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  • 1.
    Andersson, Camilla
    et al.
    SMHI, Research Department, Air quality.
    Andersson, Stefan
    SMHI, Research Department, Air quality.
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Segersson, David
    SMHI, Research Department, Air quality.
    Halter och deposition av luftföroreningar: Förändring över Sverige från 2010 till 2020 i bidrag från Sverige, Europa och Internationell Sjöfart2011Report (Other academic)
    Abstract [sv]

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

  • 2.
    Andersson, Camilla
    et al.
    SMHI, Research Department, Air quality.
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Bergström, Robert
    SMHI, Research Department, Air quality.
    Interannual variation and trends in air pollution over Europe due to climate variability during 1958-2001 simulated with a regional CTM coupled to the ERA40 reanalysis2007In: Tellus. Series B, Chemical and physical meteorology, ISSN 0280-6509, E-ISSN 1600-0889, Vol. 59, no 1, p. 77-98Article in journal (Refereed)
    Abstract [en]

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

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

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

  • 4. Astrom, Christofer
    et al.
    Ebi, Kristie L.
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Forsberg, Bertil
    Developing a Heatwave Early Warning System for Sweden: Evaluating Sensitivity of Different Epidemiological Modelling Approaches to Forecast Temperatures2015In: International Journal of Environmental Research and Public Health, ISSN 1661-7827, E-ISSN 1660-4601, Vol. 12, no 1, p. 254-267Article in journal (Refereed)
    Abstract [en]

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

  • 5. 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.

  • 6. Eckhardt, S.
    et al.
    Quennehen, B.
    Olivie, D. J. L.
    Berntsen, T. K.
    Cherian, R.
    Christensen, J. H.
    Collins, W.
    Crepinsek, S.
    Daskalakis, N.
    Flanner, M.
    Herber, A.
    Heyes, C.
    Hodnebrog, O.
    Huang, L.
    Kanakidou, M.
    Klimont, Z.
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Law, K. S.
    Lund, M. T.
    Mahmood, R.
    Massling, A.
    Myriokefalitakis, S.
    Nielsen, I. E.
    Nojgaard, J. K.
    Quaas, J.
    Quinn, P. K.
    Raut, J. -C
    Rumbold, S. T.
    Schulz, M.
    Sharma, S.
    Skeie, R. B.
    Skov, H.
    Uttal, T.
    von Salzen, K.
    Stohl, A.
    Current model capabilities for simulating black carbon and sulfate concentrations in the Arctic atmosphere: a multi-model evaluation using a comprehensive measurement data set2015In: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 15, no 16, p. 9413-9433Article in journal (Refereed)
    Abstract [en]

    The concentrations of sulfate, black carbon (BC) and other aerosols in the Arctic are characterized by high values in late winter and spring (so-called Arctic Haze) and low values in summer. Models have long been struggling to capture this seasonality and especially the high concentrations associated with Arctic Haze. In this study, we evaluate sulfate and BC concentrations from eleven different models driven with the same emission inventory against a comprehensive pan-Arctic measurement data set over a time period of 2 years (2008-2009). The set of models consisted of one Lagrangian particle dispersion model, four chemistry transport models (CTMs), one atmospheric chemistry-weather forecast model and five chemistry climate models (CCMs), of which two were nudged to meteorological analyses and three were running freely. The measurement data set consisted of surface measurements of equivalent BC (eBC) from five stations (Alert, Barrow, Pallas, Tiksi and Zeppelin), elemental carbon (EC) from Station Nord and Alert and aircraft measurements of refractory BC (rBC) from six different campaigns. We find that the models generally captured the measured eBC or rBC and sulfate concentrations quite well, compared to previous comparisons. However, the aerosol seasonality at the surface is still too weak in most models. Concentrations of eBC and sulfate averaged over three surface sites are underestimated in winter/spring in all but one model (model means for January-March underestimated by 59 and 37% for BC and sulfate, respectively), whereas concentrations in summer are overestimated in the model mean (by 88 and 44% for July-September), but with overestimates as well as underestimates present in individual models. The most pronounced eBC underestimates, not included in the above multi-site average, are found for the station Tiksi in Siberia where the measured annual mean eBC concentration is 3 times higher than the average annual mean for all other stations. This suggests an underestimate of BC sources in Russia in the emission inventory used. Based on the campaign data, biomass burning was identified as another cause of the modeling problems. For sulfate, very large differences were found in the model ensemble, with an apparent anti-correlation between modeled surface concentrations and total atmospheric columns. There is a strong correlation between observed sulfate and eBC concentrations with consistent sulfate/eBC slopes found for all Arctic stations, indicating that the sources contributing to sulfate and BC are similar throughout the Arctic and that the aerosols are internally mixed and undergo similar removal. However, only three models reproduced this finding, whereas sulfate and BC are weakly correlated in the other models. Overall, no class of models (e.g., CTMs, CCMs) performed better than the others and differences are independent of model resolution.

  • 7. Emmons, L. K.
    et al.
    Arnold, S. R.
    Monks, S. A.
    Huijnen, V.
    Tilmes, S.
    Law, K. S.
    Thomas, J. L.
    Raut, J. -C
    Bouarar, I.
    Turquety, S.
    Long, Y.
    Duncan, B.
    Steenrod, S.
    Strode, S.
    Flemming, J.
    Mao, J.
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Thompson, A. M.
    Tarasick, D.
    Apel, E. C.
    Blake, D. R.
    Cohen, R. C.
    Dibb, J.
    Diskin, G. S.
    Fried, A.
    Hall, S. R.
    Huey, L. G.
    Weinheimer, A. J.
    Wisthaler, A.
    Mikoviny, T.
    Nowak, J.
    Peischl, J.
    Roberts, J. M.
    Ryerson, T.
    Warneke, C.
    Helmig, D.
    The POLARCAT Model Intercomparison Project (POLMIP): overview and evaluation with observations2015In: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 15, no 12, p. 6721-6744Article in journal (Refereed)
    Abstract [en]

    A model intercomparison activity was inspired by the large suite of observations of atmospheric composition made during the International Polar Year (2008) in the Arctic. Nine global and two regional chemical transport models participated in this intercomparison and performed simulations for 2008 using a common emissions inventory to assess the differences in model chemistry and transport schemes. This paper summarizes the models and compares their simulations of ozone and its precursors and presents an evaluation of the simulations using a variety of surface, balloon, aircraft and satellite observations. Each type of measurement has some limitations in spatial or temporal coverage or in composition, but together they assist in quantifying the limitations of the models in the Arctic and surrounding regions. Despite using the same emissions, large differences are seen among the models. The cloud fields and photolysis rates are shown to vary greatly among the models, indicating one source of the differences in the simulated chemical species. The largest differences among models, and between models and observations, are in NOy partitioning (PAN vs. HNO3) and in oxygenated volatile organic compounds (VOCs) such as acetaldehyde and acetone. Comparisons to surface site measurements of ethane and propane indicate that the emissions of these species are significantly underestimated. Satellite observations of NO2 from the OMI (Ozone Monitoring Instrument) have been used to evaluate the models over source regions, indicating anthropogenic emissions are underestimated in East Asia, but fire emissions are generally overestimated. The emission factors for wildfires in Canada are evaluated using the correlations of VOCs to CO in the model output in comparison to enhancement factors derived from aircraft observations, showing reasonable agreement for methanol and acetaldehyde but underestimate ethanol, propane and acetone, while overestimating ethane emission factors.

  • 8.
    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.

