EMEP intensive measurement periods2012In: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 12, no 17, p. 8073-8094Article in journal (Refereed)
    Abstract [en]

    The first EMEP intensive measurement periods were held in June 2006 and January 2007. The measurements aimed to characterize the aerosol chemical compositions, including the gas/aerosol partitioning of inorganic compounds. The measurement program during these periods included daily or hourly measurements of the secondary inorganic components, with additional measurements of elemental- and organic carbon (EC and OC) and mineral dust in PM1, PM2.5 and PM10. These measurements have provided extended knowledge regarding the composition of particulate matter and the temporal and spatial variability of PM, as well as an extended database for the assessment of chemical transport models. This paper summarise the first experiences of making use of measurements from the first EMEP intensive measurement periods along with EMEP model results from the updated model version to characterise aerosol composition. We investigated how the PM chemical composition varies between the summer and the winter month and geographically. The observation and model data are in general agreement regarding the main features of PM10 and PM2.5 composition and the relative contribution of different components, though the EMEP model tends to give slightly lower estimates of PM10 and PM2.5 compared to measurements. The intensive measurement data has identified areas where improvements are needed. Hourly concurrent measurements of gaseous and particulate components for the first time facilitated testing of modelled diurnal variability of the gas/aerosol partitioning of nitrogen species. In general, the modelled diurnal cycles of nitrate and ammonium aerosols are in fair agreement with the measurements, but the diurnal variability of ammonia is not well captured. The largest differences between model and observations of aerosol mass are seen in Italy during winter, which to a large extent may be explained by an underestimation of residential wood burning sources. It should be noted that both primary and secondary OC has been included in the calculations for the first time, showing promising results. Mineral dust is important, especially in southern Europe, and the model seems to capture the dust episodes well. The lack of measurements of mineral dust hampers the possibility for model evaluation for this highly uncertain PM component. There are also lessons learnt regarding improved measurements for future intensive periods. There is a need for increased comparability between the measurements at different sites. For the nitrogen compounds it is clear that more measurements using artefact free methods based on continuous measurement methods and/or denuders are needed. For EC/OC, a reference methodology (both in field and laboratory) was lacking during these periods giving problems with comparability, though measurement protocols have recently been established and these should be followed by the Parties to the EMEP Protocol. For measurements with no defined protocols, it might be a good solution to use centralised laboratories to ensure comparability across the network. To cope with the introduction of these new measurements, new reporting guidelines have been developed to ensure that all proper information about the methodologies and data quality is given.

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  • 2.
    Ambjörn, Cecilia
    et al.
    SMHI, Professional Services.
    Gidhagen, Lars
    SMHI, Research Department, Air quality.
    Vatten- och materialtransporter mellan bottniska viken och Östersjön1979Report (Other academic)
    Abstract [en]

    Within the framework of the Swedish-Finnish Joint Cornmitte on the Gulf of Bothnia, investigations have been carried out in the Åland Sea and in the Finnish Archipelago Sea in order to study water exchange and transports of heat and nutrients between the Gulf of Bothnia and the Baltic proper. The work has been a cooperation between the Swedish Meteorological and Hydrological Institute (SMHI) and the Finnish Institute of Marine Research. Measurements have been performed by SMHI during the periods June-December 1973, July-December 1974, August 1975-May 1976 and June- August 1977, most intensively in 1974 and 1977. The following parameters have been measured: current speed and direction, water temperature, salinity, oxyge , total phosphorus and total nitrogen.

    The current patterns in the northern part of the Åland Sea are described .An expansion of the north- south current components into empirical orthogonal functions shows the main characteristics of the current systems. The mean circulation during thermally stratified conditions shows southgoing currents in the upper layer and northgoing in the lower. A simple numerical model shows that the main driving force on the net current, when the vertical stratificationis weak, is the surface slope along the channel. Local acceleration and bottom friction are also important.

    Water transports have been calculated from the current measurements.The water exchange is most probably largest during the autumn. In the surnmer of 1977 measurements were made on both sides of Åland. The net transport was southgoing in the Åland Sea (46-95 km3 month- l to the north and 78-236 to the south) and northgoing in the Archipelago Sea (28-44 km3 • month- l to the north and 14-31 to the south) . Comparing the net exchange between the central Baltic and the Gulf of Bothnia with the volume changes in the latter , determined from water level records , gives a difference that probably depends on the choice of representative areas for the current meters. Calculations of transports of total phosphorus, total nitrogen and heat have also been made.

    English translations of captions to figures and tables are found in appendix 11 (the last pages of this report).

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    Vatten- och materialtransporter mellan bottniska viken och Östersjön
  • 3.
    Amorim, Jorge Humberto
    et al.
    SMHI, Research Department, Air quality.
    Asker, Christian
    SMHI, Research Department, Air quality.
    Belusic, Danijel
    SMHI, Research Department, Climate research - Rossby Centre.
    Carvalho, Ana
    SMHI, Research Department, Air quality.
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    Gidhagen, Lars
    SMHI, Research Department, Air quality.
    Hundecha, Yeshewatesfa
    SMHI, Research Department, Hydrology.
    Körnich, Heiner
    SMHI, Research Department, Meteorology.
    Lind, Petter
    SMHI, Research Department, Climate research - Rossby Centre.
    Olsson, Esbjörn
    SMHI, Research Department, Meteorology.
    Olsson, Jonas
    SMHI, Research Department, Hydrology.
    Segersson, David
    SMHI, Research Department, Air quality.
    Strombäck, Lena
    SMHI, Research Department, Hydrology.
    Joe, Paul
    Baklanov, Alexander
    Integrated Urban Services for European cities: the Stockholm case2018In: WMO Bulletin, ISSN 0042-9767, Vol. 67, no 2, p. 33-40Article in journal (Refereed)
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  • 4.
    Amorim, Jorge Humberto
    et al.
    SMHI, Research Department, Air quality.
    Engardt, Magnuz
    Johansson, Christer
    Ribeiro, Isabel
    SMHI, Research Department, Air quality.
    Sannebro, Magnus
    Regulating and Cultural Ecosystem Services of Urban Green Infrastructure in the Nordic Countries: A Systematic Review2021In: International Journal of Environmental Research and Public Health, ISSN 1661-7827, E-ISSN 1660-4601, Vol. 18, no 3, article id 1219Article in journal (Refereed)
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  • 5.
    Amorim, Jorge Humberto
    et al.
    SMHI, Research Department, Air quality.
    Segersson, David
    SMHI, Research Department, Air quality.
    Körnich, Heiner
    SMHI, Research Department, Meteorology.
    Asker, Christian
    SMHI, Research Department, Air quality.
    Olsson, Esbjörn
    SMHI, Research Department, Meteorology.
    Gidhagen, Lars
    SMHI, Research Department, Air quality.
    High resolution simulation of Stockholm's air temperature and its interactions with urban development2020In: Urban Climate, E-ISSN 2212-0955, Vol. 32, article id 100632Article in journal (Refereed)
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  • 6.
    Amorim, Jorge Humberto
    et al.
    SMHI, Research Department, Air quality.
    Valente, J.
    Cascao, P.
    Ribeiro, L. M.
    Viegas, D. X.
    Ottmar, R.
    Miranda, A. I.
    Near-source grid-based measurement of CO and PM2.5 concentration during a full-scale fire experiment in southern European shrubland2016In: Atmospheric Environment, ISSN 1352-2310, E-ISSN 1873-2844, Vol. 145, p. 19-28Article in journal (Refereed)
  • 7.
    Andersson, Camilla
    et al.
    SMHI, Research Department, Air quality.
    Alpfjord, Helene
    SMHI, Professional Services.
    Robertson, Lennart
    SMHI, Research Department, Air quality.
    Karlsson, Per Erik
    Miljöforskningsinstitutet.
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    Reanalysis of and attribution to near-surface ozone concentrations in Sweden during 1990-20132017In: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 17, no 22Article in journal (Refereed)
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  • 8.
    Andersson, Camilla
    et al.
    SMHI, Research Department, Air quality.
    Alpfjord Wylde, Helene
    SMHI, Professional Services.
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    Long-term sulfur and nitrogen deposition in Sweden: 1983-2013 reanalysis2018Report (Other academic)
    Abstract [en]

    A unique long-term (1983-2013) dataset of sulfur and nitrogen deposition has been compiled for Sweden as well as the Baltic Sea and surrounding countries, based on quality controlled measurements and modelled fields, fused though advanced methods capturing spatial and temporal variations. The data set can be used for describing trends in deposition to various relevant surface types.Our reanalysis compares well to observations, but we have identified differences in dry deposition to coniferous forest. This calls for more in-depth studies of the dry deposition and improvements to the respective methods.We recommend more advanced methods of describing spatial variation than averaging or spatial interpolation of observed deposition.We estimate a significant decrease from the 1980s until today for both sulfur and nitrogen deposition (by ca. 80% and 30% respectively).Critical loads for coniferous and deciduous forests, mountain vegetation and wetlands have been surpassed mainly in the southwest Sweden, but also in southeast Sweden and the southern parts of Scandes Mountains. The situation is improving, but exceedances do still occur also in larger regions.

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  • 9.
    Andersson, Camilla
    et al.
    SMHI, Research Department, Air quality.
    Andersson, Stefan
    SMHI, Research Department, Air quality.
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Segersson, David
    SMHI, Research Department, Air quality.
    Halter och deposition av luftföroreningar: Förändring över Sverige från 2010 till 2020 i bidrag från Sverige, Europa och Internationell Sjöfart2011Report (Other academic)
    Abstract [sv]

    I denna studie presenteras nutid (2010) och förändring till framtid (2020) för ett emissionsscenario baserat på PRIMES energimodell och IMO-beslut för internationell sjöfart. Utifrån dessa uppskattningar har modellberäkningar gjorts över nutid och förändring till 2020 för deposition av kväve och svavel, samt för lufthalter av sekundära inorganiska aerosoler (SIA; partiklar) och marknära ozon. Bidrag och förändring i detta bidrag till 2020 har presenterats för internationell sjöfart. Även Sveriges och övriga Europas bidrag till deposition i nutid och förändring till framtid har presenterats.Huvudresultaten i studien är:- Landbaserade utsläpp av svaveldioxid, kväveoxider, partiklar, kolmonoxid och volatila organiska ämnen förväntas minska i Europa såväl som i Sverige, medan utsläppen av ammoniak förväntas öka till 2020 i Europa.- Internationell sjöfart förväntas minska sina utsläpp av svaveldioxid på grund av IMO-beslut, men förväntad ökning i trafiken medför ökade utsläpp av NOx.- Såväl deposition som lufthalter fortsätter vara högst i södra Sverige.- Utsläppsminskningarna till 2020 medför minskat nedfall av svavel och kväve i Sverige.- Bidraget till kvävedeposition från internationell sjöfart ökar i hela landet till 2020, övriga bidrag minskar.- Luftkvaliteten i regional bakgrundsluft i Sverige förbättras för såväl marknära ozon som för SIA.- De högsta halterna av marknära ozon beräknas minska som en följd av utsläppsminskningar i Europa.

