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  • 81. Monks, S. A.
    et al.
    Arnold, S. R.
    Emmons, L. K.
    Law, K. S.
    Turquety, S.
    Duncan, B. N.
    Flemming, J.
    Huijnen, V.
    Tilmes, S.
    Langner, Joakim
    SMHI, Forskningsavdelningen, Luftmiljö.
    Mao, J.
    Long, Y.
    Thomas, J. L.
    Steenrod, S. D.
    Raut, J. C.
    Wilson, C.
    Chipperfield, M. P.
    Diskin, G. S.
    Weinheimer, A.
    Schlager, H.
    Ancellet, G.
    Multi-model study of chemical and physical controls on transport of anthropogenic and biomass burning pollution to the Arctic2015Inngår i: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 15, nr 6, s. 3575-3603Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Using observations from aircraft, surface stations and a satellite instrument, we comprehensively evaluate multi-model simulations of carbon monoxide (CO) and ozone (O-3) in the Arctic and over lower latitude emission regions, as part of the POLARCAT Model Inter-comparison Project (POLMIP). Evaluation of 11- atmospheric models with chemistry shows that they generally underestimate CO throughout the Arctic troposphere, with the largest biases found during winter and spring. Negative CO biases are also found throughout the Northern Hemisphere, with multi-model mean gross errors (9-12%) suggesting models perform similarly over Asia, North America and Europe. A multi-model annual mean tropospheric OH (10.8 +/- 0.6 x 10(5) molec cm(-3)) is found to be slightly higher than previous estimates of OH constrained by methyl chloroform, suggesting negative CO biases in models may be improved through better constraints on OH. Models that have lower Arctic OH do not always show a substantial improvement in their negative CO biases, suggesting that Arctic OH is not the dominant factor controlling the Arctic CO burden in these models. In addition to these general biases, models do not capture the magnitude of CO enhancements observed in the Arctic free troposphere in summer, suggesting model errors in the simulation of plumes that are transported from anthropogenic and biomass burning sources at lower latitudes. O-3 in the Arctic is also generally underestimated, particularly at the surface and in the upper troposphere. Summer O-3 comparisons over lower latitudes show several models overestimate upper tropospheric concentrations. Simulated CO, O-3 and OH all demonstrate a substantial degree of inter-model variability. Idealised CO-like tracers are used to quantitatively compare the impact of inter-model differences in transport and OH on CO in the Arctic troposphere. The tracers show that model differences in transport from Europe in winter and from Asia throughout the year are important sources of model variability at Barrow. Unlike transport, inter-model variability in OH similarly affects all regional tracers at Barrow. Comparisons of fixed-lifetime and OH-loss idealised CO-like tracers throughout the Arctic troposphere show that OH differences are a much larger source of inter-model variability than transport differences. Model OH concentrations are correlated with H2O concentrations, suggesting water vapour concentrations are linked to differences in simulated concentrations of CO and OH at high latitudes in these simulations. Despite inter-model differences in transport and OH, the relative contributions from the different source regions (North America, Europe and Asia) and different source types (anthropogenic and biomass burning) are comparable across the models. Fire emissions from the boreal regions in 2008 contribute 33, 43 and 19% to the total Arctic CO-like tracer in spring, summer and autumn, respectively, highlighting the importance of boreal fire emissions in controlling pollutant burdens in the Arctic.