  • 9. Gallardo, L
    et al.
    Olivares, G
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Aarhus Andrae, Bodil
    SMHI, Core Services.
    Coastal lows and sulfur air pollution in Central Chile2002In: Atmospheric Environment, ISSN 1352-2310, E-ISSN 1873-2844, Vol. 36, no 23, p. 3829-3841Article in journal (Refereed)
    Abstract [en]

    Air pollutants in Santiago (33.5degreesS, 70.8degreesW, 500m a.s.l.), a city with 5 million inhabitants, located in a basin in Central Chile surrounded by the high Andes, frequently exceed air quality standards. This affects human health and it stresses vegetation. The most extreme winter and fall pollution events occur when the subsident regime of the Pacific high is further enhanced by coastal lows (CLs), which bring down the base of the subsidence inversion. Under these conditions, the air quality worsens significantly giving rise to acute air pollution episodes. We assess the ability of a regional transport/chemistry/deposition model (MATCH) coupled to a meteorological model (High Resolution Limited Area Model-HIRLAM) to simulate the evolution of oxidized sulfur (SOx) in connection with intensive CLs. We focus on SOx since it is an environmental issue of concern, and the emissions and concentrations of SOx have been regularly monitored making it easier to bracket model outputs for SOx than for other pollutants. Furthermore, the SOx emissions in the area are very large, i.e., about 0.4% of the global anthropogenic sources. Comparisons with observations indicate that the combination of HIRLAM and MATCH is a suitable tool for describing the regional patterns of dispersion associated with CLs. However, the low number and the limited geographical coverage of reliable air quality data preclude a complete evaluation of the model. Nevertheless, we show evidence of an enhanced contribution of the largest copper smelter in the area, i.e., Caletones, to the burden of SOx in the Santiago basin, especially in the form of sulfate associated to fine particles (diameters < 2.5 mum), during CLs. Further, we speculate that the Caletones plume may trigger or promote secondary aerosol formation during CLs in the Santiago basin. (C) 2002 Elsevier Science Ltd. All rights reserved.

  • 10.
    Gidhagen, Lars
    et al.
    SMHI, Research Department, Air quality.
    Johansson, C
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Foltescu, Valter
    SMHI.
    Urban scale modeling of particle number concentration in Stockholm2005In: Atmospheric Environment, ISSN 1352-2310, E-ISSN 1873-2844, Vol. 39, no 9, p. 1711-1725Article in journal (Refereed)
    Abstract [en]

    A three-dimensional dispersion model has been implemented over the urban area of Stockholm (35 x 35 km) to assess the spatial distribution of number concentrations of particles in the diameter range 3-400 nm. Typical number concentrations in the urban background of Stockholm is 10 000 cm(-3), while they are three times higher close to a major highway outside the city and seven times higher within a densely trafficked street canyon site in the city center. The model, which includes an aerosol module for calculating the particle number losses due to coagulation and dry deposition, has been run for a 10-day period. Model results compare well with measured data, both in levels and in temporal variability. Coagulation was found to be of little importance in terms of time averaged concentrations, contributing to losses of only a few percent as compared to inert particles, while dry deposition yield particle number losses of up to 25% in certain locations. Episodic losses of up to 10% due to coagulation and 50% due to deposition, are found some kilometers downwind of major roads, rising in connection with low wind speed and suppressed turbulent mixing. Removal due to coagulation and deposition will thus be more significant for the simulation of extreme particle number concentrations during peak episodes. The study shows that dispersion models with proper aerosol dynamics included may be used to assess particle number concentrations in Stockholm, where ultrafine particles principally originate from traffic emissions. Emission factors may be determined from roadside measurements, but ambient temperature must be considered, as it has a strong influence on particle number emissions from vehicles. (c) 2005 Elsevier Ltd. All rights reserved.

  • 11.
    Gidhagen, Lars
    et al.
    SMHI, Research Department, Air quality.
    Johansson, C
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Olivares, G
    Simulation of NOx and ultrafine particles in a street canyon in Stockholm, Sweden2004In: Atmospheric Environment, ISSN 1352-2310, E-ISSN 1873-2844, Vol. 38, no 14, p. 2029-2044Article in journal (Refereed)
    Abstract [en]

    A computational fluid dynamic (CFD) model has been used to assess the concentrations of NO, and particle number in a street canyon in Stockholm with a high traffic volume. Comparisons of a simulated 11-week long time series of NOx with measurements (both sides of the street, urban background excluded) show good agreement, especially if emissions are distributed to be three times higher along the side of the street where the traffic is uphill, as compared to the downhill side. The simulation of number concentrations of inert particles indicates a similar asymmetry in emissions. A month-long measurement of particle size distribution (7-450 nm) at street level indicates that the ratio of nucleation size mode particle (7-20 nm) to total particle number (7-450 nm) is decreasing for increased particle surface area. Given the strong dominance of the locally generated particles over the urban background, this is interpreted as a local change in the size distribution. The results of a monodisperse aerosol dynamic model, coupled to the CFD model that simulates also the turbulence generated by vehicle movements, show that coagulation and deposition may reduce total particle inside the canyon with approximately 30% during low wind speeds. Most of the removal occurs shortly after emission, before the particles reach the leeward curb-side. Losses between the leeward curb-side and other locations in the street, e.g. roof levels, is estimated to be smaller, less than 10%. Coagulation is the dominating removal process under low wind speed conditions and deposition for higher wind speeds, the summed removal being smaller for high wind velocities. Deposition is enhanced over the road surface due to the velocities generated by vehicle movements. Although coagulation and deposition removal is most effective on the smallest ultrafine particles, this effect is not sufficient to explain the observed change in size distribution. It is suggested that also the formation of particles in the exhaust plumes is influenced by a larger particle surface area in the ambient air. (C) 2004 Elsevier Ltd. All rights reserved.

  • 12.
    Gidhagen, Lars
    et al.
    SMHI, Research Department, Air quality.
    Johansson, C
    Omstedt, Gunnar
    SMHI, Research Department, Air quality.
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Olivares, G
    Model simulations of NOx and ultrafine particles close to a Swedish highway2004In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 38, no 24, p. 6730-6740Article in journal (Refereed)
    Abstract [en]

    Based on the results from a 6-week monitoring campaign in an area close to a major highway north of Stockholm, Sweden, NOx emission factors representative for vehicle speeds of 100-120 km per h were determined to 0.61 g/veh-km for light duty and to 7.1 g/veh,km for heavy duty vehicles. The corresponding factors for particle number were 1.4 x 10(14) and 52 x 10(14) particles/veh,km, determined for an ambient temperature interval of +7 to +17 degreesC. The removal effects of coagulation and dry deposition on total number concentrations were assessed by numerical model simulations. Velocity and turbulence fields, including those produced by the vehicles, were simulated in a Computational Fluid Dynamics (CFD) model. Coagulation was found to be of little importance over the first 100 m downwind of the highway. The high friction velocities over the road surface created by vehicle movements enhanced deposition locally, contributing to the removal of approximately 10% of the particles originally emitted. Beyond a point 10 m downwind of the highway the removal rate was low and the ultrafine particles were almost inert while being advected over the next hundred meters. As a consequence, it seems reasonable to use monitored data from stations close to highways to estimate emission factors for particle number, assuming that the particles are inert. Those "effective" emission factors should be applicable for urban models with a larger spatial resolution.

  • 13. 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)
  • 14.
    Klein, Thomas
    et al.
    SMHI, Core Services.
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Frankenberg, Britt
    SMHI, Core Services.
    Svensson, J
    SMHI.
    Broman, Barry
    SMHI, Research Department, Climate research - Rossby Centre.
    Bennet, Cecilia
    SMHI, Research Department, Air quality.
    ECDS - a Swedish Research Infrastructure for the Open Sharing of Environment and Climate Data2013In: Data Science Journal, ISSN 1683-1470, E-ISSN 1683-1470, no 12, p. 1-9Article in journal (Refereed)
  • 15. 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.