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  • 10.
    Andersson, Camilla
    et al.
    SMHI, Research Department, Air quality.
    Bergström, Robert
    SMHI, Research Department, Air quality.
    Bennet, Cecilia
    SMHI, Research Department, Air quality.
    Robertson, Lennart
    SMHI, Research Department, Air quality.
    Thomas, Manu
    SMHI, Research Department, Air quality.
    Korhonen, H.
    Lehtinen, K. E. J.
    Kokkola, H.
    MATCH-SALSA - Multi-scale Atmospheric Transport and CHemistry model coupled to the SALSA aerosol microphysics model - Part 1: Model description and evaluation2015In: Geoscientific Model Development, ISSN 1991-959X, E-ISSN 1991-9603, Vol. 8, no 2, p. 171-189Article in journal (Refereed)
    Abstract [en]

    We have implemented the sectional aerosol dynamics model SALSA (Sectional Aerosol module for Large Scale Applications) in the European-scale chemistry-transport model MATCH (Multi-scale Atmospheric Transport and Chemistry). The new model is called MATCH-SALSA. It includes aerosol microphysics, with several formulations for nucleation, wet scavenging and condensation. The model reproduces observed higher particle number concentration (PNC) in central Europe and lower concentrations in remote regions. The modeled PNC size distribution peak occurs at the same or smaller particle size as the observed peak at four measurement sites spread across Europe. Total PNC is underestimated at northern and central European sites and accumulation-mode PNC is underestimated at all investigated sites. The low nucleation rate coefficient used in this study is an important reason for the underestimation. On the other hand, the model performs well for particle mass (including secondary inorganic aerosol components), while elemental and organic carbon concentrations are underestimated at many of the sites. Further development is needed, primarily for treatment of secondary organic aerosol, in terms of biogenic emissions and chemical transformation. Updating the biogenic secondary organic aerosol (SOA) scheme will likely have a large impact on modeled PM2.5 and also affect the model performance for PNC through impacts on nucleation and condensation.

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  • 11.
    Andersson, Camilla
    et al.
    SMHI, Research Department, Air quality.
    Bergström, Robert
    SMHI, Research Department, Air quality.
    Bennet, Cecilia
    SMHI, Research Department, Air quality.
    Thomas, Manu
    SMHI, Research Department, Air quality.
    Robertson, Lennart
    SMHI, Research Department, Air quality.
    Kokkola, Harri
    FMI.
    Lehtinen, Kari
    FMI.
    MATCH-SALSA: Multi-scale Atmospheric Transport and CHemistry model coupled to the SALSA aerosol microphysics model2013Report (Other academic)
    Abstract [en]

    This report presents a new aerosol dynamics version of a European scale Eulerian CTM, MATCH. The new model is called MATCH-SALSA, and includes aerosol microphysics and several options for nucleation, wet scavenging and condensation. The report entails model description, evaluation and sensitivity tests.The new model reproduces observed higher particle number concentration (PNC) in central Europe and lower in remote regions. The model peak PNC occurs at the same particle size as the observed peak or at smaller sizes, which indicate missing growth. Total PNC is underestimated at some sites. The model performs well for particle mass, including SIA components. EC and OC are underestimated at many of the sites.The results are sensitive to the fraction of SOx emitted as H2SO4 and the optimum choice is site dependent. The model results are highly sensitive to whether organic nucleation is included or not. The model results are sensitive to amount of organic vapors in the condensation. The model can be used in applications knowing the restrictions of what the model manages well and what needs further improvements, which is detailed in the report.

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  • 12.
    Andersson, Camilla
    et al.
    SMHI, Research Department, Air quality.
    Bergström, Robert
    SMHI, Research Department, Air quality.
    Johansson, Christer
    Population exposure and mortality due to regional background PM in Europe - Long-term simulations of source region and shipping contributions2009In: Atmospheric Environment, ISSN 1352-2310, E-ISSN 1873-2844, Vol. 43, no 22-23, p. 3614-3620Article in journal (Refereed)
    Abstract [en]

    This paper presents the contribution to population exposure (PE) of regional background fine primary (PPM(2.5)) and secondary inorganic (SIA) particulate matter and its impact on mortality in Europe during 1997-2003 calculated with a chemistry transport model. Contributions to concentrations and PE due to emissions from shipping, Western (WEU), Eastern (EEU), and Northern Europe are compared. WEU contributes about 40% to both PPM(2.5) and SIA concentrations, whereas the EEU contribution to PPM(2.5) is much higher (43% of total PPM(2.5)) than to SIA (29% of total SIA). The population weighted average concentration (PWC) of PPM(2.5) is a factor of 2.3 higher than average (non-weighted) concentrations, whereas for SIA the PWC is only a factor 1.6 higher. This is due to PPM(2.5) concentrations having larger gradients and being relatively high over densely populated areas, whereas SIA is formed outside populated areas. WEU emissions contribute relatively more than EEU to PWC and mortality due to both PPM(2.5) and SIA in Europe. The number of premature deaths in Europe is estimated to 301000 per year due to PPM(2.5) exposure and 245 000 due to SIA, despite 3.3 times higher average SIA concentrations. This is due to population weighting and assumed (and uncertain) higher relative risk of mortality for PPM(2.5) components (2.8 times higher RR for PPM(2.5)). This study indicates that it might be more efficient, for the health of the European population, to decrease primary PM emissions (especially in WEU) than to decrease precursors of SIA, but more knowledge on the toxicity of different PM constituents is needed before firm conclusions can be drawn. (C) 2009 Elsevier Ltd. All rights reserved.

  • 13.
    Andersson, Camilla
    et al.
    SMHI, Research Department, Air quality.
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    European ozone in a future climate: Importance of changes in dry deposition and isoprene emissions2010In: Journal of Geophysical Research - Atmospheres, ISSN 2169-897X, E-ISSN 2169-8996, Vol. 115, article id D02303Article in journal (Refereed)
    Abstract [en]

    Projections of future surface ozone over Europe conducted utilizing chemistry transport models (CTMs) coupled to climate models differ greatly, even in sign. CTM sensitivity studies were conducted in order to investigate the importance of changes in natural isoprene emissions and dry deposition to vegetation, both coupled to meteorology. This knowledge can be used to improve surface ozone projections. Our simulations suggest climate change over Europe would cause changes in surface ozone between -4.0 to +13 ppb(v) on average (April-September) and -3.5 to +25 ppb(v) on average (April-September) daily maximum from 1961 - 1990 to 2071 - 2100. The change is positive in the southwest and negative in the north. The isoprene emissions increased by a factor of about 1.8 from 1961 - 1990 to 2071 - 2100. A rescaling of isoprene emissions shows that the large increase in isoprene emission is of importance (0 - 30% of the change in surface ozone) in central, southern, and western Europe. The use of a formulation for ozone dry deposition to vegetation, dependent on meteorology, and changes in snow cover, affecting the dry deposition, are more important processes. The changes in dry deposition to vegetation (not including changes in aerodynamic resistance) explain up to 80% of the surface ozone change in Spain. Therefore it is vital to include meteorological dependence for dry deposition of ozone to vegetation in surface ozone projections. Isoprene emissions are of less importance, but they are nonnegligible and should definitely be emitted online in climate ozone projection studies.

  • 14.
    Andersson, Camilla
    et al.
    SMHI, Research Department, Air quality.
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Bergström, Robert
    SMHI, Research Department, Air quality.
    Interannual variation and trends in air pollution over Europe due to climate variability during 1958-2001 simulated with a regional CTM coupled to the ERA40 reanalysis2007In: Tellus. Series B, Chemical and physical meteorology, ISSN 0280-6509, E-ISSN 1600-0889, Vol. 59, no 1, p. 77-98Article in journal (Refereed)
    Abstract [en]

    A three-dimensional Chemistry Transport Model was used to study the meteorologically induced interannual variability and trends in deposition of sulphur and nitrogen as well as concentrations of surface ozone (O(3)), nitrogen dioxide (NO(2)) and particulate matter (PM) and its constituents over Europe during 1958-2001. The model was coupled to the meteorological reanalysis ERA40, produced at the European Centre for Medium-range Weather Forecasts. Emissions and boundary conditions of chemical compounds and PM were kept constant at present levels. The average European interannual variation, due to meteorological variability, ranges from 3% for O(3), 5% for NO(2), 9% for PM, 6-9% for dry deposition, to about 20% for wet deposition of sulphur and nitrogen. For the period 1979-2001 the trend in ozone, due to climate variability is increasing in central and southwestern Europe and decreasing in northeastern Europe, the trend in NO(2) is approximately opposite. The trend in PM is positive in eastern Europe. There are negative trends in wet deposition in southwestern and central Europe and positive trends in dry deposition overall. A bias in ERA40 precipitation could be partly responsible for the trends. The variation and trends need to be considered when interpreting measurements and designing measurement campaigns.

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  • 15. Andersson, E.
    et al.
    Kahnert, Michael
    SMHI, Research Department, Air quality.
    Devasthale, Abhay
    SMHI, Research Department, Atmospheric remote sensing.
    Methodology for evaluating lateral boundary conditions in the regional chemical transport model MATCH (v5.5.0) using combined satellite and ground-based observations2015In: Geoscientific Model Development, ISSN 1991-959X, E-ISSN 1991-9603, Vol. 8, no 11, p. 3747-3763Article in journal (Refereed)
    Abstract [en]

    Hemispheric transport of air pollutants can have a significant impact on regional air quality, as well as on the effect of air pollutants on regional climate. An accurate representation of hemispheric transport in regional chemical transport models (CTMs) depends on the specification of the lateral boundary conditions (LBCs). This study focuses on the methodology for evaluating LBCs of two moderately long-lived trace gases, carbon monoxide (CO) and ozone (O-3), for the European model domain and over a 7-year period, 2006-2012. The method is based on combining the use of satellite observations at the lateral boundary with the use of both satellite and in situ ground observations within the model domain. The LBCs are generated by the global European Monitoring and Evaluation Programme Meteorological Synthesizing Centre - West (EMEP MSC-W) model; they are evaluated at the lateral boundaries by comparison with satellite observations of the Terra-MOPITT (Measurements Of Pollution In The Troposphere) sensor (CO) and the Aura-OMI (Ozone Monitoring Instrument) sensor (O-3). The LBCs from the global model lie well within the satellite uncertainties for both CO and O-3. The biases increase below 700 hPa for both species. However, the satellite retrievals below this height are strongly influenced by the a priori data; hence, they are less reliable than at, e.g. 500 hPa. CO is, on average, underestimated by the global model, while O-3 tends to be overestimated during winter, and underestimated during summer. A regional CTM is run with (a) the validated monthly climatological LBCs from the global model; (b) dynamical LBCs from the global model; and (c) constant LBCs based on in situ ground observations near the domain boundary. The results are validated against independent satellite retrievals from the Aqua-AIRS (Atmospheric InfraRed Sounder) sensor at 500 hPa, and against in situ ground observations from the Global Atmospheric Watch (GAW) network. It is found that (i) the use of LBCs from the global model gives reliable in-domain results for O-3 and CO at 500 hPa. Taking AIRS retrievals as a reference, the use of these LBCs substantially improves spatial pattern correlations in the free troposphere as compared to results obtained with fixed LBCs based on ground observations. Also, the magnitude of the bias is reduced by the new LBCs for both trace gases. This demonstrates that the validation methodology based on using satellite observations at the domain boundary is sufficiently robust in the free troposphere. (ii) The impact of the LBCs on ground concentrations is significant only at locations in close proximity to the domain boundary. As the satellite data near the ground mainly reflect the a priori estimate used in the retrieval procedure, they are of little use for evaluating the effect of LBCs on ground concentrations. Rather, the evaluation of ground-level concentrations needs to rely on in situ ground observations. (iii) The improvements of dynamic over climatological LBCs become most apparent when using accumulated ozone over threshold 40 ppb (AOT40) as a metric. Also, when focusing on ground observations taken near the inflow boundary of the model domain, one finds that the use of dynamical LBCs yields a more accurate representation of the seasonal variation, as well as of the variability of the trace gas concentrations on shorter timescales.