  • 82. Geels, Camilla
    et al.
    Andersson, Camilla
    SMHI, Forskningsavdelningen, Luftmiljö.
    Hanninen, Otto
    Lanso, Anne Sofie
    Schwarze, Per E.
    Skjoth, Carsten Ambelas
    Brandt, Jorgen
    Future Premature Mortality Due to O-3, Secondary Inorganic Aerosols and Primary PM in Europe - Sensitivity to Changes in Climate, Anthropogenic Emissions, Population and Building Stock2015Inngår i: International Journal of Environmental Research and Public Health, ISSN 1661-7827, E-ISSN 1660-4601, Vol. 12, nr 3, s. 2837-2869Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Air pollution is an important environmental factor associated with health impacts in Europe and considerable resources are used to reduce exposure to air pollution through emission reductions. These reductions will have non-linear effects on exposure due, e.g., to interactions between climate and atmospheric chemistry. By using an integrated assessment model, we quantify the effect of changes in climate, emissions and population demography on exposure and health impacts in Europe. The sensitivity to the changes is assessed by investigating the differences between the decades 2000-2009, 2050-2059 and 2080-2089. We focus on the number of premature deaths related to atmospheric ozone, Secondary Inorganic Aerosols and primary PM. For the Nordic region we furthermore include a projection on how population exposure might develop due to changes in building stock with increased energy efficiency. Reductions in emissions cause a large significant decrease in mortality, while climate effects on chemistry and emissions only affects premature mortality by a few percent. Changes in population demography lead to a larger relative increase in chronic mortality than the relative increase in population. Finally, the projected changes in building stock and infiltration rates in the Nordic indicate that this factor may be very important for assessments of population exposure in the future.

  • 83. Mahajan, Anoop S.
    et al.
    Fadnavis, Suvarna
    Thomas, Manu Anna
    SMHI, Forskningsavdelningen, Luftmiljö.
    Pozzoli, Luca
    Gupta, Smrati
    Royer, Sarah-Jeanne
    Saiz-Lopez, Alfonso
    Simo, Rafel
    Quantifying the impacts of an updated global dimethyl sulfide climatology on cloud microphysics and aerosol radiative forcing2015Inngår i: Journal of Geophysical Research - Atmospheres, ISSN 2169-897X, E-ISSN 2169-8996, Vol. 120, nr 6, s. 2524-2536Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    One of the critical parameters in assessing the global impacts of dimethyl sulfide (DMS) on cloud properties and the radiation budget is the estimation of phytoplankton-induced ocean emissions, which are derived from prescribed, climatological surface seawater DMS concentrations. The most widely used global ocean DMS climatology was published 15 years ago and has recently been updated using a much larger database of observations. The updated climatology displays significant differences in terms of the global distribution and regional monthly averages of sea surface DMS. In this study, we use the ECHAM5-HAMMOZ aerosol-chemistry-climate general circulation model to quantify the influence of the updated DMS climatology in computed atmospheric properties, namely, the spatial and temporal distributions of atmospheric DMS concentration, sulfuric acid concentration, sulfate aerosols, number of activated aerosols, cloud droplet number concentration, and the aerosol radiative forcing at the top of the atmosphere. Significant differences are observed for all the modeled variables. Comparison with observations of atmospheric DMS and total sulfate also shows that in places with large DMS emissions, the updated climatology shows a better match with the observations. This highlights the importance of using the updated climatology for projecting future impacts of oceanic DMS emissions, especially considering that the relative importance of the natural sulfur fluxes is likely to increase due to legislation to clean up anthropogenic emissions. The largest estimated differences are in the Southern Ocean, Indian Ocean, and parts of the Pacific Ocean, where the climatologies differ in seasonal concentrations over large geographical areas. The model results also indicate that the former DMS climatology underestimated the effect of DMS on the globally averaged annual aerosol radiative forcing at the top of the atmosphere by about 20%.

  • 84. Burton, S. P.
    et al.
    Hair, J. W.
    Kahnert, Michael
    SMHI, Forskningsavdelningen, Luftmiljö.
    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 Lidar2015Inngår i: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 15, nr 23, s. 13453-13473Artikkel i tidsskrift (Fagfellevurdert)
    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.

  • 85. Colette, Augustin
    et al.
    Andersson, Camilla
    SMHI, Forskningsavdelningen, Luftmiljö.
    Baklanov, Alexander
    Bessagnet, Bertrand
    Brandt, Jorgen
    Christensen, Jesper H.
    Doherty, Ruth
    Engardt, Magnuz
    SMHI, Forskningsavdelningen, Luftmiljö.
    Geels, Camilla
    Giannakopoulos, Christos
    Hedegaard, Gitte B.
    Katragkou, Eleni
    Langner, Joakim
    SMHI, Forskningsavdelningen, Luftmiljö.
    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?2015Inngår i: Environmental Research Letters, ISSN 1748-9326, E-ISSN 1748-9326, Vol. 10, nr 8, artikkel-id 084015Artikkel i tidsskrift (Fagfellevurdert)
    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.