  • 16.
    Langner, Joakim
    et al.
    SMHI, Research Department, Air quality.
    Alpfjord Wylde, Helene
    SMHI, Professional Services.
    Andersson, Camilla
    SMHI, Research Department, Air quality.
    Mapping of phytotoxic ozone dose for birch, spruce, wheat and potato using the MATCH-Sweden system2019Report (Other academic)
    Abstract [en]

    We have added calculations of PODY for birch, spruce, wheat and potato to theMATCH-Sweden system. Several important updates compared to the previousimplementation for generic crops and generic deciduous trees have been made includingimproved calculations of canopy level ozone concentrations, updated calculations ofquasi-laminar and surface resistance and inclusion of soil moisture dependence forspecific vegetation species. 

    A comparison to results from the EMEP model for generic crops and generic deciduoustrees shows a better agreement than previously. Considering also that an error in theEMEP calculations has been identified, affecting primarily the PODY calculations forgeneric deciduous trees, MATCH-Sweden and EMEP model results now appear to bemore consistent.Year to year variability of PODY for birch and spruce are similar to that for genericdeciduous trees while numerical values are different, especially for birch, due to differentparameters in the PODY calculation and longer vegetation periods. Critical levelscorresponding to a 4 % growth reduction are exceeded for both birch and spruce in majorparts of Sweden for all years in the period 2013-2017.Year to year variability of PODY for wheat and potato are larger than for generic cropsdue to the higher threshold for PODY used in the calculations. Critical levelscorresponding to a 5 % reduction in crop yield are reached in four of five years insouthern Sweden for wheat and for two in five years for potato.The updated program package for PODY calculations could be used to calculateconsistent time series of PODY for different types of vegetation for the period 1990-2013based on reanalyzed ozone concentrations. The program package could also be developedto calculate PODY for the whole of Europe for different emission- or climate scenarios.The results presented in this report are also available in digital form at the SMHI homepage for environmental monitoring of air quality(www.smhi.se/klimatdata/miljo/atmosfarskemi).

  • 17.
    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.

  • 18.
    Langner, Joakim
    et al.
    SMHI, Research Department, Air quality.
    Bergström, Robert
    SMHI, Research Department, Air quality.
    Impact of Climate Change on Regional Air Pollution Budgets2001In: Transport and Chemical Transformation in the Troposphere - Proceedings of EUROTRAC Symposium 2000 Garmisch-Partenkirchen, Germany 27-31 March 2000 / [ed] Midgley, P.M., Reuther, M. and Williams, M., Springer Berlin/Heidelberg, 2001Chapter in book (Other academic)
  • 19.
    Langner, Joakim
    et al.
    SMHI, Research Department, Air quality.
    Bergström, Robert
    SMHI, Research Department, Air quality.
    Foltescu, Valentin
    SMHI.
    Impact of climate change on surface ozone and deposition of sulphur and nitrogen in Europe2005In: Atmospheric Environment, ISSN 1352-2310, E-ISSN 1873-2844, Vol. 39, no 6, p. 1129-1141Article in journal (Refereed)
    Abstract [en]

    The potential impact of regional climate change on the distribution and deposition of air pollutants in Europe has been studied using a regional chemistry/transport/deposition model, MATCH. MATCH was set up using meteorological output from two 10-year climate change experiments made with the Rossby Centre regional Atmospheric climate model version 1 (RCA1). RCA1 was forced by boundary conditions from two different global climate models using the IPCC IS92a (business as usual) emission scenario. The global mean warming in both the GCMs was 2.6 K and was reached in the period 2050-2070. Simulations with MATCH indicate substantial potential impact of regional climate change on both deposition of oxidised nitrogen and concentrations of surface ozone. The simulations show a strong increase in surface ozone expressed as AOT40 and mean of daily maximum over southern and central Europe and a decrease in northern Europe. The simulated changes in April September AOT40 are significant in relation to inter-annual variability over extended areas. Changes in deposition of oxidised nitrogen are much smaller and also less coherent due to the strong inter-annual variability in precipitation in the RCA1 simulations and differences in the regional climate change simulated with RCA1 in the two regional scenarios. Changes in simulated annual deposition are significant in relation to inter-annual variability only over small areas. This indicates that longer simulation periods are necessary to establish changes in deposition. (C) 2004 Elsevier Ltd. All rights reserved.

  • 20.
    Langner, Joakim
    et al.
    SMHI, Research Department, Air quality.
    Bergström, Robert
    SMHI, Research Department, Air quality.
    Klein, Thomas
    SMHI, Core Services.
    Skagerström, M.
    SMHI.
    Nuläge och scenarier för inverkan på marknära ozon av emissioner från Västra Götalands län - Beräkningar för 19992004Report (Other academic)
    Abstract [sv]

    SMHI har på uppdrag av Länsstyrelsen i Västra Götalands län studerat hur olikascenarier för reducerade NOx och VOC-utsläpp från Västra Götaland påverkarfördelningen av marknära ozon över södra Sverige. Studien har utnyttjat den atmosfärkemiskaspridningsmodellen MATCH (Multi-scale Atmospheric Transportand Chemistry model). Modellen har först applicerats över hela Europa förår 1999 med aktuella emissioner. Resultaten från dessa beräkningar har sedankopplats till en högupplöst modell, MATCH-O-län, som täcker södra Sverige.Beräkningar med MATCH har genomförts för ett nuläge (basfall) med utsläppsdataför år 2000/2001 och tre scenarier där utsläppen har reducerats. Scenariermed reduktion av NOx och VOC-utsläppen från Västra Götalands län med 45 respektive44% var för sig respektive sammantaget har studerats. För basfallet harjämförelser gjorts med mätningar av marknära ozon i området för år 1999. Medutgångspunkt från dessa jämförelser bedömer vi att MATCH ger en tillräckligtgod beskrivning av de verkliga ozonhalterna för att kunna utnyttjas för studier avscenarier.Beräkningarna visar att utsläppen från Västra Götaland har en signifikant påverkanpå halterna av marknära ozon i södra Sverige. Reducerade utsläpp leder generellttill reducerade halter av marknära ozon i södra Sverige och lägre värdenför olika mått på kritiska nivåer av halten av marknära ozon. Effekterna av reduceradeutsläpp berör inte bara närområdet utan täcker ett område som är fleragånger större än det område där utsläppen har ändrats.I området närmast Göteborg leder emellertid reducerade NOx-utsläpp till ökadehalter av ozon. Denna effekt är mindre vid en samtidig reduktion av NOx ochVOC.Bortsett från området med stora NOx-utsläpp i västra delen av Västra Götalandså är reduktioner av NOx effektivare när det gäller att reducera halterna av marknäraozon än reduktion av VOC-utsläpp. Reduktion av NOx-utsläpp är mer änsju gånger effektivare än reduktion av VOC-utsläpp när det gäller att reducerabildningen av ozon inom modellområdet för MATCH-O-län under periodenapril-september 1999.Reducerade utsläpp av NOx och VOC från Västra Götaland beräknas, i större delenav länet, leda till en viss minskning av antalet dagar med 8-timmars medelhaltersom överskrider 120 μg/m3 (60 ppb(v)) under sommarperioden aprilseptember.Reducerad NOx-utsläpp förväntas dock leda till ett ökat antal dagarmed överskridanden i Göteborgsområdet.Reducerade utsläpp från Västra Götaland leder till en reduktion av AOT401 med0.1 ppm(v) h över en stor del av södra Sverige under perioden maj-juli. Den2maximala reduktionen överstiger 0.5 ppm(v) i enstaka beräkningsrutor. För periodenapril-september reduceras AOT40 med mer än 0.1 ppm(v) h i en större delav södra Sverige och en reduktion med mer än 0.5 ppm(v) h beräknas för en stordel av Västra Götaland.