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  • 16. Andersson, Emma
    et al.
    Kahnert, Michael
    SMHI, Research Department, Air quality.
    Coupling aerosol optics to the MATCH (v5.5.0) chemical transport model and the SALSA (v1) aerosol microphysics module2016In: Geoscientific Model Development, ISSN 1991-959X, E-ISSN 1991-9603, Vol. 9, no 5, p. 1803-1826Article in journal (Refereed)
    Abstract [en]

    A new aerosol-optics model is implemented in which realistic morphologies and mixing states are assumed, especially for black carbon particles. The model includes both external and internal mixing of all chemical species, it treats externally mixed black carbon as fractal aggregates, and it accounts for inhomogeneous internal mixing of black carbon by use of a novel "core-grey-shell" model. Simulated results of aerosol optical properties, such as aerosol optical depth, backscattering coefficients and the Angstrom exponent, as well as radiative fluxes are computed with the new optics model and compared with results from an older optics-model version that treats all particles as externally mixed homogeneous spheres. The results show that using a more detailed description of particle morphology and mixing state impacts the aerosol optical properties to a degree of the same order of magnitude as the effects of aerosol-microphysical processes. For instance, the aerosol optical depth computed for two cases in 2007 shows a relative difference between the two optics models that varies over the European region between 28 and 18 %, while the differences caused by the inclusion or omission of the aerosol-microphysical processes range from 50 to 37 %. This is an important finding, suggesting that a simple optics model coupled to a chemical transport model can introduce considerable errors affecting radiative fluxes in chemistry-climate models, compromising comparisons of model results with remote sensing observations of aerosols, and impeding the assimilation of satellite products for aerosols into chemical-transport models.

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  • 17. Andersson, Eva M.
    et al.
    Ogren, Mikael
    Molnar, Peter
    Segersson, David
    SMHI, Research Department, Air quality.
    Rosengren, Annika
    Stockfelt, Leo
    Road traffic noise, air pollution and cardiovascular events in a Swedish cohort2020In: Environmental Research, ISSN 0013-9351, E-ISSN 1096-0953, Vol. 185, article id 109446Article in journal (Refereed)
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  • 18.
    Andersson, Stefan
    et al.
    SMHI, Professional Services.
    Arvelius, Johan
    SMHI, Professional Services.
    Verbova, Marina
    SMHI, Professional Services.
    Omstedt, Gunnar
    SMHI, Research Department, Air quality.
    Torstensson, Martin
    SMHI, Professional Services.
    Identifiering av potentiella riskområden för höga halter av benso(a)pyren Nationell kartering av emissioner och halter av B(a)P från vedeldning i småhusområden2015Report (Other academic)
    Abstract [sv]

    Den här studien är en kartläggning och screening av emissioner och halter av benso(a)pyren (B(a)P) i Sverige. Syftet är att identifiera potentiella riskområden för överskridande av miljökvalitetsnormen (MKN). Ett övervägande bidrag till haltnivåerna till B(a)P är emissioner från den småskaliga vedeldningen, varför studien går ut på att beräkna och fördela emissionerna från uppvärmning av småhus. Metodiken består översiktligt av tre delar; beräkning av kommunvisa emissioner av B(a)P i Sverige, fördelning av dessa årsemissioner inom kommunerna på ett raster om 1 km × 1 km samt beräkning av årsmedelhalter utifrån detta emissionsraster. För att beräkna kommunvisa årsemissioner av B(a)P utnyttjas statistik från MSB över antalet eldstäder, modellerade värden på småhusens energibehov från ENLOSS, antaganden om eldvanor och emissionsfaktorer per typ av eldstad. De kommunvisa emissionerna fördelas sedan inom kommunen i ett grid om 1 km × 1 km utgående från antal kvadratmeter boyta småhus per km2 från fastighetsregistret. För pannor används dessutom tätortsvis statistik från Energimarknadsinspektionen över antal anslutna småhus till fjärrvärmenät, som vi enligt egen fördelning applicerar tätortsvis. Slutligen beräknas årsmedelhalter av B(a)P utifrån emissionsrastret på 1 km × 1 km utgående från linjära samband mellan emissioner och halter från tidigare genomförda lokalskaliga spridningsberäkningar med SIMAIR-ved i Västerbottenprojektet. Huvudslutsatserna från studien är följande: • De högsta årsemissionerna av B(a)P från vedpannor, som står för i särklass högst emission per enhet och därmed har störst påverkan på den lokala luftkvaliteten, beräknas för Skellefteå (18 200 g år–1) följt av Örnsköldsvik (13 600 g år–1), Gotland (13 500 g år–1), Sundsvall (12 900 g år–1) och Hudiksvall (12 300 g år–1). • Utifrån ett linjärt antagande mellan emissioner och halter fås kommunvisa årsmedelhalter av B(a)P 2012 på 0.03 – 1.03 ng m–3 för haltmåttet kartans högsta värde (KHV). Motsvarande värden för kartans ytmedelvärde (KYM) är 0.01 – 0.25 ng m–3. • Beräkningarna indikerar att det föreligger risk för överskridande av MKN (>1.0 ng m–3) i vissa enskilda gridrutor i tätorterna Sollefteå och Laholm (avseende årsmedelhalt av B(a)P uttryckt som KHV). Höga årsmedelhalter (>0.8 ng m–3) fås även för Kramfors, Säffle, Arvidsjaur, Boden, Skellefteå och Trollhättan. Detta är kommuner med en stor andel vedpannor i förhållande till lokaleldstäder. • Merparten (273 av 290) av kommunerna i Sverige har haltnivåer (KHV) högre än miljökvalitetsmålet Frisk luft (>0.1 ng m–3). Här är påverkan även betydande för utsläpp från trivseleldning med lokaleldstäder. • Studien ska ses som en översiktlig kartläggning och screening av emissioner och halter av B(a)P från småskaliga vedeldningen. Beräkningarna kan anses representera ett ”worst case”. • Den i särklass största osäkerheten vad gäller indata är statistiken från MSB över antalet eldstäder per kommun, samt hur eldstäderna fördelas mellan olika kommuner i gemensamma räddningstjänstområden. Detaljeringsgraden av underlaget samt klassificeringen av eldstäderna kan variera betydligt mellan olika kommuner/räddningstjänstförbund. För kommuner som enligt beräkningarna har haltnivåer som överskrider eller är nära att överskrida MKN rekommenderas, i ett första steg, att en noggrannare granskning/inventering görs av indata som används i beräkningarna, i synnerhet antalet eldstäder. In this report methods and results are presented from downscaling of about 40 climate

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  • 19.
    Andersson, Stefan
    et al.
    SMHI, Research Department, Air quality.
    Bergström, Robert
    SMHI, Research Department, Air quality.
    Omstedt, Gunnar
    SMHI, Research Department, Air quality.
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    Dagens och framtidens partikelhalter i Sverige: Utredning av exponeringsminskningsmål för PM2.5 enligt nytt luftdirektiv2008Report (Other academic)
    Abstract [sv]

    I det nya EU-direktivet för luftkvalitet definieras ett exponeringskoncentrationstak för PM2.5. Detta takvärde, som inte får överskridas efter år 2015, är satt till 20 μg/m3 som årsmedelvärde. Eftersom även lägre halter påverkar människors hälsa negativt införs även ett exponeringsminskningsmål av partikelhalter i urban bakgrund. Hur stort exponeringsminskningsmålet blir för en viss plats beror på PM2.5-halterna vid referensåret 2010. Högre halt kräver högre relativ reducering till år 2020. I denna studie utreds det nya direktivets betydelse för Sverige. Utgångsläget kartläggs genom analys av mätdata av PM2.5 för ett antal platser runt om i Sverige. Olika emissionsscenarier tillämpas för att undersöka hur den regionala PM2.5-halten och långdistansbidraget kan komma att ändras från nuläget till år 2020 genom simuleringar med spridningsmodellen MATCH. Då det gäller det lokala haltbidragets betydelse för totalhalten av PM2.5 i nuläget respektive för år 2020, undersöks detta genom beräkningar i SIMAIR, för olika emissionsscenarier som innefattar dubbdäcksanvändning, teknikutveckling och trafikökning. Mätdata har sammanställts och analyserats för 25 mätplatser, varav 4 regionala bakgrundsstationer, 8 urbana bakgrundsstationer samt 13 mätstationeri gaturum. Uppmätta årsmedelvärden av PM2.5 ligger i gaturum generellt i intervallet 10-18 μg/m3 medan motsvarande värden för urban bakgrundoch regional bakgrund är 9-12 μg/m3 respektive 6-12 μg/m3. Halterna av PM2.5 underskrider 20 μg/m3 för samtliga platser och år, vilket betyder attexponeringskoncentrationstaket redan i dagsläget är uppfyllt. Den relativa skillnaden mellan halter i gaturum och regional bakgrundsluft är betydligtmindre för PM2.5 än för PM10, vilket indikerar att merparten av de fina partiklarna i gaturum härstammar från långdistanskällor. Liksom för PM10observeras också för PM2.5 ett maximum på våren, vilket tyder på att en del av partiklarna från vägslitage och uppvirvling är fina. Långdistanstransporten från kontinentaleuropa leder till en nord-sydlig gradient av PM2.5 i regionala bakgrundsluften. Däremot kan inte någotentydigt latitudberoende observeras för gaturum.För att uppskatta möjliga reduceringar av årsmedelhalten av PM2.5 från år 2010 till år 2020 har modellsimuleringar utförts med den regionalaspridningsmodellen MATCH. Tre olika europeiska emissionsscenarier för 2020 har studerats (CLECLIM, D23LOW och MFRDEEP). Beräkningsresultaten ger reduceringar som uppgår till 1.0-2.5 μg/m3 i södra Sverige och 0.1-0.5 μg/m3 i norra Sverige, för ett troligt emissionsscenario (D23LOW). Utsikterna att uppnå målet 10% minskning av PM2.5-halterna i södra Sverige bedöms därför som goda. Beräkningarna visar också att långdistanstransporten är det dominerande bidraget till PM2.5 i regional bakgrundsluft i Sverige. Slutligen konstateras att för regionala bakgrundshalter av PM2.5 är påverkan från vägtrafikens slitagepartiklar liten. Bibehållen dubbdäcksanvänding år 2020 beräknas geen obetydlig ökning av fina slitagepartiklar i den regionala bakgrundsluften (maximalt ca 0.02 μg/m3) pga ökat trafikarbete, medan minskad användning av dubbdäck kan leda till en liten reducering av halterna till år 2020 (upp till ca 0.1 μg/m3 för scenariot utan dubbdäck). För halter i urbanbakgrundsluft förväntas påverkan vara något större än den som beräknats här.För att beräkna det lokala bidraget till PM2.5 har uppskattningar av totala emissionsfaktorer för PM2.5 gjorts. Uppskattningarna baserades på tidigarestudier med mätdata av hög kvalitet från gaturum i Sverige, Danmark och Tyskland samt modellberäkningar med hjälp av SIMAIRs emissionsmodellför slitagepartiklar. Utgående ifrån emissionsfaktorerna beräknades lokala haltbidrag i gaturummen med SIMAIR för 4 olika emissionsscenarier; (1)nuläge motsvarande år 2004, (2) år 2020 utan förändringar vad gäller dubbdäcksanvändning, (3) år 2020 andelar dubbdäck i hela landet är 30 % samt (4) år 2020 utan dubbdäck. Beräkningarna för dessa scenarier indikerar att under nuvarande förhållanden är det lokala haltbidraget av PM2.5 ca 6 μg/m3 i Stockholm/Hornsgatan, ca 4 μg/m3 i Umeå/Västra Esplanaden och ca 2.5-3 μg/m3 för Göteborg/Gårda och Malmö/Amiralsgatan.Teknikutveckling till år 2020 (scenario 2) minskar lokala haltbidrag med 1.3-2.3 μg/m3 och mindre dubbdäcksanvändning (scenario 3) reducerarhalterna med ytterligare 1-3 μg/m3 i främst Stockholm och Umeå. Däremot blir de beräknade halterna bara marginellt lägre i scenariot helt utandubbdäck jämfört med 30% dubbdäcksanvändning. Detta kan förklaras med att en gata, HC Andersens Boulevard i Köpenhamn, med högemissionsfaktor för uppvirvlingen av vägdamm, har använts som referensgata.

