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  • 1.
    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)
  • 2.
    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.

  • 3.
    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.

  • 4.
    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.

  • 5.
    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.

  • 6. 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.

  • 7. 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.

  • 8. 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.

  • 9. 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, ISSN 1748-9326, 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.

  • 10. Emberson, L. D.
    et al.
    Bueker, P.
    Ashmore, M. R.
    Mills, G.
    Jackson, L. S.
    Agrawal, M.
    Atikuzzaman, M. D.
    Cinderby, S.
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    Jamir, C.
    Kobayashi, K.
    Oanh, N. T. K.
    Quadir, Q. F.
    Wahid, A.
    A comparison of North American and Asian exposure-response data for ozone effects on crop yields2009In: Atmospheric Environment, ISSN 1352-2310, E-ISSN 1873-2844, Vol. 43, no 12, p. 1945-1953Article, review/survey (Refereed)
    Abstract [en]

    Modelling-based studies to assess the extent and magnitude of ozone (O-3) risk to agriculture in Asia suggest that yield losses of 5-20% for important crops may be common in areas experiencing elevated O-3 concentrations. These assessments have relied on European and North American dose-response relationships and hence assumed an equivalent Asian crop response to O-3 for local cultivars, pollutant conditions and climate. To test this assumption we collated comparable dose-response data derived from fumigation, filtration and EDU experiments conducted in Asia on wheat. rice and leguminous crop species. These data are pooled and compared with equivalent North American dose-response relationships. The Asian data show that at ambient O-3 concentrations found at the study sites (which vary between similar to 35-75 ppb 4-8 h growing season mean), yield losses for wheat, rice and legumes range between 5-48, 3-47 and 10-65%, respectively. The results indicate that Asian grown wheat and rice cultivars are more sensitive to O-3 than the North American dose-response relationships would suggest. For legumes the scatter in the data makes it difficult to reach any equivalent conclusion in relative sensitivities. As such, existing modelling-based risk assessments may have substantially underestimated the scale of the problem in Asia through use of North American derived dose-response relationships. (c) 2009 Elsevier Ltd. All rights reserved.

  • 11.
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    Assessing ground-level ozone (O3) impacts to crops in parts of Asia and southern Africa: The Regional Air Pollution in Developping Countries (RAPIDC) Crops Project.2010In: Air Pollution Health and Environmental Impacts, CRC Press , 2010, p. 421-446Chapter in book (Other academic)
  • 12.
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    Modelling of near-surface ozone over South Asia2008In: Journal of Atmospheric Chemistry, ISSN 0167-7764, E-ISSN 1573-0662, Vol. 59, no 1, p. 61-80Article in journal (Refereed)
    Abstract [en]

    Hourly, three-dimensional, fields of tropospheric ozone have been produced for 12 consecutive months on a domain covering South Asia, using the regional Eulerian off-line chemistry transport model MATCH. The results were compared with background observations to investigate diurnal and seasonal variations of near-surface ozone in the region. MATCH reproduced the seasonality of near-surface ozone at most locations in the area. However, the current, and previous, studies indicate that the model consequently overestimate night-time concentrations, while it occasionally underestimates the day-time, near-surface, ozone concentrations. The lowest monthly-mean concentrations of near-surface ozone are typically experienced in June-September, coincident with the rainy season in most areas. The seasonality is not identical across the domain; some locations have a completely different trend. Large areas in Northern India and Nepal show a secondary minimum during the cold winter season (December-January). High concentrations of near-surface ozone are found over the oceans, close to the Indian subcontinent, due to the less efficient dry deposition to water surfaces; over parts of Tibet due to influence of free tropospheric air and little deposition to snow covered surfaces; and along the Gangetic valley due to the large emissions of precursors in this region. Monthly-mean ozone concentrations in the densely populated northern India range from 30-45 ppb(v). The model results were also used to produce maps of AOT40. The results point towards similar levels of AOT40 in India as in Europe: large areas of India show 3-month AOT40 values above 3 ppm(v) hours.

  • 13.
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    Sulphur simulations for East Asia using the MATCH model with meteorological data from ECMWF2000Report (Other academic)
  • 14.
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    Sulphur simulations for East Asia using the match model with meteorological data from ECMWF2001In: Water, Air and Soil Pollution, ISSN 0049-6979, E-ISSN 1573-2932, Vol. 130, no 1-4, p. 289-294Article in journal (Refereed)
    Abstract [en]

    Sulphur transport and conversion calculations have been conducted over an East Asian domain as part of a model intercomparison exercise. We hereby describe the MATCH model, used in the study, and discuss the results achieved with different model configurations. We find that is often more critical to choose a representative gridbox value than selecting a specific parameter value from the suite available. The modelled, near-surface, atmospheric concentration of total-sulphur (SO2+sulphate) in eastern China is typically 5-10 mug S m(-3), with large areas exceeding 20 mug S m(3). In southern Japan the values range from 2-5 mug S m(-3). Atmospheric SO2 dominates over sulphate near the emission regions while sulphate concentrations are higher over e.g. the western Pacific. The sulphur deposition exceeds several g sulphur m(-2) year m(-1) in large areas of China. Southern Japan receives 0.5-1 S m(-2) year(-1).

  • 15.
    Engardt, Magnuz
    et al.
    SMHI, Research Department, Air quality.
    Alpfjord, Helene
    SMHI, Professional Services.
    Andersson, Camilla
    SMHI, Research Department, Air quality.
    PODY-beräkningar med MATCH Sverigesystemet2016Report (Other academic)
    Abstract [en]

    We have developed a set of programs that enable PODY calculations in the air quality surveillance system MATCH Sverigesystemet. This report gives a brief overview of PODY calculations in general and the MATCH implementation in particular.

    We present results for the receptors generic crops (POD3gen-CR) and generic deciduous trees (POD1gen-DT) for the years 2013-2015 and contrast these with corresponding data from the EMEP-model. The POD3gen-CR values calculated by MATCH feature large inter-annual variations and are significantly higher than the corresponding assessment by the EMEP-model. POD1gen-DT show smaller inter-annual variation and the MATCH and the EMEP-model results correspond better.

    PODY is presented together with other ozone metrics on the SMHI environmental mapping web page (www.smhi.se/klimatdata/miljo/atmosfarskemi) starting from the mapping year 2013.

  • 16.
    Engardt, Magnuz
    et al.
    SMHI, Research Department, Air quality.
    Andersson, Camilla
    SMHI, Research Department, Air quality.
    Bergström, Robert
    SMHI, Research Department, Air quality.
    Modellering av marknära ozon: Regionala och högupplösta tillämpningar av MATCH2011Report (Other academic)
    Abstract [en]

    High concentrations of near-surface ozone in Sweden occur predominantly during spring and summer in the Southwestern part of the country. SMHI’s regional dispersion model, MATCH, complies with the Air Quality Directive on model quality for ozone in the background air of Sweden. This applies both to a European scale application with 44×44 km2 grid squares as well as a highresolution application with 5×5 km2 grid squares. High-resolution modelling marginally improves the statistical scores that describe model quality. Local contribution to ozone exceedances (in suburbs) is probably not a problem in Sweden .Although the MATCH model meets the Air Quality Directive’s demands on model quality does it occasionally miss the episodes with the highest concentrations. This is a severe shortcoming in the modelling system. More accurate information about the emissions of ozone producing substances, in particular in Eastern Europe, and improvements in the model’s description of vertical mixing and deposition is probably needed to improve the model. Two-dimensional variational data analysis could be a tool to achieve a more accurate geographical coverage of ozone-fields in Sweden. This applies, in particular, for AOT40 and number of days exceeding a threshold. MATCH results, including two-dimensional variational data analysis, can be used in combination with measurements to monitor near-surface ozone in Sweden.