  • 21.
    Langner, Joakim
    et al.
    SMHI, Research Department, Air quality.
    Bergström, Robert
    SMHI, Research Department, Air quality.
    Plejel, Karin
    Swedish Environmental Research Institute IVL.
    European scale modeling of sulfur, oxidized nitrogen and photochemial oxidants: Model development and evaluation for the 1994 growing season1998Report (Other academic)
    Abstract [en]

    A chemical mechanism, including the relevant reactions leading to the production of ozone and other photochemical oxidants, has been implemented in the MATCH regional tracer transport/chemistry/deposition model. The aim has been to develop a model platform that can be used as a basis for a range of regional scale studies involving atmospheric chemistry, including assessment of the importance of different sources of pollutants to the levels of photochemical oxidants and air pollutant forecasting. Meteorological input data to the model were taken from archived output from the operational version of HIRLAM at SMHI. Evaluation of model calculations over Europe for a six month period in 1994 for a range of chemical components show good results considering known sources of error and uncertainties in input data and model formulation. With limited further work the system is sufficiently good to be applied for scenario studies and for regional scale air pollutant forecasts.

  • 22.
    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.

  • 23.
    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.

  • 24.
    Langner, Joakim
    et al.
    SMHI, Research Department, Air quality.
    Persson, Christer
    SMHI, Research Department, Air quality.
    Robertson, Lennart
    SMHI, Research Department, Air quality.
    Concentration and deposition of acidifying air pollutants over Sweden: Estimates for 1991 based on the match model and observations1995In: Water, Air and Soil Pollution, ISSN 0049-6979, E-ISSN 1573-2932, Vol. 85, no 4, p. 2021-2026Article in journal (Refereed)
    Abstract [en]

    The MATCH (Mesoscale Atmospheric Transport and CHemistry) model has been developed as a tool for air pollution assessment studies on different geographical scales. MATCH is an Eulerian atmospheric dispersion model, including physical and chemical processes governing sources, atmospheric transport and sinks of oxidized sulfur and oxidized and reduced nitrogen. Using a combination of air and precipitation chemistry measurements and the MATCH model, the national and long-range transport contributions to air pollution and deposition can be quantified in the model region. The calculations for the year 1991 show that the Swedish import was about 4.5 times larger than the export for sulfur and about six times larger for reduced nitrogen, while the Swedish import of oxidized nitrogen only exceeded the export by 10%. Using the MATCH system we estimate the long-range transport in an independent way compared to EMEP. Comparison between the EMEP and MATCH calculations for 1991 show that the total deposition of oxidized nitrogen over Sweden is similar, while the EMEP-values for total deposition of oxidized sulfur and reduced nitrogen are 25% respectively 40% smaller than what is obtained from MATCH.

  • 25.
    Langner, Joakim
    et al.
    SMHI, Research Department, Air quality.
    Persson, Christer
    SMHI, Research Department, Air quality.
    Robertson, Lennart
    SMHI, Research Department, Air quality.
    Ullerstig, Anders
    SMHI, Research Department, Climate research - Rossby Centre.
    Air pollution Assessment Study Using the MATCH Modelling System: Application to sulfur and nitrogen compounds over Sweden 19941996Report (Other academic)
  • 26.
    Langner, Joakim
    et al.
    SMHI, Research Department, Air quality.
    Robertson, Lennart
    SMHI, Research Department, Air quality.
    Persson, Christer
    SMHI, Research Department, Air quality.
    Ullerstig, Anders
    SMHI, Research Department, Climate research - Rossby Centre.
    Validation of the operational emergency response model at the Swedish Meteorological and Hydrological Institute using data from ETEX and the Chernobyl accident1998In: Atmospheric Environment, ISSN 1352-2310, E-ISSN 1873-2844, Vol. 32, no 24, p. 4325-4333Article in journal (Refereed)
    Abstract [en]

    The Eulerian atmospheric tracer transport model MATCH (Multiscale Atmospheric Transport and Chemistry model) has been extended with a Lagrangian particle model treating the initial dispersion of pollutants from point sources. The model has been implemented at the Swedish Meteorological and Hydrological Institute in an emergency response system for nuclear accidents and can be activated on short notice to provide forecast concentration and deposition fields. The model has been used to simulate the transport of the inert tracer released during the ETEX experiment and the transport and deposition of Cs-137 from the Chernobyl accident. Visual inspection of the results as well as statistical analysis shows that the extent, time of arrival and duration of the tracer cloud, is in good agreement with the observations for both cases, with a tendency towards over-prediction for the first ETEX release. For the Chernobyl case the simulated deposition pattern over Scandinavia and over Europe as a whole agrees with observations when observed precipitation is used in the simulation. When model calculated precipitation is used, the quality of the simulation is reduced significantly and the model fails to predict major features of the observed deposition held. (C) 1998 Elsevier Science Ltd. All rights reserved.

  • 27.
    Langner, Joakim
    et al.
    SMHI, Research Department, Air quality.
    RODHE, H
    CRUTZEN, PJ
    ZIMMERMANN, P
    ANTHROPOGENIC INFLUENCE ON THE DISTRIBUTION OF TROPOSPHERIC SULFATE AEROSOL1992In: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 359, no 6397, p. 712-716Article in journal (Refereed)
    Abstract [en]

    HUMAN activities have increased global emissions of sulphur gases by about a factor of three during the past century, leading to increased sulphate aerosol concentrations, mainly in the Northern Hemisphere. Sulphate aerosols can affect the climate directly, by increasing the backscattering of solar radiation in cloud-free air, and indirectly, by providing additional cloud condensation nuclei1-4. Here we use a global transport-chemistry model to estimate the changes in the distribution of tropospheric sulphate aerosol and deposition of non-seasalt sulphur that have occurred since pre-industrial times. The increase in sulphate aerosol concentration is small over the Southern Hemisphere oceans, but reaches a factor of 100 over northern Europe in winter. Our calculations indicate, however, that at most 6% of the anthropogenic sulphur emissions is available for the formation of new aerosol particles. This is because about one-half of the sulphur dioxide is deposited on the Earth's surface, and most of the remainder is oxidized in cloud droplets so that the sulphate becomes associated with pre-existing particles. Even so, the rate of formation of new sulphate particles may have doubled since pre-industrial times.

  • 28.
    Leung, Wing
    et al.
    SMHI, Professional Services.
    Windmark, Fredrik
    SMHI, Professional Services.
    Brodl, Ludvik
    SMHI, Professional Services.
    Langner, Joakim
    SMHI, Research Department, Air quality.
    A basis to estimate marginal cost for air traffic in Sweden.: Modelling of ozone, primary and secondary particles and deposition of sulfur and nitrogen.2018Report (Other academic)
    Abstract [en]

    In this study we have investigated the effects of emissions from aviation on air quality in both Swedish and European domains. The results will be used as a basis to estimate the marginal cost for air traffic in Sweden. The vertical, geographical and temporal distribution of aviation emissions over Sweden has been estimated using a newly developed methodology. The aviation emissions have been categorized by their emission altitude (LTO, low cruise and high cruise) and flight nationality (international, national and overflight). This aviation emission information was then used as input data to the regional atmospheric chemistry model MATCH to simulate the effects of aviation emissions on ecosystem, health and climate metrics. A total of 17 model simulations over three years have been performed. There is one simulation in which all emitted species from the surface and aviation emissions are included and eight simulations in which all aviation emissions from each combination of emission altitude and flight nationality are included. There are eight simulations in which NOx aviation emissions from each combination of emission altitude and flight nationality are included. Using these simulations, contributions from aviation emissions to deposition, concentrations and a range of different air pollution metrics has been calculated. The results are calculated in both the Europe and Swedish domains for all the simulations. 