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  • 20.
    Andersson, Stefan
    et al.
    SMHI, Research Department, Air quality.
    Omstedt, Gunnar
    SMHI, Research Department, Air quality.
    Utvärdering av SIMAIR mot mätningar av PM10 och NO2 i Göteborg, Stockholm och Umeå för åren 2006-2009: Undersökning av en ny emissionsmodell för vägtrafikens slitagepartiklar2013Report (Other academic)
    Abstract [sv]

    SIMAIR är ett webbaserat modellsystem för beräkning av luftkvalitet i svenska tätorter. Systemet är utvecklat av SMHI på uppdrag av Trafikverket, Naturvårdsverket och Energimyndigheten och syftar till att tillhandahålla svenska kommuner och andra aktörer ett lättanvänt verktyg som kan användas i luftvårdsarbetet, bland annat för att bedöma luftföroreningsnivåerna i relation till miljökvalitetsnormer och utvärdera olika åtgärders effekter på luftmiljön. Syftet med denna studie är att utvärdera SIMAIR mot nya mätdata av PM10 och NO2 och testa och utvärdera en ny emissionsmodell för vägtrafikens slitagepartiklar.Högkvalitativa mätningar med timupplösning från tre trafikmiljöer har använts i utvärderingen; E6 vid Gårda i Göteborg för åren 2006-2009, Hornsgatan i Stockholm för åren 2007-2009 samt Västra Esplanaden i Umeå för åren 2006-2009. Modellens beräkningar i urban bakgrund (regionalt + urbant bidrag) har även utvärderats mot mätningar i urban bakgrund (i taknivå) för dessa tätorter; Femman-huset i Göteborg, Torkel Knutssonsgatan i Stockholm samt Biblioteket i Umeå. I utvärderingen används ett antal statistiska mått och indikatorer för att kvantifiera modellens prestanda i jämförelse med mätdata. Bland annat jämförs årsmedelvärden, percentiler, antalet överskridanden, bias, korrelationskoefficient och Target. I valideringen har ett nytt utvärderingsverktyg använts, Delta-tool, utvecklat inom ramen för det europeiska initiativet FAIRMODE.Utvärderingen av SIMAIR visar att i trafikmiljöer underskattas PM10-halterna något för Hornsgatan i Stockholm (med ca 20-30 %). För Västra Esplanden i Umeå och i synnerhet E6 vid Gårda i Göteborgöverskattas istället PM10-halterna (med 10-35 %). Däremot, i urban bakgrund är överensstämmelsen mellan modellerade och uppmätta PM10-halter genomgående mycket god.En systematisk underskattning av NO2-halterna kan observeras både i trafikmiljöer (generellt 10-30 %) och urban bakgrund (generellt 10-30 %) jämfört med mätdata (bortsett från urban bakgrund i Stockholmdär modellen uppvisar god överenstämmelse med mätdata). Trots att det finns ett viss bias för NO2 är resultaten ändå goda; 75 % av datapunkterna har ett lägre targetvärde än 1, vilket betyder att modellen då kan vara en bättre prediktor för atmosfärens ”verkliga” kemiska tillstånd än mätningarna.Denna studie tillsammans med tidigare valideringsstudie av SIMAIR visar att modellen uppfyller kvalitetsmålen på modellberäkningar (RPE/RDE) för såväl PM10 och NO2 i trafikmiljöer.Inom ramen för ett nordiskt forskningsprojekt har en ny emissionsmodell för vägdamm utvecklats; NORTRIP. Modellen bygger delvis på samma principer som SIMAIRs vägdammsmodell, men viktiga förbättringar har gjorts. Syftet med denna undersökning är att analysera förutsättningarna för att använda NORTRIP med hjälp av indata från SIMAIR. Undersökningen visar att det är möjligt, men att det finns en del svårigheter.NORTRIP-modellen ger något högre korrelation mot mätdata jämfört med SIMAIRs vägdammsmodell. Med övriga indata från SIMAIR för år 2007 ökar korrelationen från 0.58 till 0.67 för Västra Esplanaden,från 0.59 till 0.67 för Hornsgatan och från 0.53 till 0.57 för Gårda. För att få överensstämmande haltnivåer behövs dock korrektioner införas; korrektioner som för närvarande inte är lätta att förstå. Det är inte säkert att den standardparameteruppsättning, som tagits fram baserat på mätningar från två gator i Stockholm, är så generell att den också kan tillämpas för andra trafikmiljöer i Sverige.Ett enkelt sätt att förbättra SIMAIRs beräkningsresultat är att korrigera dessa mot mätdata. För att förbättra modellresultaten utan användandet av mätdata krävs förbättrade emissioner, vilket sannoliktkommer göras inom ramen för HBEFA i Europa, samt att implementera NORTRIP-modellen. Innan NORTRIP-modellen kan implementeras i SIMAIR behövs emellertid fler studier avseende vilka parametervärden och korrektioner som ska användas.

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  • 21.
    Andersson, Stefan
    et al.
    SMHI, Research Department, Air quality.
    Omstedt, Gunnar
    SMHI, Research Department, Air quality.
    Validering av SIMAIR mot mätningar av PM10, NO2 och bensen: Utvärdering för svenska tätorter och trafikmiljöer avseende år 2004 och 20052009Report (Other academic)
    Abstract [sv]

    I denna studie har SIMAIR (med SIMAIR avses i denna rapport SIMAIRväg) validerats mot mätningar av PM10, NO2 och bensen för 19 mätstationer i gaturum och 21 mätstationer i urban bakgrund. Trafikmiljöerna är av skiftande karaktär och från olika delar av Sverige. Mätstationerna i urban bakgrund är samtliga belägna vid en central plats i respektive tätort, men placeringen varierar (både mätningar vid torg och gågator samt takmätningar förekommer). Vid valideringen jämförs ett antal statistiska mått för att kvantifiera överensstämmelsen mellan uppmätta och beräknade halter. I EUs Luftdirektiv finns kvalitetsmått angivna, som fastställer maximalt acceptabel osäkerhet för modellberäkningar. Den bästa tolkningen av denna osäkerhet är begreppet RPEmax, det maximala relativa percentilfelet för 90% av stationerna, vilket är kvalitetsmåttet som tillämpas i denna studie. Utöver detta mått används även medianen för RPE (RPEmedian), vilket ur modelleringssynpunkt kanske är mer intressant. Andra statistiska mått som utvärderas är uppmätta och beräknade årsmedelvärden, percentiler för dygns- och timmedelvärden, variationskoefficient (CoV) och korrelationskoefficient (r). Där signalen är stark, det vill säga i trafikerade gaturum, är överensstämmelsen mellan uppmätta och beräknade halter god. För PM10 och NO2 klaras EUs kvalitetskrav med tämligen stor marginal, men för bensen överskattar dock SIMAIR halterna systematiskt ijämförelse med mätdata. För urban bakgrund är resultatet relativt bra för många stationer. EUs kvalitetskrav för PM10 klaras, men för NO2 underskattas halterna. Vad gäller bensen i urban bakgrund överskrids kvalitetskravet marginellt. Emellertid är resultaten bättre än för gaturum. Korrelationen är överlag tämligen stark för de flesta platser och SIMAIR återger representativ säsongsvariation av halterna.Att halterna av NO2 underskattas i den urbana bakgrunden kan delvis förklaras med att mätningar ofta representerar halter i punkter medan modellen representerar halter i kilometerrutor. Ur valideringssynpunkt är urbana mätstationer i taknivå lämpligast att göra jämförelser mot, då det finns viss risk att lokal haltpåverkan får genomslag i mätningar vid exempelvis öppna torg och gågator. En annan förklaring till att halterna i urban bakgrund underskattas är att SIMAIRs urbana modell, BUM, har brister i beskrivningen av stabila atmosfäriska förhållanden, vilket delvis kan förklara den stora underskattningen av halter av NO2 i norra Sverige. Parametriseringen vid stabila förhållanden behöver förbättras, vilket är ett arbete som har påbörjats. För tillfället används en statistisk metod för att korrigera detta, kallad klimatkorrigering, och denna metod visar sig förbättra modellberäkningarna för flertalet platser i Norrland. För Sandviken leder klimatkorrigering dock till att de beräknade halterna blir avsevärt högre än de uppmätta och här blir RPE större än innan. Den geografiska gränsen mellan var klimatkorrigering är lämplig och inte är således inte helt klar. För höga emissionsfaktorer för vägtrafikens utsläpp av bensen kan troligtvis förklara överskattningen som sker för beräkningarna i gaturum av bensenhalter. Denna del behöver granskas och uppdateras.

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  • 22.
    Andersson, Stefan
    et al.
    SMHI, Research Department, Air quality.
    Omstedt, Gunnar
    SMHI, Research Department, Air quality.
    Robertson, Lennart
    SMHI, Research Department, Air quality.
    Känslighetsanalys, vidareutveckling och validering av SIMAIRs urbana spridningsmodell BUM2010Report (Other academic)
    Abstract [en]

    The urban background dispersion model, BUM, used in the SIMAIR-system, is a simple trajectory model for evaluation of Air Quality in urban areas on 1 x 1 km spatial resolution. The urban contribution to concentrations in a receptor point is calculated from the emission sources in an upstream influence area whose size is dependent on the wind speed. This simple and attractive concept enables fast model calculations and the model is applied for more than 100 Swedish towns within SIMAIR. However, comparison with measured concentrations has shown that BUM underestimates levels of NO2 and NOX, especially for towns in northern Sweden. The reason for this is probably meteorological, i.e. it exemplifies the difficulties in describing the dispersion of air pollutants during strong stable atmospheric conditions. This problem has previously been solved by a statistical method (regression analysis), to adjust the calculations against measurements for towns in northern Sweden. The result of this method has varied widely; for some urban areas the result has been good while the correlation between measured and calculated concentrations has been lower for others. The aim of this study is, through a sensitivity analysis, to examine the parameters of the model that most significantly affect the levels of NO2, and subsequently improve the parametrization of these during stable atmospheric conditions. Furthermore, the results are validated against measurements from 13 urban areas in Sweden. According to the sensitivity analysis, it is the parametrization of the vertical dispersion parameter σz that most affects the levels of NO2. A new parametrization, which takes into account the stability, is introduced for urban areas outside major cities. This generally raises the concentrations with several μgm-3 on annual basis and 10’s μgm-3 for 98-percentile daily mean concentration. Furthermore, a correction of the meteorology (from Mesan) is introduced used in the calculations of BUM, for the meteorology to represent more urban (rough) conditions. The improvements of BUM lead to a better consistency between the model and the measurements. Generally, the correlation between the calculated and the measured concentrations of NO2 increases, and the time variation of concentrations is better captured in the model. Annual averages, and especially 98-percentile daily- and hourly mean value, are better reproduced in the improved version of BUM; when compared to measured concentrations, 37 % of data points are within ± 50 % for the original BUM while the corresponding results for the new BUM is 95 %. However, the new BUM model still doesn’t succeed, for all towns in northern Sweden, to fully reproduce the highest daily and hourly peaks of concentrations. In comparison with the original BUM climate corrected concentrations (in northern Sweden), the correlation between calculated and measured concentrations is higher for the new BUM, especially in terms of annual average, correlation coefficient and coefficient of variation.