  • 17.
    Engardt, Magnuz
    et al.
    SMHI, Research Department, Air quality.
    Bergström, Robert
    SMHI, Research Department, Air quality.
    Andersson, Camilla
    SMHI, Research Department, Air quality.
    Climate and Emission Changes Contributing to Changes in Near-surface Ozone in Europe over the Coming Decades: Results from Model Studies2009In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 38, no 8, p. 452-458Article in journal (Refereed)
    Abstract [en]

    We used an off-line, regional, model of atmospheric transport and chemistry to investigate current and future levels of near-surface ozone and accumulated ozone exposure over a threshold of 40 ppb(v) (AOT40) in Europe. To describe the current situation and enable an evaluation of the model's performance we simulated a number of years around 2000. To assess changes in ozone concentrations due to possible emission changes in Europe, the model was run with the meteorology of the early 2000s and precursor emissions from a set of Clean Air for Europe (CAFE) emissions scenarios. By extrapolation of the observed increase in near-surface O(3) at coastal locations in northwest Europe we constructed model boundaries that were used to simulate the impact of increasing hemispheric background in 2020. To assess changes in ozone concentrations due to climate change, the model was run with recent (2000) emissions but using meteorology from a regional climate model simulating a control (1961-1990) and a future (2021-2050) climate. The results indicate that climate change will have a small impact on ozone concentrations and AOT40 in the Nordic countries. Changes in hemispheric background concentrations and changes in precursor emissions in Europe will have a larger effect on ozone in Northern Europe. The situation is quite different in southern Europe, where climate change is expected to result in a very large increase in near-surface ozone concentrations.

  • 18.
    Engardt, Magnuz
    et al.
    SMHI, Research Department, Air quality.
    Foltescu, Valentin
    SMHI, Research Department, Air quality.
    Luftföroreningar i Europa under framtida klimat2007Report (Other academic)
    Abstract [en]

    In order to investigate the effects of climate change on air quality in Europe, we have utilised the regional CTM (chemistry and transport model) MATCH, forced by meteorology representing future climate conditions but keeping the emissions at their current value. The meteorology is from RCA3, the Rossby Center’s regional climate model (covering all Europe on 50 km × 50 km resolution). RCA3 is, in the current study, run under the SRES A2 emission scenario forced with corresponding climate data from ECHAM4/OPYC3 global model on its boundaries. We have applied our CTM on three different 30-year periods representing current, near- and distant future climate (1961-1990, 2021-2050 and 2071-2100, respectively). Detailed description and validation of the climate model and the CTM is given elsewhere. In the present report we report seasonally-averaged changes in near-surface ozone, secondary inorganic aerosols (SIA) and deposition of sulphur and nitrogen containing species in Europe.The seasonal-mean ozone concentrations are expected to increase considerably (1-2% per decade up to 2050) in central and southern Europe, in particular during summer. The daily maximum concentrations are expected to increase even more than the daily mean concentrations. Northernmost Europe is projected to experience lower ozone concentrations under future climate, especially during spring and autumn. The concentration of SIA will increase dramatically in continental Europe during all seasons except winter. The increase is largest around the Mediterranean during summer. The average summertime concentration of SIA will be 20% higher in 2021-2050 and 50% higher in 2071-2100 compared to current levels as a result of changing the meteorology (drier and warmer conditions in central and southern Europe). The increase in atmospheric SIA concentrations is related to the large decrease in wet deposition of sulphur- and nitrogen containing species, which will be the consequence of climate change in large parts of central and southern Europe. Large areas around the Mediterranean, France, Belgium and the Netherlands will receive 50%, or less, of current nitrogen- and sulphur deposition in 2071-2100 compared to present conditions. The Norwegian coast, on the other hand, is expected to receive more sulphur- and nitrogen deposition due to the anticipated increase in precipitation in this area.

  • 19.
    Engardt, Magnuz
    et al.
    SMHI, Research Department, Air quality.
    Holmen, K
    Model simulations of anthropogenic-CO2 transport to an Arctic monitoring station during winter1999In: Tellus. Series B, Chemical and physical meteorology, ISSN 0280-6509, E-ISSN 1600-0889, Vol. 51, no 2, p. 194-209Article in journal (Refereed)
    Abstract [en]

    We describe, and use, a limited area, 3-dimensional transport model. The model domain is located over the Arctic, but includes the majority of the anthropogenic CO2 emissions in western and eastern Europe, which together make up about 1/3 of the global CO2 emissions. The model is run for several winter periods, using anthropogenic CO2 emissions only, and the results are compared with independent CO2 measurements taken at a monitoring station on Spitsbergen in the high Arctic. We show that the initial concentrations and boundary values of the domain are not crucial for the results, and conclude that most of the measured variability above the winter baseline in CO2 at the Arctic monitoring station emanates from recent CO2 sources within the model domain. From the observed small spatial variability in the monthly mean atmospheric CO2 mixing ratio in the north Atlantic region, we assume that there is only little net exchange between the atmosphere and ocean during the studied periods. Based on the co-variation between CO2 and particulate mass,we hypothesise that most of the measured CO2 variability is due to anthropogenic fossil fuel emissions, although we can not rule out a biogenic CO2 component. Using the transport model, we compare different estimates of fossil-fuel consumption in the mid-latitudes. We find that the industrial centres and the surrounding gas-fields in the lower-Ob region (60 degrees-72 degrees N, 65 degrees-80 degrees E) occasionally have a much larger impact on the CO2 measurements at Spitsbergen than follows from a recent CO2 emission inventory. This implies that there may be an overlooked CO2 source in this region, possibly flaring of gas.

  • 20.
    Engardt, Magnuz
    et al.
    SMHI, Research Department, Air quality.
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Simulations of future sulphur and nitrogen deposition over Europe using meteorological data from three regional climate projections2013In: Tellus. Series B, Chemical and physical meteorology, ISSN 0280-6509, E-ISSN 1600-0889, Vol. 65, article id 20348Article in journal (Refereed)
    Abstract [en]

    We use a regional model of atmospheric chemistry and transport to investigate trends in sulphur and nitrogen deposition over Europe during the first half of the 21st century. To assess changes due to climate change, the model was operated with meteorology from a regional climate model simulating present and future climates. The sensitivity of the deposition calculations to uncertainties in the climate projections was explored by using output from three different climate models. Changes in anthropogenic air pollution emissions in Europe were extracted from the gridded RCP4.5 emission inventory. The modelling systems were evaluated by comparing average modelled precipitation, deposition and concentrations over a 20-year period with observations collected around the year 2000. We conclude that the deposition of sulphur and nitrogen containing species will mainly be governed by changes in European emissions of these species over the period 2000-2050. If future emissions follow the pathway of the RCP4.5 scenario, Europe can expect significantly lower deposition of sulphur and oxidised nitrogen in 2050 compared to 2000. For reduced nitrogen, large areas of western Europe will receive considerably more deposition in 2050 than in 2000, due to feedback of decreased sulphur concentrations on the atmospheric turnover time of reduced nitrogen. Domain averaged reductions of total deposition from 2000 to 2050 are 63, 41 and 0.9% for sulphur, oxidised-and reduced nitrogen, respectively. Climate change results in decreased wet deposition of sulphur and reduced nitrogen leading to increased atmospheric turnover time of these species. Climate and emission changes lead to decreased atmospheric turnover times of reduced nitrogen but increased atmospheric turnover times of sulphur and oxidised nitrogen. These relations are likely leading to altered source-receptor relations in the future.