    The following results are included in this report: . Deposition of oxidised and reduced nitrogen . Deposition of excess sulfur . AOT40 and SOMO35 and their exposures . Concentration and exposure of primary and secondary particles . Concentration of nitrate and sulfate particles . Concentration of surface and above surface ozone 

    In summary, contributions from aviation emissions in Sweden to the different concentrations, deposition and metrics for environmental effects are generally small, on the order of a few per mille or less. However the impacts can be traced in the simulations well beyond the Swedish borders. LTO emissions give the largest contribution to deposition of oxidised and reduced nitrogen, deposition of excess sulfur and concentrations of primary and secondary particles. In particular near the major airports like Stockholm-Arlanda and Gothenburg-Landvetter. High cruise emissions give insignificant contributions to deposition and concentrations at surface level. LTO emissions give a negative contribution to surface ozone concentration locally at the main Swedish airports but give an overall increased contribution in the regions around. Aviation emissions at low cruise and high cruise levels have the largest effect on ozone concentrations at higher levels. 

  • 29. Lewinschal, Anna
    et al.
    Ekman, Annica M. L.
    Hansson, Hans-Christen
    Sand, Maria
    Berntsen, Terje K.
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Local and remote temperature response of regional SO2 emissions2019In: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 19, no 4, p. 2385-2403Article in journal (Refereed)
  • 30. Mahmood, Rashed
    et al.
    von Salzen, Knut
    Flanner, Mark
    Sand, Maria
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Wang, Hailong
    Huang, Lin
    Seasonality of global and Arctic black carbon processes in the Arctic Monitoring and Assessment Programme models2016In: Journal of Geophysical Research - Atmospheres, ISSN 2169-897X, E-ISSN 2169-8996, Vol. 121, no 12, p. 7100-7116Article in journal (Refereed)
  • 31.
    Marmefelt, Eleonor
    et al.
    SMHI, Professional Services.
    Arheimer, Berit
    SMHI, Research Department, Hydrology.
    Langner, Joakim
    SMHI, Research Department, Air quality.
    An integrated biogeochemical model system for the Baltic Sea1999In: Hydrobiologia, ISSN 0018-8158, E-ISSN 1573-5117, Vol. 393, p. 45-56Article in journal (Refereed)
    Abstract [en]

    The Swedish Meteorological and Hydrological Institute (SMHI) is developing an integrated biogeochemical model system for the Baltic Sea. It consists of three coupled models; a marine biogeochemical-hydrodynamical model (SCOBI), a continuous riverine nitrogen transport model (HBV-N) and an atmospheric transport and chemical model (MATCH). It is supplied with a tool for presentation and analysis. The SCOBI model is a coupled one-dimensional model with high vertical resolution. Horizontal variations are taken into account by dividing the area into smaller boxes. The model includes primary phytoplankton production, nitrogen fixation and secondary zooplankton production. Nitrogen load from land is obtained through the HBV-N model, which simulates organic and inorganic nitrogen separately in catchments. The model is based on the hydrological model HBV, and the subbasin runoff is simulated on a daily basis. The HBV-N model is calibrated and validated against measured concentrations and water flow in rivers. The atmospheric input of oxidised and reduced nitrogen is taken from the annual assessments carried out with the MATCH-Sweden modelling system. MATCH-Sweden combines model calculations, using an atmospheric transport and chemical model, with observations of air- and precipitation chemistry data to give a detailed mapping of concentrations and deposition of nitrogen compounds over Sweden. Supplemented with monitoring data for the specific area of interest, the integrated biogeochemical model system makes a useful tool for environmental protection analyses; e.g. for interpretation of monitoring data as well as creating scenarios for studies of effects in changes of the nutrient loads.

  • 32. 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, Research Department, Air quality.
    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 Arctic2015In: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 15, no 6, p. 3575-3603Article in journal (Refereed)
    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.

  • 33. Olivares, G
    et al.
    Gallardo, L
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Aarhus Andrae, Bodil
    SMHI, Core Services.
    Regional dispersion of oxidized sulfur in Central Chile2002In: Atmospheric Environment, ISSN 1352-2310, E-ISSN 1873-2844, Vol. 36, no 23, p. 3819-3828Article in journal (Refereed)
    Abstract [en]

    Chile has a long tradition of exploiting mineral resources, particularly copper (Cu). One of the largest Cu smelters, Caletones, located some 150 km south of the country's capital, Santiago, in Central Chile, is responsible for about 0.4% of about 70 Tg S/yr oxidized sulfur (SOx) emitted by anthropogenic sources worldwide. Santiago, a megacity with 5 million inhabitants, stands for about 5 Gg S/yr. The average meteorological conditions are unfavorable for the dispersion of pollutants in this area. All this poses risks for human health and vegetation. Also, downwind. from these polluted areas there may be large-scale impacts on cloud properties and on oxidative cycles. Here, we present the first attempt to assess the regional distribution of SOx in Central Chile using a dispersion model (MATCH) driven with data from a limited area weather forecast model (HIRLAM). Emphasis has been given to the impact of Cu smelters upon urban air quality, particularly that of Santiago. Six 1-month long periods were simulated for the years 1997, 1998 and 1999. These periods span over a broad range of typical meteorological conditions in the area including El Nino and La Nina years. Estimates of the regional dispersion and deposition patterns were calculated. The emissions from the large Cu smelters dominate the distribution of SOx. A budget of SOx over an area of 200 x 200 km 2 around Santiago is presented. There is too low a number of monitoring stations to perform a detailed evaluation of MATCH. Nevertheless, the model reproduces consistently all the regional-scale characteristics that can be derived from the available observations. (C) 2002 Published by Elsevier Science Ltd.

  • 34.
    Omstedt, Gunnar
    et al.
    SMHI, Research Department, Air quality.
    Gidhagen, Lars
    SMHI, Research Department, Air quality.
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Spridning av förbränningsemissioner från småskalig biobränsleeldning - analys av PM2.5 data från Lycksele med hjälp av två Gaussiska spridningsmodeller2002Report (Other academic)
    Abstract [sv]

    Under ca 3 månader vintern 2001/2002 utfördes mätningar av luftkvalitet och meteorologi i Lycksele. En emissionsdatabas (EDB Tot03) för Lycksele har tidigare tagits fram (SLBanalys, 2002). Dessa data utgör grundkomponenter för den spridningsmodellering som här redovisas. Redovisningen begränsas till emissioner av förbränningspartiklar och två lokala spridningsmodeller. Arbetet har utförts med stöd från Energimyndigheten (Projektnummer: P12658-1) och ingår som en del i "Omgivningsklustret" i projektet "Biobränsle Hälsa och Miljö". Detaljerade studier görs i Lycksele och Växjö. Denna rapport redovisar resultat från den spridningsmeteorologiska utvärderingen av mätkampanjen i Lycksele. Arbetet syftar till att utveckla verktyg för kommunal och regional planering, vad avser luftkvalitetsaspekter av biobränsleanvändning.Resultaten av denna undersökning kan sammanfattas på följande sätt: Signifikanta lokala haltbidrag, av förbränningspartiklar från vedeldning, uppmättes huvudsakligen under kalla dagar, då dygnmedeltemperaturen var under –10 grader. Antalet sådana dagar var knappt 30. Modellerna beskriver relativt väl dessa halter. Avvikelsen är störst vid Norrmalm. Under övrig tid var de lokala haltbidragen små. PM2.5 halterna var då i genomsnitt bara ca 2 g/m3 högre än bakgrundshalterna, uppmätta vid Vindeln. Modellerna överskattar då halterna, troligtvis beroende på för höga emissioner orsakat av för hög eldningsaktivitet. Det finns ett starkt samband mellan halter och temperatur. Temperaturberoende korrektionsfunktioner har tagits fram för att beskriva eldningsaktiviteten under mätperioden. Modellerna överensstämmer relativt väl med alla mätdata då eldningsaktiviteten beskrivs med hjälp av dessa funktioner. Emissionsdatabasen (EDB Tot03) överskattar därför troligtvis emissionerna av förbränningspartiklar från småskalig vedeldning. Analysen i denna rapport uppskattar emissionerna under beräkningsperioden till ca 30-50% jämfört med de i emissionsdatabasen. De högsta haltbidragen av förbränningspartiklar från vedeldning i Lycksele inträffar nära utsläppen, inom några 100 meters avstånd från främst närliggande samverkande icke miljögodkända pannor. Kaminernas betydelse för förhöjda halter är osäkra, vilket kommer att utredas i mer detalj när nya emissionsfaktorer erhållits.