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  • 23. Arnold, S. R.
    et al.
    Emmons, L. K.
    Monks, S. A.
    Law, K. S.
    Ridley, D. A.
    Turquety, S.
    Tilmes, S.
    Thomas, J. L.
    Bouarar, I.
    Flemming, J.
    Huijnen, V.
    Mao, J.
    Duncan, B. N.
    Steenrod, S.
    Yoshida, Y.
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Long, Y.
    Biomass burning influence on high-latitude tropospheric ozone and reactive nitrogen in summer 2008: a multi-model analysis based on POLMIP simulations2015In: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 15, no 11, p. 6047-6068Article in journal (Refereed)
    Abstract [en]

    We have evaluated tropospheric ozone enhancement in air dominated by biomass burning emissions at high latitudes (>50 degrees N) in July 2008, using 10 global chemical transport model simulations from the POLMIP multimodel comparison exercise. In model air masses dominated by fire emissions, Delta O-3/Delta CO values ranged between 0.039 and 0.196 ppbv ppbv(-1) (mean: 0.113 ppbv ppbv(-1)) in freshly fire-influenced air, and between 0.140 and 0.261 ppbv ppb(-1) (mean: 0.193 ppbv) in more aged fire-influenced air. These values are in broad agreement with the range of observational estimates from the literature. Model Delta PAN/Delta CO enhancement ratios show distinct groupings according to the meteorological data used to drive the models. ECMWF-forced models produce larger Delta PAN/Delta CO values (4.47 to 7.00 pptv ppbv(-1)) than GEOS5-forced models (1.87 to 3.28 pptv ppbv(-1)), which we show is likely linked to differences in efficiency of vertical transport during poleward export from mid-latitude source regions. Simulations of a large plume of biomass burning and anthropogenic emissions exported from towards the Arctic using a Lagrangian chemical transport model show that 4-day net ozone change in the plume is sensitive to differences in plume chemical composition and plume vertical position among the POLMIP models. In particular, Arctic ozone evolution in the plume is highly sensitive to initial concentrations of PAN, as well as oxygenated VOCs (acetone, acetaldehyde), due to their role in producing the peroxyacetyl radical PAN precursor. Vertical displacement is also important due to its effects on the stability of PAN, and subsequent effect on NOx abundance. In plumes where net ozone production is limited, we find that the lifetime of ozone in the plume is sensitive to hydrogen peroxide loading, due to the production of HOx from peroxide photolysis, and the key role of HO2 + O-3 in controlling ozone loss. Overall, our results suggest that emissions from biomass burning lead to large-scale photochemical enhancement in high-latitude tropospheric ozone during summer.

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  • 24.
    Asker, Christian
    et al.
    SMHI, Research Department, Air quality.
    Andersson, Camilla
    SMHI, Research Department, Air quality.
    Segersson, David
    SMHI, Research Department, Air quality.
    CLAIR-O3 - befolkningsexponering marknära ozon i Göteborg och Stockholm2021Report (Other academic)
    Abstract [sv]

    Vi har tagit fram en flexibel nedskalningsmetodik för marknära ozon, CLAIR-O3-metoden.Denna metodik nyttjar högupplösta utsläpp av kväveoxider för att skala ner modellberäknatozon på grövre upplösning. Detta har en vinst i form av ökad upplösning i närhet till utsläppav kväveoxider, t.ex. i urban miljö och närhet till stora vägar/industrier/bostadsområden.Metoden tillåter, utöver den ökade upplösningen, även en förbättring (korrigering) avregionalskaliga halter med regionalskaliga mätningar, såsom i MATCH sverigesystemet, mendet är inte nödvändigt utan nedskalningen av marknära ozon kan appliceras direkt påmodellerad bakgrundshalt. I denna studie har vi utgått från nationella bakgrundshalterframtaget med MATCH (5x5km2 upplösning), och korrigerat mot regionalabakgrundsmätningar på timskala.Vi har beräknat timhalter av marknära ozon för två svenska städer, Stockholm och Göteborg,för 2015 på 100x100m2 upplösning och använt dessa för att skatta befolkningsexponering istädernas kommuner. Högst exponering är generellt i Göteborg under 2015, med allra högstexponering i Kungälvs kommun. Högst exponering i Stockholm är i de ostliga kommunernaÖsteråker, Värmdö och Vaxholm medan den lägsta exponeringen är i Sundbyberg, Solna ochStockholms kommun.Våra modellresultat jämför sig väl mot i metoden oberoende mätdata, och mot enregressionsmetod som baseras på regression av mätningar. Denna metodik är tillämpbar överett större område, som hela Sverige, och längre tidsperioder, då den inte är beroende avtillgång till mätdata.Det finns fortsatta möjliga ytterligare metod och modellförbättringar. En förbättringsmöjlighetär förfinad hantering av hur regionalskalig halt först in i nedskalningsmodellen, vilket skullejämna ut det grövre rutmönstret i kartorna. En annan är att införa nedskalning medatmosfärisk stabilitet och höjd i landskapet vilket skulle möjliggöra beskrivning av högupplöstväxtexponering, vilket enbart hanteras i närhet till direkta utsläpp i denna metod.Metoden skulle kunna införas i miljöövervakningen med MATCH Sverigesystemet.

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    CLAIR-O3 - befolkningsexponering marknära ozon i Göteborg och Stockholm
  • 25. Astrom, Christofer
    et al.
    Astrom, Daniel Oudin
    Andersson, Camilla
    SMHI, Research Department, Air quality.
    Ebi, Kristie L.
    Forsberg, Bertil
    Vulnerability Reduction Needed to Maintain Current Burdens of Heat-Related Mortality in a Changing Climate-Magnitude and Determinants2017In: International Journal of Environmental Research and Public Health, ISSN 1661-7827, E-ISSN 1660-4601, Vol. 14, no 7, article id 741Article in journal (Refereed)
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  • 26. Astrom, Christofer
    et al.
    Ebi, Kristie L.
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Forsberg, Bertil
    Developing a Heatwave Early Warning System for Sweden: Evaluating Sensitivity of Different Epidemiological Modelling Approaches to Forecast Temperatures2015In: International Journal of Environmental Research and Public Health, ISSN 1661-7827, E-ISSN 1660-4601, Vol. 12, no 1, p. 254-267Article in journal (Refereed)
    Abstract [en]

    Over the last two decades a number of heatwaves have brought the need for heatwave early warning systems (HEWS) to the attention of many European governments. The HEWS in Europe are operating under the assumption that there is a high correlation between observed and forecasted temperatures. We investigated the sensitivity of different temperature mortality relationships when using forecast temperatures. We modelled mortality in Stockholm using observed temperatures and made predictions using forecast temperatures from the European Centre for Medium-range Weather Forecasts to assess the sensitivity. We found that the forecast will alter the expected future risk differently for different temperature mortality relationships. The more complex models seemed more sensitive to inaccurate forecasts. Despite the difference between models, there was a high agreement between models when identifying risk-days. We find that considerations of the accuracy in temperature forecasts should be part of the design of a HEWS. Currently operating HEWS do evaluate their predictive performance; this information should also be part of the evaluation of the epidemiological models that are the foundation in the HEWS. The most accurate description of the relationship between high temperature and mortality might not be the most suitable or practical when incorporated into a HEWS.

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    fulltext
  • 27. Astrom, Daniel Oudin
    et al.
    Adolfsson, Rolf
    Segersson, David
    SMHI, Research Department, Air quality.
    Forsberg, Bertil
    Oudin, Anna
    Local Contrasts in Concentration of Ambient Particulate Air Pollution (PM2.5) and Incidence of Alzheimer's Disease and Dementia: Results from the Betula Cohort in Northern Sweden Comment2021In: Journal of Alzheimer's Disease, ISSN 1387-2877, E-ISSN 1875-8908, Vol. 81, no 1, p. 83-85Article in journal (Refereed)
    Abstract [en]

    Exposure to fine particulate air pollution (PM2.5) is emerging as a risk factor for Alzheimer's disease (AD), but existing studies are still limited and heterogeneous. We have previously studied the association between dementia (AD and vascular dementia) and PM2.5 stemming from vehicle exhaust and wood-smoke in the Betula cohort in Northern Sweden. The aim of this commentary is to estimate the association between total PM2.5 and dementia in the Betula cohort, which is more relevant to include in future meta-estimates than the source-specific estimates. The hazard ratio for incident dementia associated with a 1 mu g/m(3) increase in local PM2.5 was 1.38 (95% confidence interval: 0.99 - 1.92). The interpretation of our results is that they indicate an association between local contrasts in concentration of PM2.5 at the residential address and incidence of dementia in a low-level setting.

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    Local Contrasts in Concentration of Ambient Particulate Air Pollution (PM2.5) and Incidence of Alzheimer’s Disease and Dementia: Results from the Betula Cohort in Northern Sweden
  • 28. Baldacchini, Chiara
    et al.
    Castanheiro, Ana
    Maghakyan, Nairuhi
    Sgrigna, Gregorio
    Verhelst, Jolien
    Alonso, Rocio
    Amorim, Jorge Humberto
    SMHI, Research Department, Air quality.
    Bellan, Patrick
    Bojovic, Danijela Dunisijevic
    Breuste, Juergen
    Buhler, Oliver
    Cantar, Ilie C.
    Carinanos, Paloma
    Carriero, Giulia
    Churkina, Galina
    Dinca, Lucian
    Esposito, Raffaela
    Gawronski, Stanislaw W.
    Kern, Maren
    Le Thiec, Didier
    Moretti, Marco
    Ningal, Tine
    Rantzoudi, Eleni C.
    Sinjur, Iztok
    Stojanova, Biljana
    Urosevic, Mira Anicic
    Velikova, Violeta
    Zivojinovic, Ivana
    Sahakyan, Lilit
    Calfapietra, Carlo
    Samson, Roeland
    How Does the Amount and Composition of PM Deposited on Platanus acerifolia Leaves Change Across Different Cities in Europe?2017In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 51, no 3, p. 1147-1156Article in journal (Refereed)
  • 29. Barre, Jerome
    et al.
    Petetin, Herve
    Colette, Augustin
    Guevara, Marc
    Peuch, Vincent-Henri
    Rouil, Laurence
    Engelen, Richard
    Inness, Antje
    Flemming, Johannes
    Garcia-Pando, Carlos Perez
    Bowdalo, Dene
    Meleux, Frederik
    Geels, Camilla
    Christensen, Jesper H.
    Gauss, Michael
    Benedictow, Anna
    Tsyro, Svetlana
    Friese, Elmar
    Struzewska, Joanna
    Kaminski, Jacek W.
    Douros, John
    Timmermans, Renske
    Robertson, Lennart
    SMHI, Research Department, Air quality.
    Adani, Mario
    Jorba, Oriol
    Joly, Mathieu
    Kouznetsov, Rostislav
    Estimating lockdown-induced European NO2 changes using satellite and surface observations and air quality models2021In: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 21, no 9, p. 7373-7394Article in journal (Refereed)
    Abstract [en]

    This study provides a comprehensive assessment of NO2 changes across the main European urban areas induced by COVID-19 lockdowns using satellite retrievals from the Tropospheric Monitoring Instrument (TROPOMI) onboard the Sentinel-5p satellite, surface site measurements, and simulations from the Copernicus Atmosphere Monitoring Service (CAMS) regional ensemble of air quality models. Some recent TROPOMI-based estimates of changes in atmospheric NO2 concentrations have neglected the influence of weather variability between the reference and lockdown periods. Here we provide weather-normalized estimates based on a machine learning method (gradient boosting) along with an assessment of the biases that can be expected from methods that omit the influence of weather. We also compare the weather-normalized satellite-estimated NO2 column changes with weather-normalized surface NO2 concentration changes and the CAMS regional ensemble, composed of 11 models, using recently published estimates of emission reductions induced by the lockdown. All estimates show similar NO2 reductions. Locations where the lockdown measures were stricter show stronger reductions, and, conversely, locations where softer measures were implemented show milder reductions in NO2 pollution levels. Average reduction estimates based on either satellite observations (-23 %), surface stations (-43 %), or models (-32 %) are presented, showing the importance of vertical sampling but also the horizontal representativeness. Surface station estimates are significantly changed when sampled to the TROPOMI overpasses (-37 %), pointing out the importance of the variability in time of such estimates. Observation-based machine learning estimates show a stronger temporal variability than model-based estimates.