  • 86. Andersson, E.
    et al.
    Kahnert, Michael
    SMHI, Forskningsavdelningen, Luftmiljö.
    Devasthale, Abhay
    SMHI, Forskningsavdelningen, Atmosfärisk fjärranalys.
    Methodology for evaluating lateral boundary conditions in the regional chemical transport model MATCH (v5.5.0) using combined satellite and ground-based observations2015Inngår i: Geoscientific Model Development, ISSN 1991-959X, E-ISSN 1991-9603, Vol. 8, nr 11, s. 3747-3763Artikkel i tidsskrift (Fagfellevurdert)
    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.

  • 87. Marecal, V.
    et al.
    Peuch, V. -H
    Andersson, Camilla
    SMHI, Forskningsavdelningen, Luftmiljö.
    Andersson, S.
    Arteta, J.
    Beekmann, M.
    Benedictow, A.
    Bergström, Robert
    SMHI, Forskningsavdelningen, Luftmiljö.
    Bessagnet, B.
    Cansado, A.
    Cheroux, F.
    Colette, A.
    Coman, A.
    Curier, R. L.
    van der Gon, H. A. C. Denier
    Drouin, A.
    Elbern, H.
    Emili, E.
    Engelen, R. J.
    Eskes, H. J.
    Foret, G.
    Friese, E.
    Gauss, M.
    Giannaros, C.
    Guth, J.
    Joly, M.
    Jaumouille, E.
    Josse, B.
    Kadygrov, N.
    Kaiser, J. W.
    Krajsek, K.
    Kuenen, J.
    Kumar, U.
    Liora, N.
    Lopez, E.
    Malherbe, L.
    Martinez, I.
    Melas, D.
    Meleux, F.
    Menut, L.
    Moinat, P.
    Morales, T.
    Parmentier, J.
    Piacentini, A.
    Plu, M.
    Poupkou, A.
    Queguiner, S.
    Robertson, Lennart
    SMHI, Forskningsavdelningen, Luftmiljö.
    Rouil, L.
    Schaap, M.
    Segers, A.
    Sofiev, M.
    Tarasson, L.
    Thomas, Manu Anna
    SMHI, Forskningsavdelningen, Luftmiljö.
    Timmermans, R.
    Valdebenito, A.
    van Velthoven, P.
    van Versendaal, R.
    Vira, J.
    Ung, A.
    A regional air quality forecasting system over Europe: the MACC-II daily ensemble production2015Inngår i: Geoscientific Model Development, ISSN 1991-959X, E-ISSN 1991-9603, Vol. 8, nr 9, s. 2777-2813Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper describes the pre-operational analysis and forecasting system developed during MACC (Monitoring Atmospheric Composition and Climate) and continued in the MACC-II (Monitoring Atmospheric Composition and Climate: Interim Implementation) European projects to provide air quality services for the European continent. This system is based on seven state-of-the art models developed and run in Europe (CHIMERE, EMEP, EURAD-IM, LOTOS-EUROS, MATCH, MOCAGE and SILAM). These models are used to calculate multi-model ensemble products. The paper gives an overall picture of its status at the end of MACCII (summer 2014) and analyses the performance of the multi-model ensemble. The MACC-II system provides daily 96 h forecasts with hourly outputs of 10 chemical species/aerosols (O-3, NO2, SO2, CO, PM10, PM2.5, NO, NH3, total NMVOCs (non-methane volatile organic compounds) and PAN + PAN precursors) over eight vertical levels from the surface to 5 km height. The hourly analysis at the surface is done a posteriori for the past day using a selection of representative air quality data from European monitoring stations. The performance of the system is assessed daily, weekly and every 3 months (seasonally) through statistical indicators calculated using the available representative air quality data from European monitoring stations. Results for a case study show the ability of the ensemble median to forecast regional ozone pollution events. The seasonal performances of the individual models and of the multi-model ensemble have been monitored since September 2009 for ozone, NO2 and PM10. The statistical indicators for ozone in summer 2014 show that the ensemble median gives on average the best performances compared to the seven models. There is very little degradation of the scores with the forecast day but there is a marked diurnal cycle, similarly to the individual models, that can be related partly to the prescribed diurnal variations of anthropogenic emissions in the models. During summer 2014, the diurnal ozone maximum is underestimated by the ensemble median by about 4 mu g m(-3) on average. Locally, during the studied ozone episodes, the maxima from the ensemble median are often lower than observations by 30-50 mu g m(-3). Overall, ozone scores are generally good with average values for the normalised indicators of 0.14 for the modified normalised mean bias and of 0.30 for the fractional gross error. Tests have also shown that the ensemble median is robust to reduction of ensemble size by one, that is, if predictions are unavailable from one model. Scores are also discussed for PM10 for winter 2013-1014. There is an underestimation of most models leading the ensemble median to a mean bias of 4.5 mu g m(-3). The ensemble median fractional gross error is larger for PM10 (similar to 0.52) than for ozone and the correlation is lower (similar to 0.35 for PM10 and similar to 0.54 for ozone). This is related to a larger spread of the seven model scores for PM10 than for ozone linked to different levels of complexity of aerosol representation in the individual models. In parallel, a scientific analysis of the results of the seven models and of the ensemble is also done over the Mediterranean area because of the specificity of its meteorology and emissions. The system is robust in terms of the production availability. Major efforts have been done in MACC-II towards the operationalisation of all its components. Foreseen developments and research for improving its performances are discussed in the conclusion.