  • 35. Orru, Hans
    et al.
    Andersson, Camilla
    SMHI, Research Department, Air quality.
    Ebi, Kristie L.
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Astrom, Christofer
    Forsberg, Bertil
    Impact of climate change on ozone-related mortality and morbidity in Europe2013In: European Respiratory Journal, ISSN 0903-1936, E-ISSN 1399-3003, Vol. 41, no 2, p. 285-294Article in journal (Refereed)
    Abstract [en]

    Ozone is a highly oxidative pollutant formed from precursors in the presence of sunlight, associated with respiratory morbidity and mortality. All else being equal, concentrations of ground-level ozone are expected to increase due to climate change. Ozone-related health impacts under a changing climate are projected using emission scenarios, models and epidemiological data. European ozone concentrations are modelled with the model of atmospheric transport and chemistry (MATCH)-RCA3 (50 x 50 km). Projections from two climate models, ECHAM4 and HadCM3, are applied under greenhouse gas emission scenarios A2 and A1B, respectively. We applied a European-wide exposure-response function to gridded population data and country-specific baseline mortality and morbidity. Comparing the current situation (1990-2009) with the baseline period (1961-1990), the largest increase in ozone-associated mortality and morbidity due to climate change (4-5%) have occurred in Belgium, Ireland, the Netherlands and the UK. Comparing the baseline period and the future periods (2021-2050 and 2041-2060), much larger increases in ozone-related mortality and morbidity are projected for Belgium, France, Spain and Portugal, with the impact being stronger using the climate projection from ECHAM4 (A2). However, in Nordic and Baltic countries the same magnitude of decrease is projected. The current study suggests that projected effects of climate change on ozone concentrations could differentially influence mortality and morbidity across Europe.

  • 36.
    Persson, Christer
    et al.
    SMHI, Research Department, Air quality.
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Robertson, Lennart
    SMHI, Research Department, Air quality.
    Regional spridningsmodell för Göteborgs och Bohus, Hallands och Älvsborgs län: A mesoscale air pollution dispersion model for the Swedish west-coast region. In Swedish with captions also in English1994Report (Other academic)
  • 37. Reckermann, Marcus
    et al.
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Omstedt, Anders
    Göteborgs Universitet.
    von Storch, Hans
    Keevallik, Sirje
    Schneider, Bernd
    Arheimer, Berit
    SMHI, Research Department, Hydrology.
    Meier, Markus
    SMHI, Research Department, Oceanography.
    Huenicke, Birgit
    BALTEX-an interdisciplinary research network for the Baltic Sea region2011In: Environmental Research Letters, ISSN 1748-9326, E-ISSN 1748-9326, Vol. 6, no 4, article id 045205Article in journal (Refereed)
    Abstract [en]

    BALTEX is an environmental research network dealing with the Earth system of the entire Baltic Sea drainage basin. Important elements include the water and energy cycle, climate variability and change, water management and extreme events, and related impacts on biogeochemical cycles. BALTEX was founded in 1993 as a GEWEX continental-scale experiment and is currently in its second 10 yr phase. Phase I (1993-2002) was primarily dedicated to hydrological, meteorological and oceanographic processes in the Baltic Sea drainage basin, hence mostly dealt with the physical aspects of the system. Scientific focus was on the hydrological cycle and the exchange of energy between the atmosphere, the Baltic Sea and the surface of its catchment. The BALTEX study area was hydrologically defined as the Baltic Sea drainage basin. The second 10 yr phase of BALTEX (Phase II: 2003-12) has strengthened regional climate research, water management issues, biogeochemical cycles and overarching efforts to reach out to stakeholders and decision makers, as well as to foster communication and education. Achievements of BALTEX Phase II have been the establishment of an assessment report of regional climate change and its impacts on the Baltic Sea basin (from hydrological to biological and socio-economic), the further development of regional physical climate models and the integration of biogeochemical and ecosystem models. BALTEX features a strong infrastructure, with an international secretariat and a publication series, and organizes various workshops and conferences. This article gives an overview of the BALTEX programme, with an emphasis on Phase II, with some examples from BALTEX-related research.

  • 38.
    Robertson, Lennart
    et al.
    SMHI, Research Department, Air quality.
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Source function estimate by means of variational data assimilation applied to the ETEX-I tracer experiment1998In: Atmospheric Environment, ISSN 1352-2310, E-ISSN 1873-2844, Vol. 32, no 24, p. 4219-4225Article in journal (Refereed)
    Abstract [en]

    The ETEX data set opens new possibilities to develop data assimilation procedures in the area of long-range transport. This paper illustrates the possibilities using a variational approach, where the source term for ETEX-I was reconstructed. The MATCH model (Robertson et at., 1996) has been the basis for this attempt. The timing of the derived emission rates are in accordance with the time period for the ETEX-I release, and a cross validation, with observations beyond the selected assimilation period, shows that the source term gained holds for the entire ETEX-I experiment. A poor-man variational approach was shown to perform nearly as good as a fully variational data assimilation. The issue of quality control has not been considered in this attempt but will be an important part that has to be addressed in future work. (C) 1998 Elsevier Science Ltd. All rights reserved.

  • 39.
    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.

  • 40.
    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)
  • 41. Rodhe, H
    et al.
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Gallardo, L
    Kjellström, Erik
    SMHI, Research Department, Climate research - Rossby Centre.
    Global scale transport of acidifying pollutants1995In: Water, Air and Soil Pollution, ISSN 0049-6979, E-ISSN 1573-2932, Vol. 85, no 1, p. 37-50Article in journal (Refereed)
    Abstract [en]

    During the past few years several attempts have been made to use three-dimensional tracer transport models to simulate the global distribution of sulfur and nitrogen compounds from both natural and anthropogenic sources. We review these studies and show examples of estimated distributions of the total deposition of sulfur, oxidized nitrogen and ammonium as well as the pH of precipitation. The simulated patterns are compared with observations. Weaknesses in these estimates resulting from lack of knowledge of emissions, chemical transformations and removal processes are emphasized and discussed. We also show examples of how the models can be used to estimate past and future deposition patterns. In particular, we use the IPCC scenario IS92a to estimate the possible sulfur deposition around the world in the year 2050. A comparison with critical load values for sulfur deposition indicates that substantial parts of South and East Asia are at risk for acidification problems in the future.

