ATMOSPHERIC POLLUTION

Author: GARCÍA VIVANCO MARTA.
Year: 2004.
University: COMPLUTENSE DE MADRID [www.ucm.es].
Place of defense: FACULTAD CIENCIAS FÍSICAS.
Place of preparation: FACULTAD DE CC. FÍSICAS.

Summary: The complexity that characterizes the chemical formation of ozone has led to an increased use of photochemical models in the field of management of ozone pollution. The models eulerianos have undergone a significant evolution in recent years and there are many existing models today that can predict ozone concentrations, both regionally and urban. The serious deterioration of air quality that affects the RMSP, especially in regard to particulate matter and ozone, necessitates the establishment of control measures to achieve a decrease in levels in the atmosphere of both pollutants. In this study we explored the potential use of a photochemical model in reducing ozone in the RMSP, validating his capacity as a tool for evaluating emission control strategies in an episode passed in August 1999. Moreover, as a preliminary step, we assessed vehicle emissions of the RMSP estimated in the official inventory for 1999 through a technique such as "top-down" (from the observed concentrations of certain pollutants), which indicated a significant overstatement of NOx levels estimated in the emission inventory (overestimate of 100%) and a slight underestimation of the HCNM. The application of photochemical model for ILC day lO, 11 and August 12, according to a scenario of emissions suitably amended (increased emissions HCNM by a factor 1.2 and low NOx emissions by a factor 0.5), showed a according to the figures calculated by the model and observations obtained satisfactory results of the evaluation and graphical statistical ozone calculated by the model. The results of the evaluation model ILC, in line with the study of "top-down" made from ambient concentrations of CO, NOx YHCNM supporters, therefore, the hypothesis of an underestimation of the HCNM, and the over - NOx emission inventory in the ESTESB for 1999, which, in turn, reveals the presence of problems of estimating NOx emitted by the heavy vehicles. The satisfactory evaluation of the model results suggests the photochemical model CIT as a suitable tool for the management of ozone pollution in Sao Paulo.

Author: AREVALO ROA GUSTAVO ELIECER.
Year: 2005.
University: POLITÉCNICA DE CATALUÑA [www.upc.edu].
Place of defense: AULA 28.8 DE ETSEIB.
Place of preparation: ETSEIB, EDIFICI H PLANTA 10 Campus SUD.

Summary: The study of the problem of air pollution in the Community of Valencia is subject to complex interactions between weather conditions, the temporal and spatial variation of emissions and the complex topography. In this regard, the use of chemical transport models, is a very useful tool to learn their dynamics, which in turn requires modeling of emissions inventories for its implementation. The Release Inventory of the Valencian Community by the year 2000 (EMIVAL2000), is a model of emission inventory implemented in a GIS and ready to be used in photochemical modeling. EMIVAL2000 allows the estimation of emissions of major pollutants primary NOx, SO2, CO, COVNMs, particulate matter, as well as the major greenhouse gas CO2, N2O, CH4, with a spatial resolution of 1 km2 and temporary 1 hour, for biogenic emission sources, traffic, industry and power generation, and domestic sectors, commercial and municipal waste management. To estimate emissions from biogenic sources of emissions and vehicular traffic, we have used the computer program implemented in the Laboratory of Environmental Modeling UPC (Parra, 2004), which has been fed with the data base of its own the Valencia region, according to the methodology proposed by Guenther et al. (1993) for the estimation of biogenic emissions and methodologies EMEP / CORINAIR for estimating emissions from vehicular traffic. To estimate emissions from industrial and power generation and domestic sector and trade have been used mainly methodologies EMEP / CHIEF CORINAIR and the USEPA. For the estimation of biogenic emissions of COVBs have taken into account the emission of isoprene, monoterpenes and OCOVBs. The information basis for the estimation regarding land use has been obtained from the Land Use of CORINE Land Cover 2000, the emission factors and biomass collected by Gomez (1998) for Catalonia and data of air temperature and overall INM solar radiation, and CEAM MTS year 2000. The model for calculating emissions from traffic is input variables: the road network (roads and highways, roads and urban), the intensity of traffic (IMD), composition of the fleet, speed of movement by type of track data air temperature profiles temporary traffic characteristics of fuels, long-distance and characteristics of the vehicle fleet. The model considers emissions rates at issue in cold, hot, evaporative and brake and tire wear. It has been included with IMD tracks more than 3000 vehicles have been selected 55 cycles per month and by type of day (labor and festive) and 13 profiles schedules for weekdays and holidays, and 7 cycles speed. To estimate emissions in industry and power generation are included sectors: cement, refining, power generation system in regular and special regime (CHP), car manufacturing, manufacturing of ceramic tile, and fried enamels, bricks and tiles, glass production, siderometalúrgica, finished textile printing activities, furniture, footwear, leather preparation, tanning and finishing, manufacture of paint and plastics manufacturing. The biogenic emission sources are responsible for 42.2% of 8 the emis 382 ions COVNMs, followed by vehicular traffic with 33%, and the same vehicular traffic is responsible for 63% of NOx emissions from 93.4% CO, from 55.5% in particulate emissions and 33.4% of CO2 emissions.