  • 21.
    Engardt, Magnuz
    et al.
    SMHI, Research Department, Air quality.
    Leong, C P
    Regional modelling of anthropogenic sulphur in Southeast Asia2001In: Atmospheric Environment, ISSN 1352-2310, E-ISSN 1873-2844, Vol. 35, no 34, p. 5935-5947Article in journal (Refereed)
    Abstract [en]

    A co-operative research project between the Malaysian Meteorological Service (MMS) and the Swedish Meteorological and Hydrological Institute (SMHI) focussing on the usage of an atmospheric transport and chemistry model, has just been initiated. Here, we describe the main features of the dispersion model and discuss a first set of calculations in light of available measurements of sulphuric species in Southeast Asia. According to our results, anthropogenic sulphur concentrations and depositions are particularly high near the large cities of the region, around a metal smelter in the southern Philippines, and in a region extending from northern Vietnam into southeastern China. These areas coincide with the high-emissions regions of Southeast Asia and we tentatively conclude that regional transport of acidifying species is not as far-reaching as in the mid-latitudes. From our calculations, and from supporting measurements we conclude that most of rural Southeast Asia is not yet severely affected by anthropogenic sulphur, but given the rapid rate of economical development in this region the situation may deteriorate quickly. Areas that are particularly at risk include the large cities, northern Vietnam, most of central Thailand, most of peninsular Malaysia, eastern Sumatra and parts of Java, all of which receive total-sulphur depositions in excess of 0.5 g S m(-2) yr(-1). Our model simulates sulphate in precipitation in accordance with measurements, but it has a tendency to overestimate atmospheric SO2. It remains to be investigated whether this is a problem in the model formulation or a result of unrepresentative sampling. An immediate continuation of this study should be performed with higher spatial resolution than the currently used 100 x 100 km(2). Other imperfections in this model study, which should be addressed in future work, include parameterised vertical transport in deep convective clouds, the influence of natural emissions (primarily from volcanoes) on the concentration and deposition of sulphuric species, and the year-to-year variability of the driving meteorological conditions. (C) 2001 Elsevier Science Ltd. All rights reserved.

  • 22.
    Engardt, Magnuz
    et al.
    SMHI, Research Department, Air quality.
    Simpson, David
    Schwikowski, Margit
    Granat, Lennart
    Deposition of sulphur and nitrogen in Europe 1900-2050. Model calculations and comparison to historical observations2017In: Tellus. Series B, Chemical and physical meteorology, ISSN 0280-6509, E-ISSN 1600-0889, Vol. 69, article id 1328945Article in journal (Refereed)
  • 23.
    Engardt, Magnuz
    et al.
    SMHI, Research Department, Air quality.
    Siniarovina, U
    Khairul, N I
    Leong, C P
    Country to country transport of anthropogenic sulphur in Southeast Asia2005In: Atmospheric Environment, ISSN 1352-2310, E-ISSN 1873-2844, Vol. 39, no 28, p. 5137-5148Article in journal (Refereed)
    Abstract [en]

    The MATCH model-driven by archived meteorological data from the ECMWF-has been used to study the long-range transport of pollutants in Southeast Asia during the year 2000. We have specifically investigated the atmospheric export and import of anthropogenic sulphur between nine countries in Southeast Asia as well as the import to these countries from the boundaries of our model domain, from southern China, and from international shipping in the surrounding waters. Compared to the conditions at the mid-latitudes (Europe, North America and East Asia), we find less long-range transport in this part of the world. In all countries in the region (except those with very small area, i.e. Singapore and Brunei), did the major part of the domestic emissions (60-70%) fall down on the emitting country itself. The fraction of the countries own emissions contributing to the total, annually accumulated, national deposition varied from 10% for Laos-which is a country with small emissions neighbouring large emitters-to 80-90% in countries not surrounded by significant emitters (i.e. Thailand, Indonesia, Singapore and Brunei). Sensitivity tests were performed to explore the uncertainties in the model simulations and to investigate to what extent the current results could be used for source-receptor relationships in the future, when the magnitude and location of the emissions may be different. We found that the general feature-with relatively little long-range transport of sulphur-will not be altered, while the absolute magnitude of the deposition in areas downwind of large emitters could change considerably if certain model parameters, or the emission patterns are changed. This is particularly true in light of the seasonal variation of the deposition pathways. The atmospheric import of anthropogenic sulphur from specific countries can vary by an order of magnitude between different months. Incidentally, a decrease in import from one country during a certain period is often compensated by a roughly equal increase of the import from another country during the same time. (c) 2005 Elsevier Ltd. All rights reserved.

  • 24.
    Gidhagen, Lars
    et al.
    SMHI, Research Department, Air quality.
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    Lovenheim, Boel
    Johansson, Christer
    Modeling Effects of Climate Change on Air Quality and Population Exposure in Urban Planning Scenarios2012In: Advances in Meteorology, ISSN 1687-9309, E-ISSN 1687-9317, article id 240894Article in journal (Refereed)
    Abstract [en]

    We employ a nested system of global and regional climate models, linked to regional and urban air quality chemical transport models utilizing detailed inventories of present and future emissions, to study the relative impact of climate change and changing air pollutant emissions on air quality and population exposure in Stockholm, Sweden. We show that climate change only marginally affects air quality over the 20-year period studied. An exposure assessment reveals that the population of Stockholm can expect considerably lower NO2 exposure in the future, mainly due to reduced local NOx emissions. Ozone exposure will decrease only slightly, due to a combination of increased concentrations in the city centre and decreasing concentrations in the suburban areas. The increase in ozone concentration is a consequence of decreased local NOx emissions, which reduces the titration of the long-range transported ozone. Finally, we evaluate the consequences of a planned road transit project on future air quality in Stockholm. The construction of a very large bypass road (including one of the largest motorway road tunnels in Europe) will only marginally influence total population exposure, this since the improved air quality in the city centre will be complemented by deteriorated air quality in suburban, residential areas.