  • 42.
    Rummukainen, Markku
    et al.
    SMHI, Research Department, Climate research - Rossby Centre.
    Johansson, Daniel J.A.
    Institutionen för energi och miljö, avdelningen för fysisk resursteori, Chalmers.
    Azar, Christian
    Institutionen för energi och miljö, avdelningen för fysisk resursteori, Chalmers.
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Doescher, Ralf
    SMHI, Research Department, Climate research - Rossby Centre.
    Smith, Henrik
    Centrum för miljö och klimatforskning, Lunds universitet.
    Uppdatering av den vetenskapliga grunden för klimatarbetet2011Report (Other academic)
    Abstract [sv]

    Det naturvetenskapliga kunskapsläget om klimatförändringarna förbättrats ständigt genom forskningen om klimatsystemet, klimatpåverkan, klimatets variationer och förändringar samt klimateffekter. Kunskapsläget är väletablerat när det gäller den grundläggande fysiken bakom växthuseffekten, liksom att genomsnittstemperaturen vid jordytan stigit de senaste femtio åren. Det är också mycket sannolikt att det mesta av den observerade uppvärmningen beror på mänsklig klimatpåverkan. Samtidigt finns det betydande osäkerheter när det gäller konsekvenserna av klimatförändringarna samt hur mycket utsläppen behöver minska för att man ska nå ett givet klimatmål. Värdet på klimatkänsligheten är den viktigaste faktorn för beräkningar av hur mycket växthusgaser vi kan släppa ut, givet ett visst temperaturmål. Forskningen visar att det behövs stora och snabba utsläppsminskningar för att uppnå tvågradersmålet. För att nå ett lägre temperaturmål, till exempel ett 1,5-gradersmål, är de nödvändiga utsläppsminskningarna än mer omfattande.  För att nå tvågradersmålet med en sannolikhet runt 70 % krävs uppskattningsvis att de globala växthusgasutsläppen minskar i storleksordningen 50‒60 % från år 2000 till 2050, och minskar med nära 100 % till 2100.  För att nå ett 1,5-gradersmål med en sannolikhet runt 70 % krävs globala nollutsläpp redan runt år 2050.  För att nå ett 1,5-gradersmål med en sannolikhet runt 50 % krävs uppskattningsvis att de globala växthusgasutsläppen minskar i storleksordningen 80 % från år 2000 till 2050, och med nära 100 % till 2100. Det är framför allt de kumulativa utsläppen av koldioxid och andra långlivade växthusgaser som räknas när det gäller hur stora klimatförändringarna blir bortom 2100. Ju senare de globala utsläppen kulminerar, och ju högre nivå de då är på, desto större blir utmaningen för att åstadkomma en tillräckligt snabb påföljande utsläppsminskningstakt. Reducerade utsläpp av kortlivade klimatpåverkande ämnen är viktigt främst i ett kortare perspektiv. Det finns olika modeller för hur de globala utsläppsminskningarna kan fördelas mellan olika regioner och länder. Dessa baseras inte på naturvetenskapliga principer utan är beroende av politiska och andra ställningstaganden. För en del länder skiljer sig resultaten mycket beroende på valet av fördelningsmodell. För de flesta industriländer är slutsatsen dock generellt sett densamma: jämfört med idag behöver deras utsläpp minska mycket kraftigt.  För att nå tvågradersmålet med i storleksordningen 70 % sannolikhet krävs, givet en globalt lika per capita fördelning av utsläppen från och med 2050, att utsläppen i Sverige minskar med cirka 70 % från år 2005 till 2050. Den motsvarande siffran för EU är cirka 80 %.  För att nå ett 1,5-gradersmål med i storleksordningen 70 % sannolikhet krävs, givet en globalt lika per capita fördelning av utsläppen från och med 2050, att utsläppen minskar från år 2005 till år 2050 med runt 100 % i Sverige och i EU, och i andra länder.  För att nå ett 1,5-gradersmål med i storleksordningen 50 % sannolikhet krävs, givet en globalt lika per capita fördelning av utsläppen från och med 2050, att utsläppen i Sverige och EU minskar med drygt 90 % från år 2005 till 2050. Nettoutsläpp av koldioxid från avskogning och utrikes luft- och sjöfart ingår inte i dessa uppskattningar. Generellt blir riskerna för allvarliga klimateffekter mindre ju mer ambitiöst temperaturmål som väljs, men riskerna försvinner inte med tvågradersmålet, och inte ens med ett 1,5-gradersmål. Jämfört med IPCC:s AR4 från 2007, har nya forskningsresultat publicerats om klimateffekter. I denna rapport har vi fokuserat på havsnivåhöjningen, havsförsurningen, den biologiska mångfalden samt klimateffekter i Arktis. Jämfört med genomgången av kunskapsläget i AR4 visar nya resultat att den framtida havsnivåhöjningen kan bli större, havsförsurningens effekter på marina ekosystem omfattande och även om en del arter kan vara anpassningsbara, kan världens ekosystem påverkas av skillnader i olika arters sårbarhet för klimatförändringarna. I Arktis sker snabba förändringar. Sammantaget ter sig riskerna för allvarliga klimateffekter större jämfört med AR4. Denna rapport utgår från naturvetenskaplig klimatforskning sedan 2007. Rapporten förordar inte något specifikt temperaturmål, någon specifik utsläppsbana eller specifika policybeslut. Dessa är föremål för politiska avgöranden.

  • 43. Sand, M.
    et al.
    Berntsen, T. K.
    von Salzen, K.
    Flanner, M. G.
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Victor, D. G.
    Response of Arctic temperature to changes in emissions of short-lived climate forcers2016In: Nature Climate Change, ISSN 1758-678X, E-ISSN 1758-6798, Vol. 6, no 3, p. 286-+Article in journal (Refereed)
    Abstract [en]

    There is growing scientific(1,2) and political(3,4) interest in the impacts of climate change and anthropogenic emissions on the Arctic. Over recent decades temperatures in the Arctic have increased at twice the global rate, largely as a result of ice-albedo and temperature feedbacks(5-8). Although deep cuts in global CO2 emissions are required to slow this warming, there is also growing interest in the potential for reducing short-lived climate forcers (SLCFs; refs 9,10). Politically, action on SLCFs may be particularly promising because the benefits of mitigation are seen more quickly than for mitigation of CO2 and there are large co-benefits in terms of improved air quality(11). This Letter is one of the first to systematically quantify the Arctic climate impact of regional SLCFs emissions, taking into account black carbon (BC), sulphur dioxide (SO2), nitrogen oxides (NOx), volatile organic compounds (VOCs), organic carbon (OC) and tropospheric ozone (O-3), and their transport processes and transformations in the atmosphere. This study extends the scope of previous works(2,12) by including more detailed calculations of Arctic radiative forcing and quantifying the Arctic temperature response. We find that the largest Arctic warming source is from emissions within the Asian nations owing to the large absolute amount of emissions. However, the Arctic is most sensitive, per unit mass emitted, to SLCFs emissions from a small number of activities within the Arctic nations themselves. Astringent, but technically feasible mitigation scenario for SLCFs, phased in from 2015 to 2030, could cut warming by 0.2 (+/- 0.17) K in 2050.

  • 44. 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).

  • 45. Simpson, David
    et al.
    Bartnicki, Jerzy
    Jalkanen, Jukka-Pekka
    Hansson, Hans-Christen
    Hertel, Ole
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Pryor, Sara C.
    Environmental Impacts-Atmospheric Chemistry2015Chapter in book (Other academic)
    Abstract [en]

    This chapter addresses sources and trends of atmospheric pollutants and deposition in relation to the Baltic Sea region. Air pollution is shown to have important effects, including significant contributions to nitrogen loading of the Baltic Sea area, ecosystem impacts due to acidifying and eutrophying pollutants and ozone, and human health impacts. Compounds such as sulphate and ozone also have climate impacts. Emission changes have been very significant over the past 100 years, although very different for land-and sea-based sources. Land-based emissions generally peaked around 1980-1990 and have since reduced due to emissions control measures. Emissions from shipping have been steadily increasing for decades, but recent measures have reduced sulphur and particulate emissions. Future developments depend strongly on policy developments. Changes in concentration and deposition of the acidifying components generally follow emission changes within the European area. Mean ozone levels roughly doubled during the twentieth century across the northern hemisphere, but peak levels have reduced in many regions in the past 20 years. The main changes in air pollution in the Baltic Sea region are due to changes in emissions rather than to climate change.