Author: PEREZ GARCIA-PANDO CARLOS.
Year: 2005.
University: POLITÉCNICA DE CATALUÑA [www.upc.edu].
Place of defense: Aula CAPILLA, PLANTA BAJA DE LAS ETSEIB.
Place of preparation: ETSEIB, EDIFICI H PLANTA 10 Campus SUD.

Summary: This multidisciplinary study is mainly based on the combination of atmospheric modeling and aerosol lidar measurements to explore a variety of atmospheric processesâinteracting from local to regional scalesâin the Mediterranean troposphere. Observations and models show that summertime ozone (O3) and aerosol concentrations largely exceed the European Union air quality standards; and may exert a strong influence on the regional climate. The highly urbanized coastal areas exert a strong anthropogenic pressure giving riseâunder strong insolationâto photochemical pollution episodes over the region. A coastline constitutes a step change in all surface parameters, which hampers the performance of air quality forecasts. Barcelona is an urban coastal city located in the Western Mediterranean Basin (WMB). As the mixing height is a key parameter for air quality modeling, the large Barcelona lidar database was analyzed to derive a mixing height climatology over the area. Three methods were tested. Typical summertime layering of aerosols introduces large biases using available methods. A reformulation of the Inflection Point Method with new application criteria improved the accuracy of the retrievals. In summer, mixing heights are mainly limited to 400 - 800 m due to large mesoscale compensatory subsidence over the sea and local thermal internal boundary-layer formation. In a second step photochemical modeling was conducted in the Barcelona geographical area for one episode to study the influence of three surface/PBL schemes (one local and two non-local schemes), on the predicted photochemical pollutant concentrations. Modeled mixing height, temperature, and wind speed and direction were evaluated with lidar and meteorological data in order to analyze the differences observed. Modeled daily maximum pollutantsâ concentrations varied in magnitude and location in function of the PBL scheme and PBL height diagnosis method used in the model. Mainly, the lower mixing heights achieved by the local scheme promoted the highest maximum 1-hr O3 concentration and the lowest maximum 8-hr O3 average concentration during daytime, which improved the statistical scores in comparison to the other schemes. The geomorphological and meteorological characteristics of the Mediterranean basin result in a predominance of mesoscale circulations in the summertime troposphere. Regular lidar measurements showed that local/regional layering is a recurrent pattern in the region. Out of 156 valid measurement days, 67 days presented a multiple-layer structure of aerosols due to vertical re-circulation processes. Aerosol layers were systematically detected above the ML up to 4000 m with variable thickness typically ranged between 100 m and 1000 m. The origin of the upper polluted layers is attributed to the effect of the Iberian Thermal low or to far-traveled aerosols. The main local pathways and injections of the polluted air masses were analyzed through a high resolution meteorological simulation. Concerning the influence of Saharan dust on the regional climate and meteorology, current state-of-the-art is rather unsatisfactory. In fact, dust regional forecast models treat dust as a radiatively passive substance. In this context, the dust radiative effects have been included in the DREAM modeling system. Simulations of a major dust storm in the Mediterranean have shown that this step forward leads to significant improvements on the forecasted atmospheric temperatures and mean sea level pressure over dust-affected areas. Because the vertical structure is essential for the accurate calculation of the radiative fluxes, the predicted extinction profiles were validated with the Raman lidar station in Napoli (Italy). In addition, the dust direct radiative effects on solar and terrestrial wavelengths, the changes produced on surface turbulent fluxes and the feedback on 8 dust em 2e5 ission were explored. The results outline a strong dust negative feedback upon dust emission.

Author: BENEITO SENDRA JORDI.
Year: 2005.
University: BARCELONA [www.ub.es].
Place of defense: FACULTAD DE FÍSICA.
Place of preparation: FACULTAD DE FÍSICA.