  • 25. Han, Z.
    et al.
    Sakurai, T.
    Ueda, H.
    Carmichael, G. R.
    Streets, D.
    Hayami, H.
    Wang, Z.
    Holloway, T.
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    Hozumi, Y.
    Park, S. U.
    Kajino, M.
    Sartelet, K.
    Fung, C.
    Bennet, Cecilia
    SMHI, Research Department, Air quality.
    Thongboonchoo, N.
    Tang, Y.
    Chang, A.
    Matsuda, K.
    Amann, M.
    MICS-Asia II: Model intercomparison and evaluation of ozone and relevant species2008In: Atmospheric Environment, ISSN 1352-2310, E-ISSN 1873-2844, Vol. 42, no 15, p. 3491-3509Article in journal (Refereed)
    Abstract [en]

    Eight regional Eulerian chemical transport models (CTMs) are compared with each other and with an extensive set of observations including ground-level concentrations from EANET, ozone soundings from JMA and vertical profiles from the TRACE-P experiment to evaluate the models' abilities in simulating O(3) and relevant species (SO(2), NO, NO(2), HNO(3) and PAN) in the troposphere of East Asia and to look for similarities and differences among model performances. Statistical analysis is conducted to help estimate the consistency and discrepancy between model simulation and observation in terms of various species, seasons, locations, as well as attitude ranges. In general, all models show a good skill of simulating SO(2) for both ground level and the lower troposphere, although two of the eight models systematically overpredict SO(2) concentration. The model skills for O(3) vary largely with region and season. For ground-level O(3), model results are best correlated with observations in July 2001. Comparing with O(3) soundings measured in the afternoon reveals the best consistency among models in March 2001 and the largest disparity in O(3) magnitude in July 2001, although most models produce the best correlation in July as well. In terms of the statistics for the four flights of TRACE-P experiment, most models appear to be able to accurately capture the variability in the lower troposphere. The model performances for NO(x) are relatively poor, with lower correlation and with almost all models tending to underpredict NO(x) levels, due to larger uncertainties in either emission estimates or complex chemical mechanism represented. All models exhibit larger RMSE at altitudes < 2 km than 2-5.5 kin, mainly due to a consistent tendency of these models towards underprediction of the magnitude of intense plumes that often originate from near surface. Relatively lower correlation at altitudes 2-5.5 km may be attributed to the models' limitation in representing convection or potential chemical processes. Most of the key features in species distribution have been consistently reproduced by the participating models, such as the O(3) enhancement in the western Pacific Ocean in March and in northeast Asia in July, respectively, although the absolute model values may differ considerably from each other. Large differences are found among models in the southern parts of the domain for all the four periods, including southern China and northern parts of some Southeast Asia countries where the behaviors of chemical components and the ability of these models are still not clearly known because of a lack of observational databases. (C) 2007 Elsevier Ltd. All rights reserved.

  • 26. Hayami, Hiroshi
    et al.
    Sakurai, T.
    Han, Z.
    Ueda, H.
    Carmichael, G. R.
    Streets, D.
    Holloway, T.
    Wang, Z.
    Thongboonchoo, N.
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    Bennet, Cecilia
    SMHI, Research Department, Air quality.
    Fung, C.
    Chang, A.
    Park, S. U.
    Kajino, M.
    Sartelet, K.
    Matsuda, K.
    Amann, M.
    MICS-Asia II: Model intercomparison and evaluation of particulate sulfate, nitrate and ammonium2008In: Atmospheric Environment, ISSN 1352-2310, E-ISSN 1873-2844, Vol. 42, no 15, p. 3510-3527Article in journal (Refereed)
    Abstract [en]

    Eight chemical transport models participate in a model intercomparison study for East Asia, MICS-Asia II. This paper analyzes calculated results for particulate matter of sulfate, nitrate and ammonium through comparisons with each other and with monthly measurements at EANET (the acid deposition monitoring network in East Asia) and daily measurements at Fukue, Japan. To the EANET measurements, model ensemble means better agree with model individual results for sulfate and total ammonium, although total nitrate is consistently and considerably underestimated. To measurements at Fukue, the models show better agreement than for the EANET measurements. This is likely because Fukue is centered in many of the model domains, whereas the EANET stations are mostly in Southeast Asia and Russia. Moreover, it would be important that Fukue is in Northeast Asia, where the emission inventory is more reliable than Southeast Asia. The model-model comparisons are made in view of the total amount in the atmosphere, vertical profile, coefficient of variation in surface concentrations, and transformation changes with distance. All the models show reasonable tendencies in vertical profiles and composition ratios. However, total amounts in the atmosphere are discrepant among the models. The consistency of the total amount in the atmosphere would influence source-receptor analysis. It seems that model results would be consistent, if the models take into account the primitive processes like emission, advection/diffusion, chemical transformation and dry/wet deposition, no matter the processes are modeled simply or comprehensively. Through the comparison study, we learned that it would be difficult to find any problems from one comparison (model-observation comparison with one data or many but at one station or in a short period). Modelers tend to examine model performances only from model-observation comparisons. However, taking budget in a certain or whole model domain would be important, before the models are applied to source-receptor analysis. (C) 2007 Elsevier Ltd. All rights reserved.

  • 27. Hole, Lars
    et al.
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    Climate change impact on atmospheric nitrogen deposition in northwestern Europe: A model study2008In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 37, no 1, p. 9-17Article in journal (Refereed)
    Abstract [en]

    A high-resolution chemical transport model, driven by meteorology representing current and future climate, was used to investigate the effects of possible future changes in climate on nitrogen deposition in northwestern Europe. The model system was able to resolve the climatology of precipitation and chemical properties observed in northern Europe during the 1980s, albeit with some underestimation of the temporal and spatial variability of meteorological parameters and chemical components. The results point toward a substantial increase (30% or more) in nitrogen deposition over western Norway as a consequence of increasing precipitation but more moderate changes for other areas. Deposition of oxidized nitrogen will increase more than the deposition of reduced nitrogen. Over Sweden, oxidized nitrogen will increase only marginally and reduced nitrogen will decrease, although annual precipitation is expected to increase here as well. This is probably because more reduced nitrogen will be removed further west in Scandinavia because of the strong increase in precipitation along the Norwegian coast. The total deposition of oxidized nitrogen over Norway is expected to increase from 96 Gg N y(-1) during the current climate to 107 Gg N y(-1) by 2100 due only to changes in climate. The corresponding values for Sweden are more modest, from 137 Gg N y(-1) to 139 Gg N y(-1).

  • 28. Holloway, Tracey
    et al.
    Sakurai, Tatsuya
    Han, Zhiwei
    Ehlers, Susanna
    Spak, Scott N.
    Horowitz, Larry W.
    Carmichael, Gregory R.
    Streets, David G.
    Hozumi, Y.
    Ueda, Hiromasa
    Park, S. U.
    Fung, Christopher
    Kajino, M.
    Thongboonchoo, Narisara
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    Bennet, Cecilia
    SMHI, Research Department, Air quality.
    Hayami, Hiroshi
    Sartelet, Karine
    Wang, Zifa
    Matsuda, K.
    Amann, Markus
    MICS-Asia II: Impact of global emissions on regional air quality in Asia2008In: Atmospheric Environment, ISSN 1352-2310, E-ISSN 1873-2844, Vol. 42, no 15, p. 3543-3561Article in journal (Refereed)
    Abstract [en]

    This study quantifies the seasonality and geographic variability of global pollutant inflow to Asia. Asia is often looked to as a major source of intercontinental air pollution transport with rising emissions and efficient pollutant export processes. However, the degree to which foreign emissions have been imported to Asia has not been thoroughly examined. The Model Inter-Comparison Study for Asia (MICS-Asia) is an international collaboration to study air pollution transport and chemistry in Asia. Using the global atmospheric chemistry Model of Ozone and Related Tracers (MOZART v. 2.4), and comparing results with a suite of regional models participating in MICS-Asia, we find that imported O-3 contributes significantly throughout Asia. The choice of upper boundary condition is found to be particularly important for O-3, even for surface concentrations. Both North America and Europe contribute to ground-level O-3 concentrations throughout the region, though the seasonality of these two sources varies. North American contributions peak at over 10% of monthly mean O-3 during winter months in East Asia, compared to Europe's spring- and autumn-maxima (5-8%). In comparison to observed data from the Acid Deposition Monitoring Network in East Asia (EANET), MOZART concentrations for 03 generally fall within the range of the MICS models, but MOZART is unable to capture the fine spatial variability of shorter-lived species as well as the regional models. (C) 2007 Elsevier Ltd. All rights reserved.

