62 research outputs found

    Atmospheric input of nitrogen to the Baltic Sea basin : present situation, variability due to meteorology and impact of climate change

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    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

    Seasonality of global and Arctic black carbon processes in the Arctic Monitoring and Assessment Programme models

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    This study quantifies black carbon (BC) processes in three global climate models and one chemistry transport model, with focus on the seasonality of BC transport, emissions, wet and dry deposition in the Arctic. In the models, transport of BC to the Arctic from lower latitudes is the major BC source for this region. Arctic emissions are very small. All models simulated a similar annual cycle of BC transport from lower latitudes to the Arctic, with maximum transport occurring in July. Substantial differences were found in simulated BC burdens and vertical distributions, with Canadian Atmospheric Global Climate Model (CanAM) (Norwegian Earth System Model, NorESM) producing the strongest (weakest) seasonal cycle. CanAM also has the shortest annual mean residence time for BC in the Arctic followed by Swedish Meteorological and Hydrological Institute Multiscale Atmospheric Transport and Chemistry model, Community Earth System Model, and NorESM. Overall, considerable differences in wet deposition efficiencies in the models exist and are a leading cause of differences in simulated BC burdens. Results from model sensitivity experiments indicate that convective scavenging outside the Arctic reduces the mean altitude of BC residing in the Arctic, making it more susceptible to scavenging by stratiform (layer) clouds in the Arctic. Consequently, scavenging of BC in convective clouds outside the Arctic acts to substantially increase the overall efficiency of BC wet deposition in the Arctic, which leads to low BC burdens and a more pronounced seasonal cycle compared to simulations without convective BC scavenging. In contrast, the simulated seasonality of BC concentrations in the upper troposphere is only weakly influenced by wet deposition in stratiform clouds, whereas lower tropospheric concentrations are highly sensitive.Key PointsSeasonal variations of black carbon (BC) mass budgets in the Arctic are simulatedGood agreement in simulated annual mean transport of BC to the Arctic in modelsConvective wet removal is important for differences in modeled BC concentrationPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/133539/1/jgrd53064-sup-0001-SI.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/133539/2/jgrd53064.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/133539/3/jgrd53064_am.pd

    The vulnerability of northern European vegetation to ozone damage in a changing climate. An assessment based on current knowledge

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    The potential vulnerability of vegetation at northern latitudes to ozone damage was assessed based on current knowledge with regard to air ozone concentrations and leaf ozone uptake as well as to plant traits affecting ozone tolerance. The focus was on the northern European arctic, alpine and northern boreal vegetation zones, with a special focus on high-altitude vegetation. In particular, we analysed if there are increasing risks for ozone impacts on northern vegetation due to high spring ozone concentrations in relation to climate change induced shifts such as e.g. an earlier start of the growing season. The current state of knowledge implies that ecosystems in the far north are not more susceptible to ozone than vegetation in other parts of Europe. Hence, we cannot advocate for a stronger reduction of ozone precursors emissions based exclusively on the ozone sensitivity of vegetation in the far north. Thus, policies designed to reduce emissions of ozone precursors to protect vegetation in other parts of Europe as well as in the entire northern hemisphere are likely to suffice to protect vegetation in northern Fennoscandia.The report describes an assessment of the potential vulnerability of far northern European vegetation to ozone damage in a changing climate. Scientists from Sweden, Norway and Finland have joined in and the assessments rely on the experience and expertise of the authors. We could not find evidence that expected changes in ozone concentrations and climate would make the northern arctic, alpine and subalpine vegetation substantially more vulnerable to ozone than other types of European vegetation

    Evaluating modelled tropospheric columns of CH4_4 , CO, and O3_3 in the Arctic using ground-based Fourier transform infrared (FTIR) measurements