  • 88.
    Kahnert, Michael
    et al.
    SMHI, Forskningsavdelningen, Luftmiljö.
    Rother, Tom
    Electromagnetic Wave Scattering on Nonspherical Particles: Basic Methodology and Simulations2014 (oppl. 2)Bok (Annet vitenskapelig)
  • 89.
    Segersson, David
    SMHI, Forskningsavdelningen, Luftmiljö.
    A dynamic model for shipping emissions: Adaptation of Airviro and application in the Baltic Sea2014Rapport (Annet vitenskapelig)
    Abstract [sv]

    I många länder så är sjöfarten en viktig källa till emissioner av luftföroreningar. Nuförtiden anses sjöfarten ofta vara den viktigaste källan till utsläpp av svavel. Sjöfarten släpper även ut betydande mängder av kväveoxider, partiklar och flyktiga organiska ämnen. Ur klimatperspektiv så är sjöfarten en viktig utsläppakälla för växthusgaser och bidrar även till utsläppen av kortlivade klimatpåverkande ämnen, såsom sot. Utsläpp till luft från sjöfart har påverkan på luftkvalitet, klimatet och försurningen av våra vattendrag.För att förstå vilken påverkan sjöfarten har på miljö, människors hälsa och klimatet, så är det nödvändigt att kvantifiera, kartlägga och beskriva dess emissioner. På grund av avsaknad av data och kunskap så har beräkningar av sjöfartens emissioner alltid varit mycket osäkra. En orsak till osäkerheterna har varit svårigheten att lokalisera och identifiera det stora antal fartyg som rör sig på våra vatten. En annan orsak har varit svårigheter och brist på kunskap kring emissionsfaktorer för fartygsmotorer. Sedan år 2007 har AIS (Automatic Identification System) varit en standard för att positionera och identifiera fartyg till sjöss. AIS är ett komplement till radar och beskriver enskilda fartygs position, fart och identitetmed hög precision. Denna utveckling har öppnat upp nya möjligheter att förbättra information om sjöfartens emissioner.Ett system som använder AIS för att beräkna fartygsemissioner har utvecklats. Systemet möjliggör beräkning av emissioner från fartyg utifrån den senaste kunskapen kring emissionsfaktorer och tar hänsyn till fartygsspecifika uppgifter så långt som möjligt. Drivkraften för denna utveckling är att förbättra kunskapen om sjöfartens påverkan på miljö, människors hälsa och klimatet, samt att erbjuda ett flexibelt verktyg för frågor relaterade till utsläpp av luftföroreningar, växthusgaser och kortlivade klimatpåverkande ämnen. Det utvecklade systemet är en integrerad del i luftvårdssystemet Airviro.Det utvecklade systemet har använts för Östersjön. Denna applikation av systemet kallas för Shipair, vilket avser såväl Airviro som de datakällor som används i denna uppsättning av systemet. Område som täcks in omfattar Östersjön och Nordsjön upp till Norges södra kust. AIS-data hämtas från den databas med alla Östersjöländers AIS information som administreras av HELCOM. Vid sidan av AIS-data använder applikationen Shipair även en webbtjänst från Sjöfarsverket för att inhämta och uppskatta fartygsspecifika uppgifter som behövs för emissionsberäkningarna.Systemet har validerats genom att jämföra beräknad och uppmätt bränsleförbrukning för ett mindre antal fartyg. Jämförelsen visar på god överensstämmelse mellan beräknad och uppmätt bränsleförbrukning, med skillnader under 10 % för individuella fartyg. Jämförelser har även gjorts mot resultat från andra inventeringar av sjöfartens emissioner inom Östersjön. Resultaten överensstämmer väl med publicerade resultat från modellen STEAM2 utförda av FMI (Finska Meteorologiska Institutet). Denna inventering baseras på en liknande metod som Shipair. Större skillnader ses vid en jämförelse med de emissioner som används inom EMEP (Environmental Monitoring and Evaluation Programme), där EMEPs emissioner är betydligt högre än de som beräknas med Shipair. Slutligen genomfördes även indirekt verifiering av resultaten från Shipair genom att jämföra resultat från spridningsmodeller med uppmätta halter i omgivningsluft. På grund av ett stort bidrag från andra källor, vilka döljer signalen från sjöfarten, kunde inga mer detaljerade slutsatser dras rörande resultatens kvalitet. Jämförelsen bekräftade endast att de beräknade emissionerna inte är signifikant överskattade.En jämförelse har även gjorts för att undersöka om emissioner för Svensk inrikes sjöfart beräknade utifrån bränslestatistik är rimliga. Resultaten indikerar att utsläppen från inrikes sjöfart beräknade utifrån bränslestatistik kan vara underskattade med ca 50 %.