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    Estimating lockdown-induced European NO2 changes using satellite and surface observations and air quality models
  • 30.
    Belusic, Danijel
    et al.
    SMHI, Research Department, Climate research - Rossby Centre.
    Berg, Peter
    SMHI, Research Department, Hydrology.
    Bozhinova, Denica
    SMHI, Research Department, Hydrology.
    Bärring, Lars
    SMHI, Research Department, Climate research - Rossby Centre.
    Doescher, Ralf
    SMHI, Research Department, Climate research - Rossby Centre.
    Eronn, Anna
    SMHI, Research Department, Climate research - Rossby Centre.
    Kjellström, Erik
    SMHI, Research Department, Climate research - Rossby Centre.
    Klehmet, Katharina
    SMHI, Research Department, Hydrology.
    Martins, Helena
    SMHI, Research Department, Climate research - Rossby Centre.
    Nilsson, Carin
    Olsson, Jonas
    SMHI, Research Department, Hydrology.
    Photiadou, Christiana
    SMHI, Research Department, Hydrology.
    Segersson, David
    SMHI, Research Department, Air quality.
    Strandberg, Gustav
    SMHI, Research Department, Climate research - Rossby Centre.
    Climate Extremes for Sweden2019Report (Other academic)
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  • 31.
    Bennet, Cecilia
    et al.
    SMHI, Research Department, Air quality.
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    A regional model for surface ozone in Southeast Asia2008In: Tellus. Series B, Chemical and physical meteorology, ISSN 0280-6509, E-ISSN 1600-0889, Vol. 60, no 5, p. 718-728Article in journal (Refereed)
    Abstract [en]

    As part of the model intercomparison study MICS Asia II, the Swedish MATCH model was set up for Southeast and East Asia. In that study, the comprehensive photochemistry scheme of MATCH was used for the first time in Asia. The current work focuses on results of surface ozone from the MATCH model simulations falling outside the model intercomparison study. Model results of surface ozone concentrations for the entire year of 2001 were investigated and compared with measurements in Southeast Asia. The model produced higher surface ozone concentrations than the observations at all of the non-remote stations investigated but underestimated during the dry season at remote locations. Modelled seasonal variation was similar to, but less pronounced than, the variation in the measurements. This study indicates that NO(x) is the limiting precursor for ozone production in the model, while the fractionation in different species and total amount of non-methane volatile organic compounds (NMVOC) emissions are less important. Naturally emitted NMVOC, isoprene, is an important precursor of surface ozone at certain conditions, and a better inventory of these emissions is needed. Deposition velocities of ozone also have impact on surface concentrations. To improve the model performance, it is important to add a land use inventory with corresponding deposition velocities.

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  • 32.
    Bennet, Cecilia
    et al.
    SMHI, Research Department, Air quality.
    Jonsson, P
    Lindgren, E S
    Concentrations and sources of trace elements in particulate air pollution, Dar es Salaam, Tanzania, studied by EDXRF2005In: X-Ray Spectrometry, ISSN 0049-8246, E-ISSN 1097-4539, Vol. 34, no 1, p. 1-6Article in journal (Refereed)
    Abstract [en]

    Trace elements in near-ground atmospheric aerosols were investigated in Dar es Salaam, Tanzania. Particles were collected at two sites, one urban and one rural, during, two months with different meteorological conditions. The samplers, dichotomous impactors, segregate the particles into two size fractions, fine (PM2.5, d(a) < 2.5 mum) and coarse (2.5 < d(a) < 10 mum). A sharp cyclone was used to sample finer particles (PM1, d(a) < 1 mum). Meteorological parameters were also examined at both sites. An EDXRF spectrometer, based on three-axial geometry, was used for quantitative elemental analysis. Concentrations of elements heavier than phosphorus were determined. Also, the content of black carbon on the filters was measured with a reflectometer. The elemental concentrations were compared with respect to season and geographical location in the city. The levels of different species in Dar es Salaam were also compared with similar data from other African and European countries. This showed low values of Pb with respect to the size of the city and no legislation on the use of leaded petrol, that often is the main source of lead. High values of Cl were also found, as would be expected in a coastal city. The coarse particles in the air, originating from soil, had a different composition in Dar es Salaam than in Gaborone, Botswana, and the concentration of black carbon was higher than in other cities. On the basis of the data collected, source assignments were made and the following sources found; sea-spray, soil, city road dust, biomass burning industries and traffic. Comparing the concentrations of different elements in PM2.5 and PM1 revealed that black carbon, Zn, Pb, K and Br are present only in the smallest particles. Copyright (C) 2005 John Wiley Sons, Ltd.

  • 33.
    Bergström, Robert
    SMHI, Research Department, Air quality.
    How should condensables be included in PM emission inventories reported to EMEP/CLRTAP?2020In: EMEP, ISSN 1504-6206, no 4, p. 1-72Article in journal (Other academic)
    Abstract [en]

    Condensable primary organic aerosol emissions are a class of organic compounds that arevapour phase at stack conditions, but which undergo both condensation and evaporation processes as the stack air is cooled and diluted upon discharge into ambient air. Emission factorsmeasured in or close to the high-temperature high-concentration exhaust stack or pipe maymisrepresent, and even miss, the amount of PM or gas that actually enters the atmosphere,depending on the filters, dilution and sampling conditions of the emission measurement. Inthe current emission reporting to EMEP/CLRTAP there is no clear definition of whether condensable organics are included or not, and, if included, to what extent.

    In March 2020 MSC-W hosted an expert workshop on condensable organic aerosol emissions (funded by the Nordic Council of Ministers), which brought together experts in emissions, measurements, emission inventories, atmospheric chemistry, air quality models andpolicy from Europe and North America, and to create a much better understanding of theissues and possible approaches for dealing with this important class of compounds.

    More than 30 experts took part in the (zoom) meeting, including EMEP Chairs (EMEPSteering Body, TFIAM, TFMM, TFEIP, TFTEI), EMEP Centres (MSC-W, CEIP, CIAM),inventory developers (TNO, CIAM, COPERT, and national experts from UBA - Germany,SINTEF - Norway, IVL, ACES, Swedish EPA - Sweden, CITEPA, INERIS - France, ECCC- Canada, Univ. Patras - Greece), measurement experts (PSI - Switzerland, INERIS - France,Univ. York - England, NC State University - USA), industry (Concawe), the US EPA and theEuropean Commission. The workshop discussed a number of approaches for dealing with thisimportant class of compounds. This executive summary presents some of the key messagesfrom the workshop. Further background, addressing the technical matters in more detail canbe found in the main body of the report.

    The main idea of the workshop was to promote discussion among different communitiesand Task Forces that have different expertise and needs with regard to condensable organics and PM emission inventories. In order to aid these discussions, a number of importantquestions were identified:

    1. For which source categories are condensable organics important?

    2. What is included in official national and other emission inventories?

    3. Do we expect emissions of condensable organics to be missing in these inventories?

    4. Can we reliably predict the contribution of condensable vapours from major sources toambient PM using data from a smaller number of representative cases?

    5. Can we recommend a practical approach for inclusion (or exclusion) of condensables in (a) emission inventories, and (b) chemical transport models?

    One of the ongoing major tasks for the Air Convention (CLRTAP) is the revision of the socalled ‘Gothenburg’ Protocol 1, with a final report of the review to be completed during 2022.It is important to note that for this review process, the consideration of condensables facesseveral (competing) challenges:

    (a) The need for emission data as soon as possible that are consistent across countries inorder to get a fair ‘optimised’ distribution of emission abatement efforts aimed at improving health and ecosystems protection targets;

    (b) The difficulties to change existing practices of some countries;

    (c) The wish of scientists to start multi-year work programs for the best possible way todefine and quantify condensable emissions and/or secondary PM formation in the atmosphere.

    (d) The need to assess the available options for short and longer term actions in terms ofe.g. time frame (feas

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    How should condensables be included in PM emission inventories reported to EMEP/CLRTAP?
  • 34.
    Bergström, Robert
    SMHI, Research Department, Air quality.
    TESS - Traffic Emissions, Socioeconomic valuation and Socioeconomic measures: Part 2: Exposure of the European population to atmospheric particles (PM) caused by emissions in Stockholm2008Report (Other academic)
    Abstract [en]

    Model calculations have been performed to estimate the effects of emissions in Stockholm on the population exposure to particulate matter (PM) outside the city.The impacts of five different emissions were investigated: Road traffic exhaust, split into Light Duty Vehicles (LDV) and Heavy Duty Vehicles(HDV), Sea Traffic, Power Plants and Residential Heating. The emissions from non-exhaust (mainly road wear due to use of studded tyres) were also treated, in addition to combustion sources.The uncertainties in the emission estimates for Residential Heating using biomass (wood) are very large but it seems that it is an important PM source in Stockholm. In this report two estimates of the emissions have been used. In the lowest estimate, which seems more realistic, the contribution to population exposure of directly emitted combustion particles from residential heating is of similar magnitude (37%) as the contribution from road traffic exaust (42%). For all sources, except Sea Traffic, the total population exposure to combustion PM is much larger within Stockholm than outside; for shipping the total exposure is about as large outside the city as within.For all sources, except residential heating, the secondary inorganic aerosol (SIA) exposure is higher than the combustion particle exposure. Non-exhaust particles dominate the total impact on PM10 exposure, contributing about 60-70% to the total exposure, due to all the studied sources in Stockholm. The calculated population exposure due to the wear particles is to a very large extent (87%) occurring within the Greater Stockholm area.

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  • 35.
    Bergström, Robert
    SMHI, Research Department, Air quality.
    Transboundary particulate matter, photo-oxidants, acidifying and eutrophying components2020In: EMEP, ISSN 1504-6192, no 1, p. 1-270Article in journal (Other academic)
    Abstract [en]

    This report presents the EMEP activities in 2019 and 2020 in relation to transboundary fluxesof particulate matter, photo-oxidants, acidifying and eutrophying components, with focus onresults for 2018. It presents major results of the activities related to emission inventories,observations and modelling. The report also introduces specific relevant research activitiesaddressing EMEP key challenges, as well as technical developments of the observation andmodelling capacities.