  • 29. Karlsson, Per Erik
    et al.
    Klingberg, Jenny
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    Andersson, Camilla
    SMHI, Research Department, Air quality.
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Karlsson, Gunilla Pihl
    Pleijel, Hakan
    Past, present and future concentrations of ground-level ozone and potential impacts on ecosystems and human health in northern Europe2017In: SCIENCE OF THE TOTAL ENVIRONMENT, ISSN 0048-9697, Vol. 576, p. 22-35Article in journal (Refereed)
  • 30.
    Kjellström, Erik
    et al.
    SMHI, Research Department, Climate research - Rossby Centre.
    Holmen, K
    Eneroth, K
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    Summertime Siberian CO2 simulations with the regional transport model MATCH: a feasibility study of carbon uptake calculations from EUROSIB data2002In: Tellus. Series B, Chemical and physical meteorology, ISSN 0280-6509, E-ISSN 1600-0889, Vol. 54, no 5, p. 834-849Article in journal (Refereed)
    Abstract [en]

    Biogenic surface fluxes Of CO2 over Europe and Siberia are implemented in the regional tracer transport model MATCH. A systematic comparison between simulated and observed CO2 fluxes and mixing ratios is performed for two observational sites in Russia taking into account both surface observations and vertical profiles of meteorological parameters and CO2 in the lowest 3 km from the summer months in 1998. We find that the model is able to represent meteorological parameters as temperature, humidity and planetary boundary layer height consistent with measurements. Further, it is found that the simulated surface CO2 fluxes capture a large part of the observed variability on a diurnal time scale. On a synoptic time scale the agreement between observations and simulation is poorer which leads to a disagreement between time series of observed and simulated CO2 mixing ratios. However, the model is able to realistically simulate the vertical gradient in CO2 in the lowest few kilometres. The vertical variability is studied by means of trajectory analysis together with results from the MATCH model. This analysis clearly illustrates some problems in deducing CO2 fluxes from CO2 mixing ratios measured in single vertical profiles. Studies of the regional variability Of CO2 in the model domain show that there exists no ideal vertical level for detecting the terrestrial signal Of CO2 in the free troposphere. The strongest terrestrial signal is found in the boundary layer above the lowest few hundred metres. Nevertheless, this terrestrial signal is small, and during the simulated period it is not possible to detect relative variations in the surface fluxes smaller than 20%. We conclude that a regional flux cannot be determined from single ground stations or a few vertical profiles, mainly due to synoptic scale variability in transport and in CO2 surface fluxes.

  • 31.
    Klein, Thomas
    et al.
    SMHI, Core Services.
    Karlsson, Per-Erik
    IVL Swedish Environmental Research Institute.
    Andersson, Stefan
    SMHI, Research Department, Air quality.
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    Sjöberg, Karin
    IVL Swedish Environmental Research Institute.
    Assessing and improving the Swedish forecast and information capabilities for ground-level ozone2011Report (Other academic)
    Abstract [en]

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

  • 32. Klingberg, J.
    et al.
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    Karlsson, P. E.
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Pleijel, H.
    Declining ozone exposure of European vegetation under climate change and reduced precursor emissions2014In: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 11, no 19, p. 5269-5283Article in journal (Refereed)
    Abstract [en]

    The impacts of changes in ozone precursor emissions as well as climate change on the future ozone exposure of the vegetation in Europe were investigated. The ozone exposure is expressed as AOT40 (Accumulated exposure Over a Threshold of 40 ppb O-3) as well as PODY (Phytotoxic Ozone Dose above a threshold Y). A new method is suggested to express how the length of the period during the year when coniferous and evergreen trees are sensitive to ozone might be affected by climate change. Ozone precursor emission changes from the RCP4.5 scenario were combined with climate simulations based on the IPCC SRES A1B scenario and used as input to the Eulerian Chemistry Transport Model MATCH from which projections of ozone concentrations were derived. The ozone exposure of vegetation over Europe expressed as AOT40 was projected to be substantially reduced between the periods 1990-2009 and 2040-2059 to levels which are well below critical levels used for vegetation in the EU directive 2008/50/EC as well as for crops and forests used in the LRTAP convention, despite that the future climate resulted in prolonged yearly ozone sensitive periods. The reduction in AOT40 was mainly driven by the emission reductions, not changes in the climate. For the toxicologically more relevant POD1 index the projected reductions were smaller, but still significant. The values for POD1 for the time period 2040-2059 were not projected to decrease to levels which are below critical levels for forest trees, represented by Norway spruce. This study shows that substantial reductions of ozone precursor emissions have the potential to strongly reduce the future risk for ozone effects on the European vegetation, even if concurrent climate change promotes ozone formation.

  • 33. Klingberg, J.
    et al.
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    Uddling, J.
    Karlsson, P. E.
    Pleijel, H.
    Ozone risk for vegetation in the future climate of Europe based on stomatal ozone uptake calculations2011In: Tellus. Series A, Dynamic meteorology and oceanography, ISSN 0280-6495, E-ISSN 1600-0870, Vol. 63, no 1, p. 174-187Article in journal (Refereed)
  • 34. Kulshrestha, Monika J.
    et al.
    Singh, Ruchi
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    Ambient and Episodic Levels of Metals in PM10 Aerosols and Their Source Apportionment in Central Delhi, India2016In: JOURNAL OF HAZARDOUS TOXIC AND RADIOACTIVE WASTE, ISSN 2153-5493, Vol. 20, no 4, article id UNSP A4014002Article in journal (Refereed)
  • 35. Kulshrestha, U C
    et al.
    Granat, L
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    Rodhe, H
    Review of precipitation monitoring studies in India - a search for regional patterns2005In: Atmospheric Environment, ISSN 1352-2310, E-ISSN 1873-2844, Vol. 39, no 38, p. 7403-7419Article, review/survey (Refereed)
    Abstract [en]

    This study is a review of rain chemistry measurements reported in India. Data from nearly 100 stations were reviewed with regard to sampling location, sampling method and chemical analyses. Some characteristic differences were found between the concentrations in different environments in line with known distributions of emissions. This was most clearly seen for with median concentration increasing from rural and suburban to urban and industrial environments, with concentrations of HCO3- and H+ varying the opposite way. Ca2+ concentration was higher in suburban and industrial environments compared to rural and urban. Concentration of NH4+ was lower in rural than in the other locations. Sea salt const, concentration (Na+ and Cl- in approximately 'Jut proport ion) was higher in urban than in rural locations at the same distance from the sea. The reported data from rural and Suburban locations were used to derive large-scale concentration fields over India. With knowledge of emission fields and with the aid of output from a regional transport model it was possible to see some limited spatial resemblance between modelled and observed concentrations in cases of SO2, NH4+, NO3- and SO42-. For soil dust, Current models are very crude but here some resemblance Could be seen: primarily limited spatial resemblance with Ca2+, pH and HCO3- with generally increasing values towards NW. Four sites, at least two of them located in forested environments, had a mean rainwater pH close to neutral (concentration or H+ and HCO3- about equal). Other sites had oil average an excess of HCO3-, becoming very substantial in the direction of the Thar Desert in NW India. With this review we conclude that there is a need to better assure the quality of the data with regard to sampling methods, chemical analyses and spatial representativeness. (c) 2005 Elsevier Ltd. All rights reserved.

