Time filter

Source Type

Copenhagen, Denmark

Gsella A.,European Environment Agency EEA | De Meij A.,The Cyprus Institute | Kerschbaumer A.,Free University of Berlin | Reimer E.,Free University of Berlin | And 2 more authors.
Atmospheric Environment | Year: 2014

The objective of this study was to evaluate three meteorological models (MM5, WRF and TRAMPER) by comparing the calculated meteorological parameters with observations over the Po Valley area (Italy) for 2005. The analysis shows that MM5 and WRF perform with similar quality, with advantages of WRF at following high resolution time patterns and better scores of MM5 at reproducing annual averages, noticed for precipitation and relative humidity calculations. Results from the TRAMPER model also reflect very well surface meteorological measurements, they may be however driven by data assimilation applied in this modelling system and thus strongly influenced by very local effects. This feature of TRAMPER may lead as well to large uncertainties in reproducing other parameters important for air quality modelling such as planetary boundary layer (PBL) heights, friction velocity (u*) values or stability conditions. © 2014 Elsevier Ltd. Source

Giannouli M.,Aristotle University of Thessaloniki | Kalognomou E.-A.,Aristotle University of Thessaloniki | Mellios G.,Aristotle University of Thessaloniki | Moussiopoulos N.,Aristotle University of Thessaloniki | And 2 more authors.
Atmospheric Environment | Year: 2011

The aim of this study is to investigate the effects of specific emission control measures on the air quality of urban centres and local area hotspots. In order to achieve this, a sequence of regional, urban and local scale models was applied to assess the impact of European emission control strategies on urban and local scale air quality. First, vehicle fleet and activity data were estimated using appropriate models. The results of these models were used as input to the COPERT model in order to estimate vehicle emissions (NO2 and PM10) at country level up to the year 2030. Vehicle emissions were calculated according to two different scenarios: A baseline scenario, CLE (Current LEgislation) and an optimistic alternative, MFR (Maximum Feasible Reductions). Urban background and traffic hotspot concentrations of air pollutants were then calculated using the OFIS (Ozone FIne Structure) and OSPM (Operational Street Pollution Model) models respectively for 20 cities in Europe and for particular types of streets. Air quality was found to improve in 2030 compared to the reference year 2000, in line with the stricter NOx and PM vehicle emission limits imposed. The NO2 street increments for narrow canyons estimated for the reference year were found to be in the range of 16-53 μg m-3, depending on the city considered. These were reduced to 14-36 μg m-3 in the CLE scenario and 7-24 μg m-3 in the MFR scenario. The corresponding range for PM10 was estimated to be 5-15 μg m-3 for the reference year and was reduced to 2-8 μg m-3 and 0.2-2.4 μg m-3 for the CLE and the MFR scenarios respectively. © 2010 Elsevier Ltd. Source

Pernigotti D.,European Commission - Joint Research Center Ispra | Thunis P.,European Commission - Joint Research Center Ispra | Cuvelier C.,European Commission - Joint Research Center Ispra | Georgieva E.,Bulgarian Academy of Science | And 14 more authors.
Air Quality, Atmosphere and Health | Year: 2013

The Po Valley (Italy) model inter-comparison exercise (POMI) has been carried out in order to explore the changes in air quality in response to changes in emissions. The starting point was the evaluation of the simulated particulate matter and ozone (O3) modelled concentrations against observations for the year 2005 of the six participating chemical transport models. As models were run with the same configuration in terms of spatial resolution, boundary condition, emissions and meteorology, the differences presented in the models' results are only related to their formulation. As described in the paper, significant efforts have been made to improve the accuracy of the anthropogenic emissions and meteorological input data. Nevertheless, none of the models using the proposed meteorology succeeded to fulfil the quality performance criteria set in the 2008 Air Quality Directive and in the literature for particulate matter, while also for ozone the results are not very satisfying. Although the overall performances look better for O3 than for particulate matter with an aerodynamic diameter smaller than 10 μm (PM10), the models tend to exhibit a similar behaviour and show the largest model variability in locations where concentrations are the highest (urban areas for PM10 and suburbs and hilly areas for O3). While differences are significant in terms of standard deviation and bias, the correlation remains quite similar among models indicating that models generally capture well the main temporal variations, especially the seasonal ones. Possible explanations for this common behaviour and a discussion of the differences among models' results are presented in this paper. © 2013 Springer Science+Business Media Dordrecht. Source

Sharma A.K.,Technical University of Denmark | Guildal T.,Avedoere Wastewater Services | Thomsen H.R.,Kruger Veolia Water Solutions and Technologies | Jacobsen B.N.,European Environment Agency EEA
Water Science and Technology | Year: 2011

The aim of this project was to investigate the potential of reducing number of mixers in the biological treatment process and thereby achieve energy and economical savings and contribute to cleaner environment. The project was carried out at Avedoere wastewater treatment plant and a full scale investigation was conducted to study the effect of reduced mixing on flow velocity, suspended solid sedimentation, concentration gradients of oxygen and SS with depth and treatment efficiency. The only negative effect observed was on flow velocity; however the velocity was above the critical velocity. The plant has been operating with 50% of its designed number of mixers since September 2007 and long term results also confirm that reduced mixing did not have any negative effect on treatment efficiency. The estimated yearly electricity saving is 0.75 GWh/year. © IWA Publishing 2011. Source

Bessagnet B.,INERIS | Beauchamp M.,INERIS | Guerreiro C.,Norwegian Institute For Air Research | de Leeuw F.,National Institute for Public Health and the Environment RIVM | And 9 more authors.
Environmental Science and Policy | Year: 2014

Several studies point out the importance of agricultural emissions to particulate matter (PM) concentrations, and particularly of NH3 emissions to PM2.5. Our study used three different chemical transport models (CHIMERE, EMEP and LOTOS-EUROS) to quantify the reductions of PM2.5 and PM10 concentrations due to reductions of NH3 emissions beyond the Gothenburg Protocol (GP), as well as due to the GP alone compared to 2009. Simulations of PM2.5 and PM10 concentrations using 2009 meteorology were undertaken for five emission scenarios: 2009 emissions (as the reference simulation), GP emissions in 2020, and further 10%, 20% and 30% NH3 emission reductions in EU27 beyond the GP. The modelling results for the scenarios with further 10%, 20% and 30% NH3 agriculture emission reductions in EU27 beyond the GP show that the reduction achieved in PM concentrations is not linear with the emission reductions. In fact, the results from the study show that the impact of ammonia emissions reduction is significantly more efficient when the emission reduction rises. Moreover, based on the evaluation on 2009, the modelling study shows that the expected impact of ammonia emissions on the formation of particulate ammonium was underestimated by all models. This would imply that the role of ammonia on PM concentration and exceedances of PM2.5 and PM10 limit values is likely to be even larger than quantified in this study. This study shows that the implementation of the emission reductions imposed by the revised GP for 2020 will not suffice to achieve compliance with PM limit values everywhere in Europe; hence further European and local measures may be considered. NH3 emissions from agriculture can be further reduced with the implementation of proven and feasible measures (substitution of fertilizers, improved storage of manure, way fertilizer injections, etc., . . .), in order to reduce PM concentrations and their impacts on human health across Europe. © 2014 Elsevier Ltd. Source

Discover hidden collaborations