  • 90.
    Omstedt, Gunnar
    et al.
    SMHI, Forskningsavdelningen, Luftmiljö.
    Forsberg, Bertil
    Umeå Universitet.
    Persson, Karin
    IVL Svenska Miljöinstitutet.
    Vedrök i Västerbotten - mätningar, beräkningar och hälsokonsekvenser2014Rapport (Annet vitenskapelig)
    Abstract [sv]

    Småskalig vedeldning är en betydande källa till bl a. partiklar, polyaromatiska kolväten (PAH) och sot, föroreningar som påverkar luftkvaliten negativt. Kunskapen är dock begränsad. På uppdrag av Naturvårdsverket har därför detta projekt genomförts, med syfte att förbättra kunskapsläget.Mätningar av vedeldningsrelaterade luftföroreningar har gjorts av IVL i fyra områden med bebyggelse av olika ålder: Vännäs, Vännäsby, Sävar och Taveliden (villaförort i Umeå). En databas för inventerade eldstäder i Västerbotten baserat på information från sotarna har tagits fram av Umeå universitet, som också genomfört frågeundersökning om eldningsvanor. Modellberäkningar av halter och exponering har utförts av SMHI och hälsokonsekvensberäkningar har gjorts av Umeå universitet och SMHI.

  • 91. Kylling, A.
    et al.
    Kahnert, Michael
    SMHI, Forskningsavdelningen, Luftmiljö.
    Lindqvist, H.
    Nousiainen, T.
    Volcanic ash infrared signature: porous non-spherical ash particle shapes compared to homogeneous spherical ash particles2014Inngår i: ATMOSPHERIC MEASUREMENT TECHNIQUES, ISSN 1867-1381, Vol. 7, nr 4, s. 919-929Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The reverse absorption technique is often used to detect volcanic ash clouds from thermal infrared satellite measurements. From these measurements effective particle radius and mass loading may be estimated using radiative transfer modelling. The radiative transfer modelling usually assumes that the ash particles are spherical. We calculated thermal infrared optical properties of highly irregular and porous ash particles and compared these with mass-and volume-equivalent spherical models. Furthermore, brightness temperatures pertinent to satellite observing geometry were calculated for the different ash particle shapes. Non-spherical shapes and volume-equivalent spheres were found to produce a detectable ash signal for larger particle sizes than mass-equivalent spheres. The assumption of mass-equivalent spheres for ash mass loading estimates was found to underestimate mass loading compared to morphologically complex inhomogeneous ash particles. The underestimate increases with the mass loading. For an ash cloud recorded during the Eyjafjallajokull 2010 eruption, the mass-equivalent spheres underestimate the total mass of the ash cloud by approximately 30% compared to the morphologically complex inhomogeneous particles.