  • 46. Soares, Joana
    et al.
    Sofiev, Mikhail
    Geels, Camilla
    Christensen, Jens H.
    Andersson, Camilla
    SMHI, Research Department, Air quality.
    Tsyro, Svetlana
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Impact of climate change on the production and transport of sea salt aerosol on European seas2016In: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 16, no 20, p. 13081-13104Article in journal (Refereed)
  • 47. Solberg, S
    et al.
    Bergström, Robert
    SMHI, Research Department, Air quality.
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Laurila, T
    Lindskog, A
    Changes in Nordic surface ozone episodes due to European emission reductions in the 1990s2005In: Atmospheric Environment, ISSN 1352-2310, E-ISSN 1873-2844, Vol. 39, no 1, p. 179-192Article in journal (Refereed)
    Abstract [en]

    Based on analyses of model calculations with a regional scale CTM for two different years and measurement data from background locations in northern Europe, we have found several indications that peak ozone value, in the Nordic countries have been reduced during the 1990s as a result of reduced emissions of precursors in Europe. Official European emission data for 1999 gave a better model performance than the emission data for 1990 when modelling 1999 and 2000. A bootstrap resampling technique indicated that the improvement in performance was significant. The model predicted a reduction in peak ozone values of the order of 30 mug m(-3) due to European emission reductions during the 1990s in the Nordic countries. It is thus likely that the number of exceedances of hourly threshold values has been reduced, although the small number of episodes does not allow strict statements. The number and magnitude of the ozone episodes as well as the model performance was clearly higher for southern Sweden and Norway compared to Finland, presumably reflecting differences in meteorological transport and emission source regions. (C) 2004 Elsevier Ltd. All rights reserved.

  • 48. Solberg, S
    et al.
    Derwent, R G
    Hov, O
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Lindskog, A
    European abatement of surface ozone in a global perspective2005In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 34, no 1, p. 47-53Article in journal (Refereed)
    Abstract [en]

    EU's programme Clean Air for Europe (CAFE) is presently revising the policy on air quality which will lead to the adoption of a thematic strategy on air pollution under the Sixth Environmental Action Programme by mid-2005. For the abatement of surface ozone it is becoming evident that processes outside European control will be crucial for meeting long-term aims and air quality guidelines in Europe in the future. Measurements and modelling results indicate that there is a strong link between climate change and surface ozone. A warmer and dryer European climate is very likely to lead to increased ozone concentrations. Furthermore, increased anthropogenic emissions in developing economies in Asia are likely to raise the hemispheric background level of ozone. A significant increase in the background concentration of ozone has been observed at several sites in Northern Europe although the underlying causes are not settled. The photochemical formation of tropospheric ozone from increased concentrations of methane and CO may also lead to a higher ozone level on a global scale. Gradually, these effects may outweigh the effect of the reduced European ozone precursor emissions. This calls for a global or hemispheric perspective in the revision of the European air quality policy for ozone.

  • 49.
    Thomas, Manu Anna
    et al.
    SMHI, Research Department, Air quality.
    Kahnert, Michael
    SMHI, Research Department, Air quality.
    Andersson, Camilla
    SMHI, Research Department, Air quality.
    Kokkola, H.
    Hansson, Ulf
    SMHI, Research Department, Climate research - Rossby Centre.
    Jones, Colin
    SMHI, Research Department, Climate research - Rossby Centre.
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Devasthale, Abhay
    SMHI, Research Department, Atmospheric remote sensing.
    Integration of prognostic aerosol-cloud interactions in a chemistry transport model coupled offline to a regional climate model2015In: Geoscientific Model Development, ISSN 1991-959X, E-ISSN 1991-9603, Vol. 8, no 6, p. 1885-1898Article in journal (Refereed)
    Abstract [en]

    To reduce uncertainties and hence to obtain a better estimate of aerosol (direct and indirect) radiative forcing, next generation climate models aim for a tighter coupling between chemistry transport models and regional climate models and a better representation of aerosol-cloud interactions. In this study, this coupling is done by first forcing the Rossby Center regional climate model (RCA4) with ERA-Interim lateral boundaries and sea surface temperature (SST) using the standard cloud droplet number concentration (CDNC) formulation (hereafter, referred to as the 'stand-alone RCA4 version' or 'CTRL' simulation). In the stand-alone RCA4 version, CDNCs are constants distinguishing only between land and ocean surface. The meteorology from this simulation is then used to drive the chemistry transport model, Multiple-scale Atmospheric Transport and Chemistry (MATCH), which is coupled online with the aerosol dynamics model, Sectional Aerosol module for Large Scale Applications (SALSA). CDNC fields obtained from MATCH-SALSA are then fed back into a new RCA4 simulation. In this new simulation (referred to as 'MOD' simulation), all parameters remain the same as in the first run except for the CDNCs provided by MATCH-SALSA. Simulations are carried out with this model setup for the period 2005-2012 over Europe, and the differences in cloud microphysical properties and radiative fluxes as a result of local CDNC changes and possible model responses are analysed. Our study shows substantial improvements in cloud microphysical properties with the input of the MATCH-SALSA derived 3-D CDNCs compared to the stand-alone RCA4 version. This model setup improves the spatial, seasonal and vertical distribution of CDNCs with a higher concentration observed over central Europe during boreal summer (JJA) and over eastern Europe and Russia during winter (DJF). Realistic cloud droplet radii (CD radii) values have been simulated with the maxima reaching 13 mu m, whereas in the stand-alone version the values reached only 5 mu m. A substantial improvement in the distribution of the cloud liquid-water paths (CLWP) was observed when compared to the satellite retrievals from the Moderate Resolution Imaging Spectroradiometer (MODIS) for the boreal summer months. The median and standard deviation values from the 'MOD' simulation are closer to observations than those obtained using the stand-alone RCA4 version. These changes resulted in a significant decrease in the total annual mean net fluxes at the top of the atmosphere (TOA) by -5 W m(-2) over the domain selected in the study. The TOA net fluxes from the 'MOD' simulation show a better agreement with the retrievals from the Clouds and the Earth's Radiant Energy System (CERES) instrument. The aerosol indirect effects are estimated in the 'MOD' simulation in comparison to the pre-industrial aerosol emissions (1900). Our simulations estimated the domain averaged annual mean total radiative forcing of -0.64 W m(-2) with a larger contribution from the first indirect aerosol effect (-0.57 W m(-2)) than from the second indirect aerosol effect (-0.14 W m(-2)).

  • 50. Tilmes, S
    et al.
    Brandt, J
    Flatoy, F
    Bergström, Robert
    SMHI, Research Department, Air quality.
    Flemming, J
    Langner, Joakim
    SMHI, Research Department, Air quality.
    Christensen, J H
    Frohn, L M
    Hov, O
    Jacobsen, I
    Reimer, E
    Stern, R
    Zimmermann, J
    Comparison of five eulerian air pollution forecasting systems for the summer of 1999 using the German ozone monitoring data2002In: Journal of Atmospheric Chemistry, ISSN 0167-7764, E-ISSN 1573-0662, Vol. 42, no 1, p. 91-121Article in journal (Refereed)
    Abstract [en]

    Eulerian state-of-the-art air pollution forecasting systems on the European scale are operated routinely by several countries in Europe. DWD and FUB, both Germany, NERI, Denmark, NILU, Norway, and SMHI, Sweden, operate some of these systems. To apply such modeling systems, e.g. for regulatory purposes according to new EU directives, an evaluation and comparison of the model systems is fundamental in order to assess their reliability. One step in this direction is presented in this study: The model forecasts from all five systems have been compared to measurements of ground level ozone in Germany. The outstanding point in this investigation is the availability of a huge amount of data - from forecasts by the different model systems and from observations. This allows for a thorough interpretation of the findings and assures the significance of the observed features. Data from more than 300 measurement stations for a 5-month period (May-September 1999) of the German monitoring networks have been used in this comparison. Different spatial and temporal statistical parameters were applied in the evaluation. Generally, it was found that the most comprehensive models gave the best results. However, the less comprehensive and computational cheaper models also produced good results. The extensive comparison made it possible to point out weak points in the different models and to describe the individual model behavior for a full summer period in a climatological sense. The comparison also gave valuable information for an assessment of individual measurement stations and complete monitoring networks in terms of the representativeness of the observation data.

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