1,721,024 research outputs found
Sulphur simulations for East Asia using the MATCH model with meteorological data from ECMWF
No full textAs part of a model intercomparison exercise, with participants from a number of Asian, European and American institutes, sulphur transport and conversion calculations were conducted over an East Asian domain for 2 different months in 1993. All participants used the same emission inventory and simulated concentration and deposition at a number of prescribed geographic locations. The participants were asked to run their respective model both with standard parameters, and with a set of given parameters, in order to exarnine the different behaviour of the models. The study included comparison with measured data and model-to-model intercomparisons, notably source-receptor relationships. We hereby describe the MATCH model, used in the study, and report some typical results. We find that although the standard and the prescribed set of model parameters differed significantly in terms of sulphur conversion and wet scavenging rate, the resulting change in atmospheric concentrations and surface depositions only change marginally. We show that it is often more critical to choose a representative gridbox value than selecting a parameter from the suite available. The modelled, near-surface, atmospheric concentration of sulphur in eastem China is typically 5-10 μg S m-3, with large areas exceeding 20 μg S m-3. In southem Japan the values range from 2-5 μg Sm-3. Atmospheric SO2 dominates over sulphate near the emission regions while sulphate concentrations are higher over e.g. the western Pacific. The sulphur deposition exceeds several g sulphur m-2 year-1 in large areas of China. Southem Japan receives 0.5-1 g S m-2 year-1. In January, the total wet deposition roughly equals the dry deposition, in May - when it rains more in the domain - total wet deposition is ca. 50% larger than total dry deposition
Model simulations of anthropogenic-CO2 transport to an Arctic monitoring station during winter
No full textWe describe, and use, a limited area, 3-dimensional transport model. The model domain is located over the Arctic, but includes the majority of the anthropogenic CO2 emissions in western and eastern Europe, which together make up about 1/3 of the global CO2 emissions. The model is run for several winter periods, using anthropogenic CO2 emissions only, and the results are compared with independent CO2 measurements taken at a monitoring station on Spitsbergen in the high Arctic. We show that the initial concentrations and boundary values of the domain are not crucial for the results, and conclude that most of the measured variability above the winter baseline in CO2 at the Arctic monitoring station emanates from recent CO2 sources within the model domain. From the observed small spatial variability in the monthly mean atmospheric CO2 mixing ratio in the north Atlantic region, we assume that there is only little net exchange between the atmosphere and ocean during the studied periods. Based on the co-variation between CO2 and particulate mass,we hypothesise that most of the measured CO2 variability is due to anthropogenic fossil fuel emissions, although we can not rule out a biogenic CO2 component. Using the transport model, we compare different estimates of fossil-fuel consumption in the mid-latitudes. We find that the industrial centres and the surrounding gas-fields in the lower-Ob region (60 degrees-72 degrees N, 65 degrees-80 degrees E) occasionally have a much larger impact on the CO2 measurements at Spitsbergen than follows from a recent CO2 emission inventory. This implies that there may be an overlooked CO2 source in this region, possibly flaring of gas
Luftföroreningar i Europa under framtida klimat
No full textOzonmedelhalterna förväntas öka markant (1-2% per decennium, fram till 2050) i centrala och södra Europa, framförallt under sommaren. Maximumhalterna ökar mer än medelhalterna.Nordligaste Europa förväntas få minskande halter, speciellt under vår och höst.Östra Europa får minskande ozonhalter under vintern. I södra Skandinavien ser vi bara småförändringar i ozonhalterna under alla årstider.Halten av marknära sekundära inorganiska partiklar (SIA; Secondary Inorganic Aerosols)ökar kraftigt (3-5% per decennium, fram till 2050) i hela kontinentala Europa under allaårstider förutom vinter. Ökningen är störst runt Medelhavet på sommaren, och halterna är merän 20% högre under 30-års perioden 2021-2050 jämfört med dagens nivåer. 2071-2100beräknas partikelhalterna under sommaren vara minst 50% högre, jämfört med dagenssituation, i stora områden av södra och centrala Europa. Södra Skandinavien torde få enmåttlig ökning av SIA under framförallt under vår och sommar. Nordliga delar avmodellområdet uppvisar minskande SIA halter under alla årstider.Våtdepositionen av svavel- och kväveföreningar minskar mycket kraftigt i södra och västraEuropa under alla årstider, speciellt under den senare delen av simuleringsperioden (2021-2050 till 2071-2100). Stora områden i och kring Medelhavet samt delar av Frankrike, Belgienoch Nederländerna får endast 50%, eller mindre, av dagens deposition under perioden 2071-2100. Norges kust förväntas få en ökad våtdeposition i framtida klimat, speciellt under vårenoch sommaren. Ökningen är större än 50% på flera platser, men det är trots allt en relativtliten yta som påverkas på detta sätt. Minskad (ökad) våtdeposition i modellområdetkompenseras i någon mån av ökad (minskad) torrdeposition. För de flesta områdena kommerdock ändringen i totaldeposition att följa mönstret i våtdepositionen.Resultaten tyder på att flera sekundära luftföroreningar blir mer långlivade. Halterna iatmosfären blir därmed högre, de kommer vidare att kunna spridas över större områden.In order to investigate the effects of climate change on air quality in Europe, we have utilised the regional CTM (chemistry and transport model) MATCH, forced by meteorology representing future climate conditions but keeping the emissions at their current value. The meteorology is from RCA3, the Rossby Center’s regional climate model (covering all Europe on 50 km × 50 km resolution). RCA3 is, in the current study, run under the SRES A2 emission scenario forced with corresponding climate data from ECHAM4/OPYC3 global model on its boundaries. We have applied our CTM on three different 30-year periods representing current, near- and distant future climate (1961-1990, 2021-2050 and 2071-2100, respectively). Detailed description and validation of the climate model and the CTM is given elsewhere. In the present report we report seasonally-averaged changes in near-surface ozone, secondary inorganic aerosols (SIA) and deposition of sulphur and nitrogen containing species in Europe.The seasonal-mean ozone concentrations are expected to increase considerably (1-2% per decade up to 2050) in central and southern Europe, in particular during summer. The daily maximum concentrations are expected to increase even more than the daily mean concentrations. Northernmost Europe is projected to experience lower ozone concentrations under future climate, especially during spring and autumn. The concentration of SIA will increase dramatically in continental Europe during all seasons except winter. The increase is largest around the Mediterranean during summer. The average summertime concentration of SIA will be 20% higher in 2021-2050 and 50% higher in 2071-2100 compared to current levels as a result of changing the meteorology (drier and warmer conditions in central and southern Europe). The increase in atmospheric SIA concentrations is related to the large decrease in wet deposition of sulphur- and nitrogen containing species, which will be the consequence of climate change in large parts of central and southern Europe. Large areas around the Mediterranean, France, Belgium and the Netherlands will receive 50%, or less, of current nitrogen- and sulphur deposition in 2071-2100 compared to present conditions. The Norwegian coast, on the other hand, is expected to receive more sulphur- and nitrogen deposition due to the anticipated increase in precipitation in this area
Deposition of sulphur and nitrogen in Europe 1900–2050. Model calculations with EMEP and MATCH models.