  • 92. Kovalets, Ivan V.
    et al.
    Robertson, Lennart
    SMHI, Forskningsavdelningen, Luftmiljö.
    Persson, Christer
    SMHI, Forskningsavdelningen, Luftmiljö.
    Didkivska, Svitlana N.
    Ievdin, Ievgen A.
    Trybushnyi, Dmytro
    Calculation of the far range atmospheric transport of radionuclides after the Fukushima accident with the atmospheric dispersion model MATCH of the JRODOS system2014Inngår i: International Journal of Environment and Pollution, ISSN 0957-4352, E-ISSN 1741-5101, Vol. 54, nr 2-4, s. 101-109Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The paper presents estimates of the far-range atmospheric dispersion of radionuclides after the accident at Fukushima Daiichi Nuclear Power Plant (NPP), obtained using the long-range atmospheric dispersion model MATCH. Software tools were developed to run MATCH in the EU nuclear emergency response system JRODOS using freely available numerical weather prediction (NWP) data of the Global Forecasting System (GFS) operated by the United States National Center of Environmental Prediction (NCEP). Comparisons are made of results with JRODOS/MATCH and a standalone MATCH operated by Swedish Meteorological and Hydrological Institute (SMHI) driven by the European Center for Medium-Range Weather Forecasts (ECMWF) NWP data.

  • 93. Kauhaniemi, M.
    et al.
    Stojiljkovic, A.
    Pirjola, L.
    Karppinen, A.
    Harkonen, J.
    Kupiainen, K.
    Kangas, L.
    Aarnio, M. A.
    Omstedt, Gunnar
    SMHI, Forskningsavdelningen, Luftmiljö.
    Denby, B. R.
    Kukkonen, J.
    Comparison of the predictions of two road dust emission models with the measurements of a mobile van2014Inngår i: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 14, nr 17, s. 9155-9169Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The predictions of two road dust suspension emission models were compared with the on-site mobile measurements of suspension emission factors. Such a quantitative comparison has not previously been reported in the reviewed literature. The models used were the Nordic collaboration model NORTRIP (NOn-exhaust Road TRaffic Induced Particle emissions) and the Swedish-Finnish FORE model (Forecasting Of Road dust Emissions). These models describe particulate matter generated by the wear of road surface due to traction control methods and processes that control the suspension of road dust particles into the air. An experimental measurement campaign was conducted using a mobile laboratory called SNIFFER, along two selected road segments in central Helsinki in 2007 and 2008. The suspended PM10 concentration was measured behind the left rear tyre and the street background PM10 concentration in front of the van. Both models reproduced the measured seasonal variation of suspension emission factors fairly well during both years at both measurement sites. However, both models substantially under-predicted the measured emission values. The article illustrates the challenges in conducting road suspension measurements in densely trafficked urban conditions, and the numerous requirements for input data that are needed for accurately applying road suspension emission models.