  • 36. Kuylenstierna, J C I
    et al.
    Hicks, W K
    Cinderby, S
    Vallack, H W
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    Variability in mapping acidification risk scenarios for terrestrial ecosystems in Asian countries2001In: Water, Air and Soil Pollution, ISSN 0049-6979, E-ISSN 1573-2932, Vol. 130, no 1-4, p. 1175-1180Article in journal (Refereed)
    Abstract [en]

    Acidification has the potential to become a widespread problem in parts of Asia. Just how widespread this risk may be is discussed by comparing sulphur deposition to critical load estimates, taking into account neutralising base cation deposition from soil dust. Two scenarios for the sulphur emission in 2025 are used as inputs to the MATCH atmospheric transfer model to estimate sulphur deposition scenarios. Net acidic deposition using a low and high base cation deposition input is compared to a map of sensitivity of terrestrial ecosystems to acidic deposition. Two ranges of critical loads assigned to this sensitivity reap are used. The variability in the maps showing risks of acidification using low and high estimates for critical loads and base cation deposition for two different development pathways is discussed. Certain areas are shown to be at risk in all cases whereas others are very sensitive to the values used to estimate risk.

  • 37. Lacressonniere, Gwendoline
    et al.
    Foret, Gilles
    Beekmann, Matthias
    Siour, Guillaume
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    Gauss, Michael
    Watson, Laura
    Andersson, Camilla
    SMHI, Research Department, Air quality.
    Colette, Augustin
    Josse, Beatrice
    Marecal, Virginie
    Nyiri, Agnes
    Vautard, Robert
    Impacts of regional climate change on air quality projections and associated uncertainties2016In: Climatic Change, ISSN 0165-0009, E-ISSN 1573-1480, Vol. 136, no 2, p. 309-324Article in journal (Refereed)
  • 38.
    Langner, Joakim
    et al.
    SMHI, Research Department, Air quality.
    Andersson, Camilla
    SMHI, Research Department, Air quality.
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    Atmospheric input of nitrogen to the Baltic Sea basin: present situation, variability due to meteorology and impact of climate change2009In: Boreal environment research, ISSN 1239-6095, E-ISSN 1797-2469, Vol. 14, no 1, p. 226-237Article in journal (Refereed)
    Abstract [en]

    We present estimates of the present and future deposition of atmospheric nitrogen into the Baltic Sea made using the Eulerian chemical transport model MATCH, and compare these with earlier model estimates. The average total nitrogen deposition for periods of five to ten years from 1992 to 2001 was estimated to be in the range of 261-300 Gg N yr(-1). The deposition across the whole catchment area for 2001 was estimated to be 1.55-1.73 Tg N yr(-1). Inter-annual variability of nitrogen deposition into the Baltic Sea was calculated to be in the range of 5.1%-8.0%. Investigating one climate change scenario using emissions for year 2000 indicated a rather small impact on total deposition of nitrogen due to climate change, i.e. increase of total nitrogen deposition by similar to 5% by the end of the 21st century as compared with present conditions. The combined effect of climate change and future changes in anthropogenic emissions of nitrogen to the atmosphere remains an open question. Additional climate change scenarios using different combinations of global and regional climate models and greenhouse gas emission scenarios need to be explored.

  • 39.
    Langner, Joakim
    et al.
    SMHI, Research Department, Air quality.
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    Andersson, Camilla
    SMHI, Research Department, Air quality.
    European summer surface ozone 1990-21002012In: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 12, no 21, p. 10097-10105Article in journal (Refereed)
    Abstract [en]

    The impact of climate change and changes in ozone precursor emission on summer surface ozone in Europe was studied using a regional CTM over the period 1990 to 2100. Two different climate simulations under the SRES A1B scenario together with ozone precursor emission changes from the RCP4.5 scenario were used as model input. In southern Europe regional climate change leads to increasing surface ozone concentrations during April-September, but projected emission reductions in Europe have a stronger effect, resulting in net reductions of surface ozone concentrations. In northern Europe regional climate change decreases surface O-3 and reduced European emissions acts to further strengthen this trend also when including increasing hemispheric background concentrations. The European O-3 precursor emission reductions in RCP4.5 are substantial and it remains to be seen if these reductions can be achieved. There is substantial decadal variability in the simulations forced by climate variability which is important to consider when looking at changes in surface O-3 concentrations, especially until the first half of the 21st century. In order to account for changes in background O-3 future regional model studies should couple global (hemispheric) and regional CTMs forced by a consistent set of meteorological and precursor emission data.

  • 40.
    Langner, Joakim
    et al.
    SMHI, Research Department, Air quality.
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    Baklanov, A.
    Christensen, J. H.
    Gauss, M.
    Geels, C.
    Hedegaard, G. B.
    Nuterman, R.
    Simpson, D.
    Soares, J.
    Sofiev, M.
    Wind, P.
    Zakey, A.
    A multi-model study of impacts of climate change on surface ozone in Europe2012In: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 12, no 21, p. 10423-10440Article in journal (Refereed)
    Abstract [en]

    The impact of climate change on surface ozone over Europe was studied using four offline regional chemistry transport models (CTMs) and one online regional integrated climate-chemistry model (CCM), driven by the same global projection of future climate under the SRES A1B scenario. Anthropogenic emissions of ozone precursors from RCP4.5 for year 2000 were used for simulations of both present and future periods in order to isolate the impact of climate change and to assess the robustness of the results across the different models. The sensitivity of the simulated surface ozone to changes in climate between the periods 20002009 and 2040-2049 differs by a factor of two between the models, but the general pattern of change with an increase in southern Europe is similar across different models. Emissions of isoprene differ substantially between different CTMs ranging from 1.6 to 8.0 Tg yr(-1) for the current climate, partly due to differences in horizontal resolution of meteorological input data. Also the simulated change in total isoprene emissions varies substantially across models explaining part of the different climate response on surface ozone. Ensemble mean changes in summer mean ozone and mean of daily maximum ozone are close to 1 ppb(v) in parts of the land area in southern Europe. Corresponding changes of 95-percentiles of hourly ozone are close to 2 ppb(v) in the same region. In northern Europe ensemble mean for mean and daily maximum show negative changes while there are no negative changes for the higher percentiles indicating that climate impacts on O-3 could be especially important in connection with extreme summer events.