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    Transboundary particulate matter, photo-oxidants, acidifying and eutrophying components
  • 36.
    Bergström, Robert
    et al.
    SMHI, Research Department, Air quality.
    Hallquist, M.
    Simpson, D.
    Wildt, J.
    Mentel, T. F.
    Biotic stress: a significant contributor to organic aerosol in Europe?2014In: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 14, no 24, p. 13643-13660Article in journal (Refereed)
    Abstract [en]

    We have investigated the potential impact on organic aerosol formation from biotic stress-induced emissions (SIE) of organic molecules from forests in Europe (north of lat. 45 degrees N). Emission estimates for sesquiterpenes (SQT), methyl salicylate (MeSA) and unsaturated C-17 compounds, due to different stressors, are based on experiments in the Julich Plant Atmosphere Chamber (JPAC), combined with estimates of the fraction of stressed trees in Europe based on reported observed tree damage. SIE were introduced in the EMEP MSC-W chemical transport model and secondary organic aerosol (SOA) yields from the SIE were taken from the JPAC experiments. Based on estimates of current levels of infestation and the JPAC aerosol yields, the model results suggest that the contribution to SOA in large parts of Europe may be substantial. It is possible that SIE contributes as much, or more, to organic aerosol than the constitutive biogenic VOC emissions, at least during some periods. Based on the assumptions in this study, SIE-SOA are estimated to constitute between 50 and 70% of the total biogenic SOA (BSOA) in a current-situation scenario where the biotic stress in northern and central European forests causes large SIE of MeSA and SQT. An alternative current-situation scenario with lower SIE, consisting solely of SQT, leads to lower SIE-SOA, between 20 and 40% of the total BSOA. Hypothetical future scenarios with increased SIE, due to higher degrees of biotic stress, show that SOA formation due to SIE can become even larger. Unsaturated C17 BVOC (biogenic volatile organic compounds) emitted by spruce infested by the forest-honey generating bark louse, Cinara pilicornis, have a high SOA-forming potential. A model scenario investigating the effect of a regional, episodic infestation of Cinara pilicornis in Baden-Wurttemberg, corresponding to a year with high production of forest honey, shows that these types of events could lead to very large organic aerosol formation in the infested region. We have used the best available laboratory data on biotic SIE applicable to northern and central European forests. Using these data and associated assumptions, we have shown that SIE are potentially important for SOA formation but the magnitude of the impact is uncertain and needs to be constrained by further laboratory, field and modelling studies. As an example, the MeSA, which is released as a consequence of various types of biotic stress, is found to have a potentially large impact on SIE-SOA in Europe, but different assumptions regarding the nighttime chemistry of MeSA can change its SOA potential substantially. Thus, further investigations of the atmospheric chemistry of MeSA and observational field studies are needed to clarify the role of this compound in the atmosphere.

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  • 37.
    Bergström, Robert
    et al.
    SMHI, Research Department, Air quality.
    van der Gon, H. A. C. Denier
    Prevot, A. S. H.
    Yttri, K. E.
    Simpson, D.
    Modelling of organic aerosols over Europe (2002-2007) using a volatility basis set (VBS) framework: application of different assumptions regarding the formation of secondary organic aerosol2012In: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 12, no 18, p. 8499-8527Article in journal (Refereed)
    Abstract [en]

    A new organic aerosol module has been implemented into the EMEP chemical transport model. Four different volatility basis set (VBS) schemes have been tested in long-term simulations for Europe, covering the six years 2002-2007. Different assumptions regarding partitioning of primary organic aerosol and aging of primary semi-volatile and intermediate volatility organic carbon (S/IVOC) species and secondary organic aerosol (SOA) have been explored. Model results are compared to filter measurements, aerosol mass spectrometry (AMS) data and source apportionment studies, as well as to other model studies. The present study indicates that many different sources contribute significantly to organic aerosol in Europe. Biogenic and anthropogenic SOA, residential wood combustion and vegetation fire emissions may all contribute more than 10% each over substantial parts of Europe. This study shows smaller contributions from biogenic SOA to organic aerosol in Europe than earlier work, but relatively greater anthropogenic SOA. Simple VBS based organic aerosol models can give reasonably good results for summer conditions but more observational studies are needed to constrain the VBS parameterisations and to help improve emission inventories. The volatility distribution of primary emissions is one important issue for further work. Emissions of volatile organic compounds from biogenic sources are also highly uncertain and need further validation. We can not reproduce winter levels of organic aerosol in Europe, and there are many indications that the present emission inventories substantially underestimate emissions from residential wood combustion in large parts of Europe.

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  • 38. Borrego, C.
    et al.
    Amorim, Jorge Humberto
    SMHI, Research Department, Air quality.
    Tchepel, O.
    Dias, D.
    Rafael, S.
    Sa, E.
    Pimentel, C.
    Fontes, T.
    Fernandes, P.
    Pereira, S. R.
    Bandeira, J. M.
    Coelho, M. C.
    Urban scale air quality modelling using detailed traffic emissions estimates2016In: Atmospheric Environment, ISSN 1352-2310, E-ISSN 1873-2844, Vol. 131, p. 341-351Article in journal (Refereed)
    Abstract [en]

    The atmospheric dispersion of NOx and PM10 was simulated with a second generation Gaussian model over a medium-size south-European city. Microscopic traffic models calibrated with GPS data were used to derive typical driving cycles for each road link, while instantaneous emissions were estimated applying a combined Vehicle Specific Power/Co-operative Programme for Monitoring and Evaluation of the Long-range Transmission of Air Pollutants in Europe (VSP/EMEP) methodology. Site-specific background concentrations were estimated using time series analysis and a low-pass filter applied to local observations. Air quality modelling results are compared against measurements at two locations for a 1 week period. 78% of the results are within a factor of two of the observations for 1-h average concentrations, increasing to 94% for daily averages. Correlation significantly improves when background is added, with an average of 0.89 for the 24 h record. The results highlight the potential of detailed traffic and instantaneous exhaust emissions estimates, together with filtered urban background, to provide accurate input data to Gaussian models applied at the urban scale. (C) 2016 Elsevier Ltd. All rights reserved.

  • 39. Brenot, Hugues
    et al.
    Theys, Nicolas
    Clarisse, Lieven
    van Gent, Jeroen
    Hurtmans, Daniel R.
    Vandenbussche, Sophie
    Papagiannopoulos, Nikolaos
    Mona, Lucia
    Virtanen, Timo
    Uppstu, Andreas
    Sofiev, Mikhail
    Bugliaro, Luca
    Vazquez-Navarro, Margarita
    Hedelt, Pascal
    Parks, Michelle Maree
    Barsotti, Sara
    Coltelli, Mauro
    Moreland, William
    Scollo, Simona
    Salerno, Giuseppe
    Arnold-Arias, Delia
    Hirtl, Marcus
    Peltonen, Tuomas
    Lahtinen, Juhani
    Sievers, Klaus
    Lipok, Florian
    Rufenacht, Rolf
    Haefele, Alexander
    Hervo, Maxime
    Wagenaar, Saskia
    de Cerff, Wim Som
    de Laat, Jos
    Apituley, Arnoud
    Stammes, Piet
    Laffineur, Quentin
    Delcloo, Andy
    Robertson, Lennart
    SMHI, Research Department, Air quality.
    Rokitansky, Carl-Herbert
    Vargas, Arturo
    Kerschbaum, Markus
    Resch, Christian
    Zopp, Raimund
    Plu, Matthieu
    Peuch, Vincent-Henri
    Van Roozendael, Michel
    Wotawa, Gerhard
    EUNADICS-AV early warning system dedicated to supporting aviation in the case of a crisis from natural airborne hazards and radionuclide clouds2021In: Natural hazards and earth system sciences, ISSN 1561-8633, E-ISSN 1684-9981, Vol. 21, no 11, p. 3367-3405Article in journal (Refereed)
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    EUNADICS-AV early warning system dedicated to supporting aviation in the case of a crisis from natural airborne hazards and radionuclide clouds
  • 40.
    Bringfelt, Björn
    et al.
    SMHI.
    Backström, Hans
    SMHI, Professional Services.
    Kindell, Sven
    SMHI, Professional Services.
    Omstedt, Gunnar
    SMHI, Research Department, Air quality.
    Persson, Christer
    SMHI, Research Department, Air quality.
    Ullerstig, Anders
    SMHI, Research Department, Climate research - Rossby Centre.
    Calculations of PM-10 concentrations in Swedish cities - Modelling of inhalable particles1997Report (Other academic)
    Abstract [en]

    The project was initiated by the Swedish Environmental Protection Agency in order to improve the basis for making standards for PM-10 concentrations in urban air. Model development has been made for Norrköping and Gothenburg. Modelling has been necessary of both long-range and local contributions.

    The long-range dispersion has been simulated by the MATCH-Europe and MATCH-Sweden models, the former being a conventional dispersion model based on meteorology and emission data and the latter including also results from background air pollution measurements in Sweden and neighbouring countries.

    For the local scale, both car exhaust panicles and resuspended particles from a traffic source inventory are dispersed in the city using meteorological data and a Gaussian dispersion mode! and, if needed, a street canyon dispersion submodel. For panicle resuspension, a new model has been developed. The parameters of the resuspension model have been adjusted to two streets/measuring periods in Norrköping.

    At street level in Norrköping, the local model showed to contribute to a large part of the total concentration, especially in late winter and early spring due to resuspension. The MATCH mode! gives same underestimate due to the absence of organic compounds and simulation of PM-2.5 instead of PM-10. However, at some episodes in Norrköping and, in general, for a station at roof level in central Gothenburg and at the rural station Aspvreten, the model estimates of regional PM-2.5 concentrations constitute a larger part of the observed PM-10 concentrations. A good covariation in time with measured data occurs for both the MATCH model and the local model.

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  • 41. Burton, S. P.
    et al.
    Hair, J. W.
    Kahnert, Michael
    SMHI, Research Department, Air quality.
    Ferrare, R. A.
    Hostetler, C. A.
    Cook, A. L.
    Harper, D. B.
    Berkoff, T. A.
    Seaman, S. T.
    Collins, J. E.
    Fenn, M. A.
    Rogers, R. R.
    Observations of the spectral dependence of linear particle depolarization ratio of aerosols using NASA Langley airborne High Spectral Resolution Lidar2015In: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 15, no 23, p. 13453-13473Article in journal (Refereed)
    Abstract [en]

    Linear particle depolarization ratio is presented for three case studies from the NASA Langley airborne High Spectral Resolution Lidar-2 (HSRL-2). Particle depolarization ratio from lidar is an indicator of non-spherical particles and is sensitive to the fraction of non-spherical particles and their size. The HSRL-2 instrument measures depolarization at three wavelengths: 355, 532, and 1064 nm. The three measurement cases presented here include two cases of dust-dominated aerosol and one case of smoke aerosol. These cases have partial analogs in earlier HSRL-1 depolarization measurements at 532 and 1064 nm and in literature, but the availability of three wavelengths gives additional insight into different scenarios for non-spherical particles in the atmosphere. A case of transported Saharan dust has a spectral dependence with a peak of 0.30 at 532 nm with smaller particle depolarization ratios of 0.27 and 0.25 at 1064 and 355 nm, respectively. A case of aerosol containing locally generated wind-blown North American dust has a maximum of 0.38 at 1064 nm, decreasing to 0.37 and 0.24 at 532 and 355 nm, respectively. The cause of the maximum at 1064 nm is inferred to be very large particles that have not settled out of the dust layer. The smoke layer has the opposite spectral dependence, with the peak of 0.24 at 355 nm, decreasing to 0.09 and 0.02 at 532 and 1064 nm, respectively. The depolarization in the smoke case may be explained by the presence of coated soot aggregates. We note that in these specific case studies, the linear particle depolarization ratio for smoke and dust-dominated aerosol are more similar at 355 nm than at 532 nm, having possible implications for using the particle depolarization ratio at a single wavelength for aerosol typing.