  • 94. Maderich, V.
    et al.
    Bezhenar, R.
    Heling, R.
    de With, G.
    Jung, K. T.
    Myoung, J. G.
    Cho, Y-K
    Qiao, F.
    Robertson, Lennart
    SMHI, Forskningsavdelningen, Luftmiljö.
    Regional long-term model of radioactivity dispersion and fate in the Northwestern Pacific and adjacent seas: application to the Fukushima Dai-ichi accident2014Inngår i: Journal of Environmental Radioactivity, ISSN 0265-931X, E-ISSN 1879-1700, Vol. 131, s. 4-18Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The compartment model POSEIDON-R was modified and applied to the Northwestern Pacific and adjacent seas to simulate the transport and fate of radioactivity in the period 1945-2010, and to perform a radiological assessment on the releases of radioactivity due to the Fukushima Dai-ichi accident for the period 2011-2040. The model predicts the dispersion of radioactivity in the water column and in sediments, the transfer of radionuclides throughout the marine food web, and subsequent doses to humans due to the consumption of marine products. A generic predictive dynamic food-chain model is used instead of the biological concentration factor (BCF) approach. The radionuclide uptake model for fish has as a central feature the accumulation of radionuclides in the target tissue. The three layer structure of the water column makes it possible to describe the vertical structure of radioactivity in deep waters. In total 175 compartments cover the Northwestern Pacific, the East China and Yellow Seas and the East/Japan Sea. The model was validated from Cs-137 data for the period 1945-2010. Calculated concentrations of Cs-137 in water, bottom sediments and marine organisms in the coastal compartment, before and after the accident, are in close agreement with measurements from the Japanese agencies. The agreement for water is achieved when an additional continuous flux of 3.6 TBq y(-1) is used for underground leakage of contaminated water from the Fukushima Dai-ichi NPP, during the three years following the accident. The dynamic food web model predicts that due to the delay of the transfer throughout the food web, the concentration of Cs-137 for piscivorous fishes returns to background level only in 2016. For the year 2011, the calculated individual dose rate for Fukushima Prefecture due to consumption of fishery products is 3.6 mu Sv y(-1). Following the Fukushima Dai-ichi accident the collective dose due to ingestion of marine products for Japan increased in 2011 by a factor of 6 in comparison with 2010. (C) 2013 Elsevier Ltd. All rights reserved.

  • 95.
    Thomas, Manu Anna
    et al.
    SMHI, Forskningsavdelningen, Luftmiljö.
    Devasthale, Abhay
    SMHI, Forskningsavdelningen, Atmosfärisk fjärranalys.
    Sensitivity of free tropospheric carbon monoxide to atmospheric weather states and their persistency: an observational assessment over the Nordic countries2014Inngår i: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 14, nr 21, s. 11545-11555Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Among various factors that influence the long-range transport of pollutants in the free troposphere (FT), the prevailing atmospheric weather states probably play the most important role in governing characteristics and efficacy of such transport. The weather states, such as a particular wind pattern, cyclonic or anticyclonic conditions, and their degree of persistency determine the spatio-temporal distribution and the final fate of the pollutants. This is especially true in the case of Nordic countries, where baroclinic disturbances and associated weather fronts primarily regulate local meteorology, in contrast to the lower latitudes where a convective paradigm plays a similarly important role. Furthermore, the long-range transport of pollutants in the FT has significant contribution to the total column burden over the Nordic countries. However, there is insufficient knowledge on the large-scale co-variability of pollutants in the FT and atmospheric weather states based solely on observational data over this region. The present study attempts to quantify and understand this statistical co-variability while providing relevant meteorological background. To that end, we select eight weather states that predominantly occur over the Nordic countries and three periods of their persistency (3 days, 5 days, and 7 days), thus providing in total 24 cases to investigate sensitivity of free tropospheric carbon monoxide, an ideal tracer for studying pollutant transport, to these selected weather states. The eight states include four dominant wind directions (namely, NW, NE, SE and SW), cyclonic and anticyclonic conditions, and the enhanced positive and negative phases of the North Atlantic Oscillation (NAO). For our sensitivity analysis, we use recently released Version 6 retrievals of CO at 500 hPa from the Atmospheric Infrared Sounder (AIRS) onboard Aqua satellite covering the 11-year period from September 2002 through August 2013 and winds from the ECMWF's ERA-Interim project to classify weather states for the same 11-year period. We show that, among the various weather states studied here, southeasterly winds lead to highest observed CO anomalies (up to +8%) over the Nordic countries while transporting pollution from the central and eastern parts of Europe. The second (up to +4%) and third highest (up to +2.5%) CO anomalies are observed when winds are northwesterly (facilitating inter-continental transport from polluted North American regions) and during the enhanced positive phase of the NAO respectively. Higher than normal CO anomalies are observed during anticyclonic conditions (up to +1%) compared to cyclonic conditions. The cleanest conditions are observed when winds are northeasterly and during the enhanced negative phases of the NAO, when relatively clean Arctic air masses are transported over the Nordic regions in the both cases. In the case of nearly all weather states, the CO anomalies consistently continue to increase or decrease as the degree of persistency of a weather state is increased. The results of this sensitivity study further provide an observational basis for the process-oriented evaluation of chemistry transport models, especially with regard to the representation of large-scale coupling of chemistry and local weather states and its role in the long-range transport of pollutants in such models.