  • 41. Leck, C
    et al.
    Heintzenberg, J
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    A meridional profile of the chemical composition of submicrometre particles over the East Atlantic Ocean: regional and hemispheric variabilities2002In: Tellus. Series B, Chemical and physical meteorology, ISSN 0280-6509, E-ISSN 1600-0889, Vol. 54, no 4, p. 377-394Article in journal (Refereed)
    Abstract [en]

    Within the framework of SWEDARP (Swedish Antarctic Program) 92,93 an aerosol sampling program was carried out on board of M/S Palarbjorn which carried staff and material to the Nordic Antarctic Field exercises during the Austral summer 1992/1993. The cruise started 11 November 1992 from Oslo, went via Cape Town to Antarctica, and then back to Cape Town ,here the ship arrived on 4 January 1993. During the cruise, a meridional profile of physical and chemical submicrometre aerosol properties was derived covering the East Atlantic Ocean from 60degreesN to 70degreesS. The multicomponent aerosol data set combined with a trajectory analysis revealed a systematic meridional distribution of aerosol sources over the Atlantic that covered European and African continental Plumes and, South of 15degreesS, a largely biologically controlled marine aerosol. Median number concentrations calculated over the whole cruise spanned a factor of 20 between 2000 and 100 cm(-3), while total analyzed mass concentrations ranged between 7800 and 40 ng m(3). From the biologically dominated subset of the data in the southern hemisphere, relationships were developed that allowed an apportionment of the observed sulfate and ammonium concentration to biogenic and anthropogenic Sources over the whole meridional aerosol profile.

  • 42. Markakis, Konstantinos
    et al.
    Valari, Myrto
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    Lacressonniere, Gwendoline
    Vautard, Robert
    Andersson, Camilla
    SMHI, Research Department, Air quality.
    Mid-21st century air quality at the urban scale under the influence of changed climate and emissions - case studies for Paris and Stockholm2016In: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 16, no 4, p. 1877-1894Article in journal (Refereed)
    Abstract [en]

    Ozone, PM10 and PM2.5 concentrations over Paris, France and Stockholm, Sweden were modelled at 4 and 1 km horizontal resolutions respectively for the present and 2050 periods employing decade-long simulations. We account for large-scale global climate change (RCP-4.5) and fine-resolution bottom-up emission projections developed by local experts and quantify their impact on future pollutant concentrations. Moreover, we identify biases related to the implementation of regional-scale emission projections by comparing modelled pollutant concentrations between the fine-and coarse-scale simulations over the study areas. We show that over urban areas with major regional contribution (e.g. the city of Stockholm) the bias related to coarse-scale projections may be significant and lead to policy misclassification. Our results stress the need to better understand the mechanism of bias propagation across the modelling scales in order to design more successful local-scale strategies. We find that the impact of climate change is spatially homogeneous in both regions, implying strong regional influence. The climate benefit for ozone (daily mean and maximum) is up to 5% for Paris and 2% for Stockholm city. The climate benefit on PM2.5 and PM10 in Paris is between 5 and 10 %, while for Stockholm we estimate mixed trends of up to 3% depending on season and size class. In Stockholm, emission mitigation leads to concentration reductions up to 15% for daily mean and maximum ozone and 20% for PM. Through a sensitivity analysis we show that this response is entirely due to changes in emissions at the regional scale. On the contrary, over the city of Paris (VOC-limited photochemical regime), local mitigation of NO x emissions increases future ozone concentrations due to ozone titration inhibition. This competing trend between the respective roles of emission and climate change, results in an increase in 2050 daily mean ozone by 2.5% in Paris. Climate and not emission change appears to be the most influential factor for maximum ozone concentration over the city of Paris, which may be particularly interesting from a health impact perspective.

  • 43. Otero, Noelia
    et al.
    Sillmann, Jana
    Mar, Kathleen A.
    Rust, Henning W.
    Solberg, Sverre
    Andersson, Camilla
    SMHI, Research Department, Air quality.
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    Bergström, Robert
    SMHI, Research Department, Air quality.
    Bessagnet, Bertrand
    Colette, Augustin
    Couvidat, Florian
    Cuvelier, Cournelius
    Tsyro, Svetlana
    Fagerli, Hilde
    Schaap, Martijn
    Manders, Astrid
    Mircea, Mihaela
    Briganti, Gino
    Cappelletti, Andrea
    Adani, Mario
    D'Isidoro, Massimo
    Pay, Maria-Teresa
    Theobald, Mark
    Vivanco, Marta G.
    Wind, Peter
    Ojha, Narendra
    Raffort, Valentin
    Butler, Tim
    A multi-model comparison of meteorological drivers of surface ozone over Europe2018In: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 18, no 16, p. 12269-12288Article in journal (Refereed)
  • 44. Pleijel, Hakan
    et al.
    Klingberg, Jenny
    Karlsson, Gunilla Pihl
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    Karlsson, Per Erik
    Surface Ozone in the Marine Environment-Horizontal Ozone Concentration Gradients in Coastal Areas2013In: Water, Air and Soil Pollution, ISSN 0049-6979, E-ISSN 1573-2932, Vol. 224, no 7, article id 1603Article in journal (Refereed)
    Abstract [en]

    Spring/summer surface ozone concentrations, [O-3], in coastal environments were investigated: (1) by comparison of coastal and inland monitoring stations with data from a small island >5 km off the coast of southwest Sweden, (2) as a gradient from the coast towards inland in southernmost Sweden. Further, results from the chemical transport model MATCH were used to assess the marine influence on [O-3]. It was hypothesised that [O-3] is higher on the small island compared to the coast, especially during night and in offshore wind. Another hypothesis was that [O-3] declines from the coast towards inland. Our hypotheses were based on observations that the deposition velocity of O-3 to sea surfaces is lower than to terrestrial surfaces, and that vertical air mixing is stronger in the marine environment, especially during night. The island experienced 10 % higher [O-3] compared to the coast. This difference was larger with offshore (15 %) than onshore wind (9 %). The concentration difference between island and coast was larger during night, but prevailed during day and could not be explained by differences in [NO2] between the sites. The difference in [O-3] between the island and the inland site was 20 %. Higher [O-3] over the sea, especially during night, was reproduced by MATCH. In the gradient study, [O-3] declined from the coast towards inland. Both [O-3] and [NO2] were elevated at the coast, indicating that the gradient in [O-3] from the coast was not caused by NO titration. The conclusions were that surface [O-3] in marine environments is higher than in coastal, and higher in coastal than inland areas, especially during night.

  • 45.
    Robertson, Lennart
    et al.
    SMHI, Research Department, Air quality.
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    An Eulerian limited-area atmospheric transport model1999In: Journal of applied meteorology (1988), ISSN 0894-8763, E-ISSN 1520-0450, Vol. 38, no 2, p. 190-210Article in journal (Refereed)
    Abstract [en]

    A limited-area, offline, Eulerian atmospheric transport model has been developed. The model is based on a terrain-following vertical coordinate and a mass-conserving, positive definite advection scheme with small phase and amplitude errors. The objective has been to develop a flexible, all purpose offline model. The model includes modules for emission input, vertical turbulent diffusion, and deposition processes. The model can handle an arbitrary number of chemical components and provides a framework for inclusion of modules describing physical and chemical transformation processes between different components. Idealized test cases, as well as simulations of the atmospheric distribution of Rn-222, demonstrate the ability of the model to meet the requirements of mass conservation and positiveness and to produce realistic simulations of a simple atmospheric tracer.