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    This study evaluates tropospheric columns of methane, carbon monoxide, and ozone in the Arctic simulated by 11 models. The Arctic is warming at nearly 4 times the global average rate, and with changing emissions in and near the region, it is important to understand Arctic atmospheric composition and how it is changing. Both measurements and modelling of air pollution in the Arctic are difficult, making model validation with local measurements valuable. Evaluations are performed using data from five high-latitude ground-based Fourier transform infrared (FTIR) spectrometers in the Network for the Detection of Atmospheric Composition Change (NDACC). The models were selected as part of the 2021 Arctic Monitoring and Assessment Programme (AMAP) report on short-lived climate forcers. This work augments the model–measurement comparisons presented in that report by including a new data source: column-integrated FTIR measurements, whose spatial and temporal footprint is more representative of the free troposphere than in situ and satellite measurements. Mixing ratios of trace gases are modelled at 3-hourly intervals by CESM, CMAM, DEHM, EMEP MSC-W, GEM- MACH, GEOS-Chem, MATCH, MATCH-SALSA, MRI-ESM2, UKESM1, and WRF-Chem for the years 2008, 2009, 2014, and 2015. The comparisons focus on the troposphere (0–7 km partial columns) at Eureka, Canada; Thule, Greenland; Ny Ålesund, Norway; Kiruna, Sweden; and Harestua, Norway. Overall, the models are biased low in the tropospheric column, on average by −9.7 % for CH4_4, −21 % for CO, and −18 % for O3_3. Results for CH4_4 are relatively consistent across the 4 years, whereas CO has a maximum negative bias in the spring and minimum in the summer and O3_3 has a maximum difference centered around the summer. The average differences for the models are within the FTIR uncertainties for approximately 15 % of the model–location comparisons

    Is the ozone climate penalty robust in Europe?

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    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

    Modellsimuleringar av luftkoncentration och deposition av Cs137 från Tjernobylolyckan 1986

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    Model simulations of air concentration and deposition of Cs137 from the Chernobyl accident. Model results are available for the European domain at six hour time resolution and a geographical resolution of 50 km. The files in this dataset correspond to part of the model results presented by Langner et al., Atmospheric Environment, 32, 4325-4333, 1998. Concentrations at ten model levels and accumulated dry, wet and total (wet+dry) deposition of Cs137 at one hour intervals for the time period 1986-04-25 19 UTC to 1986-05-10 12 UTC are stored in NetCDF-format. The model results correspond to the simulation using precipitation from KNMI. The units are Bq m-3 and kBq m-2 respectively. Coordinate information is given in the NetCDF files. The NetCDF files also include surface pressure, surface geopotential and model calculated boundary layer heights at six hour intervals. Further details about the model simulations can be found in Langner et al. (1998).Modellsimuleringar av luftkoncentration och deponering av Cs137 från Tjernobylolyckan. Modellresultat finns tillgängliga för det europeiska området med sex timmars upplösning och en geografisk upplösning på 50 km. Se engelska katalogsidan för mer detaljer: https://snd.gu.se/en/catalogue/study/ECDS006

    A mesoscale air pollution dispersion model for the Swedish west-coast region. I : Regional air environment analysis for 1991