  • 96.
    Bergström, Robert
    et al.
    SMHI, Forskningsavdelningen, Luftmiljö.
    Hallquist, M.
    Simpson, D.
    Wildt, J.
    Mentel, T. F.
    Biotic stress: a significant contributor to organic aerosol in Europe?2014Inngår i: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 14, nr 24, s. 13643-13660Artikkel i tidsskrift (Fagfellevurdert)
    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.

  • 97. Simpson, D.
    et al.
    Andersson, Camilla
    SMHI, Forskningsavdelningen, Luftmiljö.
    Christensen, J. H.
    Engardt, Magnuz
    SMHI, Forskningsavdelningen, Luftmiljö.
    Geels, C.
    Nyiri, A.
    Posch, M.
    Soares, J.
    Sofiev, M.
    Wind, P.
    Langner, Joakim
    SMHI, Forskningsavdelningen, Luftmiljö.
    Impacts of climate and emission changes on nitrogen deposition in Europe: a multi-model study2014Inngår i: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 14, nr 13, s. 6995-7017Artikkel i tidsskrift (Fagfellevurdert)
    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).

  • 98.
    Kahnert, Michael
    et al.
    SMHI, Forskningsavdelningen, Luftmiljö.
    Nousiainen, Timo
    Lindqvist, Hannakaisa
    Review: Model particles in atmospheric optics2014Inngår i: Journal of Quantitative Spectroscopy and Radiative Transfer, ISSN 0022-4073, E-ISSN 1879-1352, Vol. 146, s. 41-58Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    This review paper provides an overview over model geometries for computing light scattering by small particles. The emphasis is on atmospheric optics, although much of this review will also be relevant to neighbouring fields, in particular to astronomy. Various morphological particle properties are discussed, such as overall nonsphericity, pristine shapes, aggregation, and different forms of inhomogeneity, e.g. porous and compact inhomogeneous morphologies, as well as encapsulated aggregates. Models employed to reproduce the optical properties of complex particles range from strongly simplified to highly realistic and morphologically sophisticated model geometries. Besides reviewing the most recent literature, we discuss the idea behind models of varying degree of complexity with regard to the intended use of the models. Applications range from fundamental studies of light scattering processes to routine applications of particle optics look-up tables in operational modelling systems. (C) 2014 Elsevier Ltd. All rights reserved.

  • 99. Klingberg, J.
    et al.
    Engardt, Magnuz
    SMHI, Forskningsavdelningen, Luftmiljö.
    Karlsson, P. E.
    Langner, Joakim
    SMHI, Forskningsavdelningen, Luftmiljö.
    Pleijel, H.
    Declining ozone exposure of European vegetation under climate change and reduced precursor emissions2014Inngår i: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 11, nr 19, s. 5269-5283Artikkel i tidsskrift (Fagfellevurdert)
    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.

  • 100.
    Klein, Thomas
    et al.
    SMHI, Samhälle och säkerhet.
    Langner, Joakim
    SMHI, Forskningsavdelningen, Luftmiljö.
    Frankenberg, Britt
    SMHI, Samhälle och säkerhet.
    Svensson, J
    SMHI.
    Broman, Barry
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Bennet, Cecilia
    SMHI, Forskningsavdelningen, Luftmiljö.
    ECDS - a Swedish Research Infrastructure for the Open Sharing of Environment and Climate Data2013Inngår i: Data Science Journal, ISSN 1683-1470, E-ISSN 1683-1470, nr 12, s. 1-9Artikkel i tidsskrift (Fagfellevurdert)
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