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  • 42. Cardoso Pereira, Susana
    et al.
    Marta-Almeida, Martinho
    Carvalho, Ana
    SMHI, Research Department, Air quality.
    Heat wave and cold spell changes in Iberia for a future climate scenario2017In: International Journal of Climatology, ISSN 0899-8418, E-ISSN 1097-0088Article, review/survey (Refereed)
    Abstract [en]

    : This study investigates the impacts of climate change scenario on summer heat waves’ (HWs) and winter cold spells’ (CSs) characteristics for 12 locations over the Iberian Peninsula (IP). These characteristics are duration, recovery factor and intensity. Two future time slices of the chosen scenario are studied, namely, the periods 2046–2065 and 2081–2100 which are compared with a reference climate for the recent-past (1986–2005). The RCP8.5 greenhouse gas emission scenario is considered. The minimum and maximum daily temperature were obtained for these periods through regional model simulations using the Weather and Research Forecast (WRF) model forced with the MPI-ESM-LR model. The model was validated against EOBS and SPAIN02 datasets. The model shows 90th/10th percentile temperature (i.e. thresholds to identify HW/CS) biases. Therefore, HW/CS numbers and properties were evaluated using the model’s respective thresholds. HW/CS numbers and characteristics were also compared between the model and EOBS derived data. Probability density functions (PDFs) of the duration, recovery factor and intensity show significant changes in the mean and variance for the summer HWs. Differences, between future and recent-past climate in the extremes are evaluated by the 95th percentile which show an increase in the duration and intensity of the HWs for the future time slices. Very few CSs were detectable in the mid-term future (2046–2065) and none in the long-term future (2080–2100), except for Barcelona. For most locations, the CS for the future are of smaller duration and intensity. The PDF of the recovery factor suggests smaller absolute differences between the minimum and maximum temperature during winter which is also confirmed by the percentile analysis. The increase in the duration and intensity of HWs is greater in the long-term future than in the mid-term future, pointing for a warmer IP with more and longer HWs towards the end of the XXI century

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  • 43. Carlsen, Hanne Krage
    et al.
    Back, Erik
    Eneroth, Kristina
    Gislason, Thorarinn
    Holm, Mathias
    Janson, Christer
    Jensen, Steen Solvang
    Johannessen, Ane
    Kaasik, Marko
    Modig, Lars
    Segersson, David
    SMHI, Research Department, Air quality.
    Sigsgaard, Torben
    Forsberg, Bertil
    Olsson, David
    Orru, Hans
    Indicators of residential traffic exposure: Modelled NOX, traffic proximity, and self-reported exposure in RHINE III2017In: Atmospheric Environment, ISSN 1352-2310, E-ISSN 1873-2844, Vol. 167, p. 416-425Article in journal (Refereed)
  • 44. Carlsen, Hanne Krage
    et al.
    Nyberg, Fredrik
    Toren, Kjell
    Segersson, David
    SMHI, Research Department, Air quality.
    Olin, Anna-Carin
    Exposure to traffic-related particle matter and effects on lung function and potential interactions in a cross-sectional analysis of a cohort study in west Sweden2020In: BMJ Open, E-ISSN 2044-6055, Vol. 10, no 10, article id e034136Article in journal (Refereed)
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  • 45. Carmichael, G R
    et al.
    Calori, G
    Hayami, H
    Uno, I
    Cho, S Y
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    Kim, S B
    Ichikawa, Y
    Ikeda, Y
    Woo, J H
    Ueda, H
    Amann, M
    The MICS-Asia study: model intercomparison of long-range transport and sulfur deposition in East Asia2002In: Atmospheric Environment, ISSN 1352-2310, E-ISSN 1873-2844, Vol. 36, no 2, p. 175-199Article in journal (Refereed)
    Abstract [en]

    An intercomparison study involving eight long-range transport models for sulfur deposition in East Asia has been initiated, The participating models included Eulerian and Lagrangian frameworks, with a wide variety of vertical resolutions and numerical approaches. Results from this study, in which models used common data sets for emissions, meteorology, and dry, wet and chemical conversion rates, are reported and discussed. Model results for sulfur dioxide and sulfate concentrations, wet deposition amounts, for the period January and May 1993, are compared with observed quantities at 18 surface sites in East Asia. At many sites the ensemble of models is found to have high skill in predicting observed quantities. At other sites all models show poor predictive capabilities. Source-receptor relationships estimated by the models are also compared. The models show a high degree of consistency in identifying the main source-receptor relationships, as well as in the relative contributions of wet/dry pathways for removal. But at some locations estimated deposition amounts can vary by a factor or 5. The influence of model structure and parameters on model performance is discussed. The main factors determining the deposition fields are the emissions and underlying meteorological fields. Model structure in terms of vertical resolution is found to be more important than the parameterizations used for chemical conversion and removal, as these processes are highly coupled and often work in compensating directions. (C) 2002 Elsevier Science Ltd. All rights reserved.

  • 46. Carmichael, G R
    et al.
    Hayami, H
    Calori, G
    Uno, I
    Cho, S Y
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    Kim, S B
    Ichikawa, Y
    Ikeda, Y
    Ueda, H
    Amann, M
    Model intercomparison study of long range transport and sulfur deposition in East Asia (MICS-ASIA)2001In: Water, Air and Soil Pollution, ISSN 0049-6979, E-ISSN 1573-2932, Vol. 130, no 1-4, p. 51-62Article in journal (Refereed)
    Abstract [en]

    To help improve the use of models in science & policy analysis in Asia it is necessary to have a better understanding of model performance and uncertainties. Towards this goal an intercomparison exercise has been initiated as a collaborative study of scientists interested in long-range transport in East Asia. An overview of this study is presented in this paper. The study consists of a set of prescribed test calculations with carefully controlled experiments. Models used the same domain, emission inventory, model parameters, meteorological conditions, etc. Two periods (January and May 1993) were selected to reflect long-range transport conditions under two distinct seasons. During these periods measurements of sulfur concentrations and deposition were made throughout the study region using identical sampling and analysis protocols. The intercomparison activity consists of four tasks (Blind Test, Fixed Parameter Test, Source Receptor test, and Tuning Test). All participants were asked to do Task A, and as many of the other tasks as possible. To date seven different models have participated in this study. Results and key findings are presented.

  • 47. Carmichael, G. R.
    et al.
    Sakurai, T.
    Streets, D.
    Hozumi, Y.
    Ueda, H.
    Park, S. U.
    Fung, C.
    Han, Z.
    Kajino, M.
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    Bennet, Cecilia
    SMHI, Research Department, Air quality.
    Hayami, H.
    Sartelet, K.
    Holloway, T.
    Wang, Z.
    Kannari, A.
    Fu, J.
    Matsuda, K.
    Thongbooncho, N.
    Amann, M.
    MICS-Asia II: The model intercomparison study for Asia Phase II methodology and overview of findings2008In: Atmospheric Environment, ISSN 1352-2310, E-ISSN 1873-2844, Vol. 42, no 15, p. 3468-3490Article, review/survey (Refereed)
    Abstract [en]

    Results from the Model Intercomparison Study Asia Phase II (MICS-Asia II) are presented. Nine different regional modeling groups simulated chemistry and transport of ozone (O-3), secondary aerosol, acid deposition, and associated precursors, using common emissions and boundary conditions derived from a global model. Four-month-long periods, representing 2 years and three seasons (i.e., March, July, and December in 2001, and March in 2002), are analyzed. New observational data, obtained under the EANET (the Acid Deposition Monitoring Network in East Asia) monitoring program, were made available for this study, and these data provide a regional database to compare with model simulations. The analysis focused around seven subject areas: O-3 and related precursors, aerosols, acid deposition, global inflow of pollutants and precursor to Asia, model sensitivities to aerosol parameterization, analysis of emission fields, and detailed analyses of individual models, each of which is presented in a companion paper in this issue of Atmospheric Environment. This overview discusses the major findings of the study, as well as information on common emissions, meteorological conditions, and observations. (C) 2007 Elsevier Ltd. All rights reserved.

  • 48. Ciarelli, Giancarlo
    et al.
    Colette, Augustin
    Schucht, Simone
    Beekmann, Matthias
    Andersson, Camilla
    SMHI, Research Department, Air quality.
    Manders-Groot, Astrid
    Mircea, Mihaela
    Tsyro, Svetlana
    Fagerli, Hilde
    Ortiz, Alberto Gonzalez
    Adani, Mario
    Briganti, Gino
    Cappelletti, Andrea
    D'Isidoro, Massimo
    Cuvelier, Cornelis
    Couvidat, Florian
    Meleux, Frederik
    Bessagnet, Bertrand
    Long-term health impact assessment of total PM2.5 in Europe during the 1990-2015 period2019In: ATMOSPHERIC ENVIRONMENT-X, ISSN 2590-1621, Vol. 3, article id UNSP 100032Article in journal (Refereed)
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  • 49. Ciarelli, Giancarlo
    et al.
    Theobald, Mark R.
    Vivanco, Marta G.
    Beekmann, Matthias
    Aas, Wenche
    Andersson, Camilla
    SMHI, Research Department, Air quality.
    Bergström, Robert
    SMHI, Research Department, Air quality.
    Manders-Groot, Astrid
    Couvidat, Florian
    Mircea, Mihaela
    Tsyro, Svetlana
    Fagerli, Hilde
    Mar, Kathleen
    Raffort, Valentin
    Roustan, Yelva
    Pay, Maria-Teresa
    Schaap, Martijn
    Kranenburg, Richard
    Adani, Mario
    Briganti, Gino
    Cappelletti, Andrea
    D'Isidoro, Massimo
    Cuvelier, Cornelis
    Cholakian, Arineh
    Bessagnet, Bertrand
    Wind, Peter
    Colette, Augustin
    Trends of inorganic and organic aerosols and precursor gases in Europe: insights from the EURODELTA multi-model experiment over the 1990-2010 period2019In: Geoscientific Model Development, ISSN 1991-959X, E-ISSN 1991-9603, Vol. 12, no 12, p. 4923-4954Article in journal (Refereed)
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  • 50. Colette, Augustin
    et al.
    Andersson, Camilla
    SMHI, Research Department, Air quality.
    Baklanov, Alexander
    Bessagnet, Bertrand
    Brandt, Jorgen
    Christensen, Jesper H.
    Doherty, Ruth
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    Geels, Camilla
    Giannakopoulos, Christos
    Hedegaard, Gitte B.
    Katragkou, Eleni
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Lei, Hang
    Manders, Astrid
    Melas, Dimitris
    Meleux, Frederik
    Rouil, Laurence
    Sofiev, Mikhail
    Soares, Joana
    Stevenson, David S.
    Tombrou-Tzella, Maria
    Varotsos, Konstantinos V.
    Young, Paul
    Is the ozone climate penalty robust in Europe?2015In: Environmental Research Letters, E-ISSN 1748-9326, Vol. 10, no 8, article id 084015Article in journal (Refereed)
    Abstract [en]

    Ozone air pollution is identified as one of the main threats bearing upon human health and ecosystems, with 25 000 deaths in 2005 attributed to surface ozone in Europe (IIASA 2013 TSAP Report #10). In addition, there is a concern that climate change could negate ozone pollution mitigation strategies, making them insufficient over the long run and jeopardising chances to meet the long term objective set by the European Union Directive of 2008 (Directive 2008/50/EC of the European Parliament and of the Council of 21 May 2008) (60 ppbv, daily maximum). This effect has been termed the ozone climate penalty. One way of assessing this climate penalty is by driving chemistry-transport models with future climate projections while holding the ozone precursor emissions constant (although the climate penalty may also be influenced by changes in emission of precursors). Here we present an analysis of the robustness of the climate penalty in Europe across time periods and scenarios by analysing the databases underlying 11 articles published on the topic since 2007, i.e. a total of 25 model projections. This substantial body of literature has never been explored to assess the uncertainty and robustness of the climate ozone penalty because of the use of different scenarios, time periods and ozone metrics. Despite the variability of model design and setup in this database of 25 model projection, the present meta-analysis demonstrates the significance and robustness of the impact of climate change on European surface ozone with a latitudinal gradient from a penalty bearing upon large parts of continental Europe and a benefit over the North Atlantic region of the domain. Future climate scenarios present a penalty for summertime (JJA) surface ozone by the end of the century (2071-2100) of at most 5 ppbv. Over European land surfaces, the 95% confidence interval of JJA ozone change is [0.44; 0.64] and [0.99; 1.50] ppbv for the 2041-2070 and 2071-2100 time windows, respectively.

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