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    MATCH-Västkusten is a dispersion model for the three counties of Göteborg-Bohus, Hallandand Älvsborg on the Swedish west-coast. MATCH stands for "Mesoscale Atmospheric Transportand CHemistry model" and is an Eulerian atmospheric dispersion model, including physicaland chemical processes goveming sources, atmospheric transport and sinks of oxidizedsulphur and oxidized and reduced nitrogen.U sing the MATCH-Västkusten system, air pollution contributions from diff erent source typeslike traffic, industry, shipping, farming etc. can be obtained. Using a combination of air andprecipitation chemistry measurements and the MATCH-Västkusten model, also the contributionof air pollution and deposition from long range transport can be quantified in the model region.In the report, many results from the air pollution assessment studies for the year 1991 arepresented. As examples of result can be mentioned that the sources within the west-coastregion account for a substantial fraction of the total NO2-concentration, while the deposition ofsulphur and nitrogen is dominated by the long range transport. Detailed values of the differentcontributions are given in the report.MATCH-Västkusten är en regional spridningsmodell för Göteborgs och Bohus, Hallands och Älvsborgs län. Modellen, som utvecklats av SMHI på uppdrag av länsstyrelserna i de tre västkustlänen, skall vara ett redskap i det framtida regionala luftmiljöarbetet. MATCH, som står för "Mesoscale Atmospheric Transport and CHemistry model", är ett system för regional spridningsmodellering, som kan tillämpas för olika områden och med varierande geografisk upplösning. I det här fallet har en detaljerad anpassning av MATCH-systemet gjorts till västkustregionen. Med hjälp av modellen kan beräkningar göras av tex svavel- och kvävenedfallet inom olika delar av regionen, och detta kan sedan sättas i relation till kritiska belastningsgränser för hur mycket naturen tål. Därmed fås ett bra underlag för planering av nödvändiga åtgärder, som att införa utsläppsbegränsningar eller bestämma kalkningsbehov för skogar eller vattendrag. Andra frågor, som skall kunna besvaras, är t ex: Hur stor del av föroreningarna kommer från utlandet? Hur mycket bidrar den egna industrin med? Ger den tunga trafiken större bidrag än jordbruket? Vilka effekter får olika samhällsbeslut på luftmiljön - nu och i framtiden? I modellen görs beräkningar av spridning, torrdeposition, våtdeposition och kemiska reaktioner mellan följande kemiska föreningar: svaveldioxid (S02), ammoniumsulfat ((NH4) 2S04 och NH4HS04), övriga sulfatpartiklar (SO42-) kväveoxid (NO), kvävedioxid (N02), ammoniumnitrat (NH4N03), andra nitratpartiklar (NQ3·), salpetersyra (HN03) och ammoniak (NH3). En lokal anpassning av 03-halten inom modellområdet görs också. Emissionsdata, som utnyttjats vid beräkningarna, har tagits fram genom ett samarbete mellan myndigheter inom de tre länen. Den databashanterare, som utnyttjats, har utvecklats av lndic AB. De meteorologiska analyser, som ligger till grund för spridningsberäkningama, bygger på data från ett stort antal meteorologiska stationer och mätmaster. De erhållna analyserna utnyttjas därefter till att driva själva spridningsmodellen, varvid simuleringar av koncentration i luft och deposition i mark, vatten och vegetation av föroreningar emitterade inom de tre västkustlänen kan erhållas. Med hjälp av modellberäkningarna, som kombineras med mätdata från sex stycken bakgrundsstationer för föroreningsmätningar i luft och nederbörd, kan även den långväga föroreningstransporten från källor utanför Sverige kvantifieras inom olika delar av modellområdet. Metodiken innebär, att den höga upplösningen i MATCH-Västkusten ger en geografiskt mycket mer detaljerad tolkning av den långväga förorenings transportens betydelse, än vad direkta beräkningar på europaskala kan ge. De föroreningsstationer, som utnyttjas, drivs av Institutet för Vatten- och Luftvårdsforskning (IVL), Norsk lnstitutt for Luftforskning (NILU) och Statens Lantbruksuniversitet (SLU). MATCH-Västkusten har hittills utnyttjats för en luftmiljöanalys för år 1991. Koncentrationer i luft och deposition till mark, vegetation och vatten har beräknats för oxiderade svavelföreningar, oxiderade och reducerade kväveföreningar och kolväten. Långtransportens betydelse, betydelsen av de tre västkustlänens egna utsläpp samt betydelsen av delbidrag från olika källtyper inom länen har beräknats. Följande delbidrag har hittills studerats: tung trafik, personbilstrafik, tung trafik Göteborg, personbilstrafik Göteborg, industri, energiproduktion, sjöfart, jordbruk, skogsbruk, arbetsfordon, Göteborg totalt, Stenungsund totalt, Scanraff totalt och hushåll. I talet med att emissionsdata förnyas eller att olika framtidsscenarier skall studeras kan givetvis nya beräkningar göras. Några exempel på resultat: Av miljöanalysen för år 1991 framgår att NOP-länens bidrag till SO2-, NO2- och NH3-halten i luft är av ungefär lika stor betydelse som den långväga transportens bidrag, även om den geografiska fördelningen givetvis varierar. För depositionen är däremot långtransportbidragen helt dominerande. Den totala årliga svaveldepositionen är i södra delen av modellområdet ca 1 500 mg S/m2 och i den norra delen ca 800 mg S/m2, NOP-bidraget utgör endast ca 5 %. Depositionen av oxiderat kväve är i de södra delarna ca 1 000 mg N/m2 och i de norra delarna ca 550 mg N/m2 med ett bidrag från NOP-länens källor i storleksordningen 10%. För deposition av reducerat kväve har NOP-länens egna källor något större betydelse, ca 20%, och totalvärdena är ca 900 mg N/m2 i södra och ca 370 mg N/m2 i norra delen av modellområdet. Samtliga resultat avseende dygnsvärden, månadsvärden och årsvärden från luftmiljöstudien för 1991 finns tillgängliga på arbetsstationer, som finns hos uppdragsgivarna, för vidare bearbetning och presentation. I samband med beräkningarna har ett omfattande arbete lagts ner på att verifiera modellresultaten mot uppmätta halter och kvalitetssäkra det framtagna materiale

    MATCH - Meso-scale Atmospheric Transport and Chemistry modelling system : Basic transport mode/ description and control experiments with 222Rn

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    A limited area, off-line, 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 off- line 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 simulation of the atmospheric distribution of 222Rn demonstrates the ability of the model to meet the requirements of mass conservation and positiveness and to produce realistic simulations of a simple atmospheric tracer

    European scale modeling of sulfur, oxidized nitrogen and photochemial oxidants : Model development and evaluation for the 1994 growing season

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    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

    European summer surface ozone 1990-2100

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    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
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