No full textThe data-repository contains chemical transport model results (S- and N- deposition, and ozone) for the period 1900-2050 from the EMEP MSC-W and MATCH models, as used in the paper:
* Engardt, M., Simpson, D., Schwikowski, M., Granat, L., 2017. Deposition of sulfur and nitrogen in Europe 1900–2050. Model calculations and comparison to historical observations. Tellus Ser. B Chem. Phys. Meteorol. 69 (1):1328945. http://dx.doi.org/10.1080/16000889.2017.1328945.
The zip file (which unpacks to ca. 500 Mb) consists of ascii data-files for all years and many components. See the enclosed README.txt for more details.This work was funded by the EU FP7 projects ECLAIRE [Project number 282910] and PEGASOS [Project number 265148],
the Nordic Council of Ministers EnsClim project, and the Swedish EPA under the CLEO programme (Climate Change and
Environmental Objectives), as well as EMEP under UN-ECE. Computer time for EMEP model runs was supported by the
Research Council of Norway (Programme for Supercomputing)
A regional model for surface ozone in Southeast Asia
No full textAs part of the model intercomparison study MICS Asia II, the Swedish MATCH model was set up for Southeast and East Asia. In that study, the comprehensive photochemistry scheme of MATCH was used for the first time in Asia. The current work focuses on results of surface ozone from the MATCH model simulations falling outside the model intercomparison study. Model results of surface ozone concentrations for the entire year of 2001 were investigated and compared with measurements in Southeast Asia. The model produced higher surface ozone concentrations than the observations at all of the non-remote stations investigated but underestimated during the dry season at remote locations. Modelled seasonal variation was similar to, but less pronounced than, the variation in the measurements. This study indicates that NO(x) is the limiting precursor for ozone production in the model, while the fractionation in different species and total amount of non-methane volatile organic compounds (NMVOC) emissions are less important. Naturally emitted NMVOC, isoprene, is an important precursor of surface ozone at certain conditions, and a better inventory of these emissions is needed. Deposition velocities of ozone also have impact on surface concentrations. To improve the model performance, it is important to add a land use inventory with corresponding deposition velocities
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Atmospheric input of nitrogen to the Baltic Sea basin : present situation, variability due to meteorology and impact of climate change
Get PDFWe 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
PODY-beräkningar med MATCH Sverigesystemet
No full textVi har utvecklat ett programpaket som möjliggör PODY beräkningar i MATCH Sverigesystemet. Rapporten ger en kortfattad introduktion till PODY och går igenom implementeringen i MATCH-systemet. Resultat för receptorerna generic crops (POD3gen-CR) och generic deciduous trees (POD1gen-DT) presenteras för åren 2013-2015 och jämförs med motsvarande data från EMEP-modellen. POD3gen-CR uppvisar stor år-till-år variation och MATCH-resultaten är tydligt högre än motsvarande uppskattningar av EMEP-modellen. POD1gen-DT varierar mindre från år till år och resultaten från MATCH och EMEP-modellen överensstämmer bättre. PODY presenteras tillsammans med övriga ozonmått på SMHI:s miljöövervakningssida (www.smhi.se/klimatdata/miljo/atmosfarskemi) med start från miljöövervakningsåret 2013.We have developed a set of programs that enable PODY calculations in the air quality surveillance system MATCH Sverigesystemet. This report gives a brief overview of PODY calculations in general and the MATCH implementation in particular. We present results for the receptors generic crops (POD3gen-CR) and generic deciduous trees (POD1gen-DT) for the years 2013-2015 and contrast these with corresponding data from the EMEP-model. The POD3gen-CR values calculated by MATCH feature large inter-annual variations and are significantly higher than the corresponding assessment by the EMEP-model. POD1gen-DT show smaller inter-annual variation and the MATCH and the EMEP-model results correspond better. PODY is presented together with other ozone metrics on the SMHI environmental mapping web page (www.smhi.se/klimatdata/miljo/atmosfarskemi) starting from the mapping year 2013
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