  • 46.
    Robertson, Lennart
    et al.
    SMHI, Research Department, Air quality.
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    MATCH - Meso-scale Atmospheric Transport and Chemistry modelling system1996Report (Other academic)
  • 47. Simpson, D.
    et al.
    Andersson, Camilla
    SMHI, Research Department, Air quality.
    Christensen, J. H.
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    Geels, C.
    Nyiri, A.
    Posch, M.
    Soares, J.
    Sofiev, M.
    Wind, P.
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Impacts of climate and emission changes on nitrogen deposition in Europe: a multi-model study2014In: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 14, no 13, p. 6995-7017Article in journal (Refereed)
    Abstract [en]

    The impact of climate and emissions changes on the deposition of reactive nitrogen (Nr) over Europe was studied using four offline regional chemistry transport models (CTMs) driven by the same global projection of future climate over the period 2000-2050. Anthropogenic emissions for the years 2005 and 2050 were used for simulations of both present and future periods in order to isolate the impact of climate change, hemispheric boundary conditions and emissions, and to assess the robustness of the results across the different models. The results from these four CTMs clearly show that the main driver of future N-deposition changes is the specified emission change. Under the specified emission scenario for 2050, emissions of oxidised nitrogen were reduced substantially, whereas emissions of NH3 increase to some extent, and these changes are largely reflected in the modelled concentrations and depositions. The lack of sulfur and oxidised nitrogen in the future atmosphere results in a much larger fraction of NHx being present in the form of gaseous ammonia. Predictions for wet and total deposition were broadly consistent, although the three fine-scale models resolve European emission areas and changes better than the hemisphericscale model. The biggest difference in the models is for predictions of individual N compounds. One model (EMEP) was used to explore changes in critical loads, also in conjunction with speculative climate-induced increases in NH3 emissions. These calculations suggest that the area of ecosystems that exceeds critical loads is reduced from 64% for year 2005 emissions levels to 50% for currently estimated 2050 levels. A possible climate-induced increase in NH3 emissions could worsen the situation, with areas exceeded increasing again to 57% (for a 30% NH3 emission increase).

  • 48. Siniarovina, U
    et al.
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    High-resolution model simulations of anthropogenic sulphate and sulphur dioxide in Southeast Asia2005In: Atmospheric Environment, ISSN 1352-2310, E-ISSN 1873-2844, Vol. 39, no 11, p. 2021-2034Article in journal (Refereed)
    Abstract [en]

    The Multiple-scale Atmospheric Transport and CHemical modelling system (MATCH)-driven by meteorological data from the ECMWF has been applied to a model domain covering Southeast Asia to complete a simulation extending over the full year of 2000. The current paper presents an evaluation of the model performance using archived chemical and meteorological data collected in the region during the year 2000. The calculated sulphate concentrations (on atmospheric aerosols and in precipitation) compare reasonably with observations while the atmospheric SO(2) mixing ratios show worse correspondence. This latter mismatch is attributed to local variations in the measured SO(2) concentrations that are not resolved in the regional model and possible miss-location of the emissions in our model. It can also be pointed out that different laboratories measuring SO(2) at the same site occasionally report SO(2) concentrations that differs by an order of magnitude or more. The seasonal variations of the modelled species are less than initially expected but generally in accordance with the measurements available. Most of the Malaysian cities have comparatively low concentrations of sulphate in precipitation. This is supported both by the model results and by independent measurements. From the model simulations and the measurements, it is concluded that the sulphur deposition is still relatively low (i.e. < 0.5 g sulphur m(-2) year(-1)) in most of rural Malaysia. This is also the case in Myanmar, Laos, central Vietnam, Kampuchea and southern Thailand. The situation in the vicinity of the large cities in the region is, however, much worse and the deposition is similar, or larger, than estimated critical loads. (c) 2005 Elsevier Ltd. All rights reserved.

  • 49. Wang, Zifa
    et al.
    Xie, Fuying
    Sakurai, T.
    Ueda, H.
    Han, Zhiwei
    Carmichael, G. R.
    Streets, D.
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    Holloway, T.
    Hayami, H.
    Kajino, M.
    Thongboonchoo, N.
    Bennet, Cecilia
    SMHI, Research Department, Air quality.
    Park, S. U.
    Fung, C.
    Chang, A.
    Sartelet, K.
    Amann, M.
    MICS-Asia II: Model inter-comparison and evaluation of acid deposition2008In: Atmospheric Environment, ISSN 1352-2310, E-ISSN 1873-2844, Vol. 42, no 15, p. 3528-3542Article in journal (Refereed)
    Abstract [en]

    This paper focuses on the comparison of chemical deposition of eight regional chemical models used in Model Inter-Comparison Study for Asia (MICS-Asia) II. Monthly-mean depositions of chemical species simulated by these models, including dry deposition of SO(2), HNO(3), NH(3), Sulfate, nitrate and ammonium and wet deposition of SO(4)(2-), NO(3)(-) and NH(4)(+), have been provided for four periods (March, July, December 2001 and March 2002) in this work. Observations at 37 sites of the Acid Deposition Monitoring Network in East Asia (EANET) are compared with SO(4)(2-), NO(3)(-) and NH(4)(+) wet deposition model results. Significant correlations appeared between the observation and computed ensemble mean of participant models. Also, differences among modeled sulfur and nitrogen dry depositions have been studied at the EANET sites. Based on the analysis of acid deposition for various species from different models, total depositions of sulfur (SO(2) and sulfate) and nitrogen (nitrate and ammonium) have been evaluated as the ensemble mean of the eight models. In general, all models capture the observed spatial distribution' of sulfur and nitrogen deposition, although the absolute values may differ from measurements. High deposition often occurs in eastern China, Japan, the Republic of Korea, Thailand, Vietnam, Philippines and other parts of Southeast Asia. The magnitude of model bias is quite large for many of the models. In examining the reasons for model-measurement disagreement, we find that differences in chemical processes, deposition parameterization, and modeled precipitation are the main reasons for large model disparities. (C) 2008 Elsevier Ltd. All rights reserved.

  • 50. Watson, Laura
    et al.
    Lacressonniere, Gwendoline
    Gauss, Michael
    Engardt, Magnuz
    SMHI, Research Department, Air quality.
    Andersson, Camilla
    SMHI, Research Department, Air quality.
    Josse, Beatrice
    Marecal, Virginie
    Nyiri, Agnes
    Sobolowski, Stefan
    Siour, Guillaume
    Szopa, Sophie
    Vautard, Robert
    Impact of emissions and+2 degrees C climate change upon future ozone and nitrogen dioxide over Europe2016In: Atmospheric Environment, ISSN 1352-2310, E-ISSN 1873-2844, Vol. 142, p. 271-285Article in journal (Refereed)
12 1 - 50 of 51
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