Estrategias para la mejora de la calidad del aire en una ciudad: Movilidad y vehículo eléctrico

A pesar de la reducción en la emisión de contaminantes atmosféricos de los últimos años, los niveles de calidad del aire en Europa y España siguen superando los valores límite legislados. Dichas superaciones, debidas principalmente a material particulado y dióxido de nitrógeno, se localizan especialmente en las ciudades, donde la mayor fuente de emisión es el tráfico rodado. Referente a las emisiones de tráfico, en Europa, el incremento de la intensidad de tráfico y la dieselización del parque vehicular, han dificultado la reducción de las emisiones debidas a tráfico, a pesar de la progresiva introducción de estándares de emisión más restrictivos. A nivel Europeo, se está apostando en dos direcciones simultáneamente. Por un lado, la gestión de la movilidad. Y, por el otro, la promoción de los vehículos limpios y energéticamente eficientes mediante dos vías de acción. La primera, la progresiva reducción de las emisiones de los vehículos de combustión interna, gracias a: mejoras tecnológicas y a la introducción de combustibles alternativos. La segunda, la introducción de nuevos sistemas de propulsión, más eficientes y menos contaminantes, cuyo mayor exponente actualmente es el vehículo eléctrico. El presente trabajo hace un repaso al panorama actual de las medidas de reducción de las emisiones de tráfico y su efecto en la calidad del aire. A continuación, se examina el potencial que representa el vehículo eléctrico, el cual presenta dos ventajas en cuanto a reducción de emisiones. La primera es que el vehículo no tiene emisiones de tubo de escape o combustión, con lo que se reducen las emisiones directas en el entorno urbano. No obstante, las emisiones se trasladan a la generación de energía. La segunda ventaja es que la eficiencia energética total (desde la extracción del combustible fósil a la tracción de las ruedas del vehículo), es mayor en los vehículos eléctricos que en los convencionales de combustión, por lo que las emisiones totales también se reducen. Además, si se considera un mix energético basado en energías renovables y/o nuclear, las emisiones son nulas. Los principales retos tecnológicos que presenta la implantación del vehículo eléctrico están relacionados con la integración de las recargas en el sistema eléctrico y la capacidad de las baterías. No obstante, dicha limitación de capacidad hace al vehículo eléctrico estar especialmente indicado para entornos urbanos, caracterizados por desplazamientos cortos. Referente a la gestión de la movilidad, no hay una estrategia única, ya que depende mucho de las características de cada ciudad: composición del parque vehicular, orografía, condiciones meteorológicas, etc. No obstante, las líneas generales apuntan a la disminución de los kilómetros recorridos por: los vehículos más contaminantes y el transporte privado. Dado que ninguna de las medidas planteadas hasta el momento por si sola permite mejorar los niveles de calidad del aire urbano a corto plazo, el objetivo debe ser la introducción de diferentes medidas complementarias. Con ello, se hace necesario el estudio en detalle de cada zona. La Tesis Doctoral se centrará en el análisis mediante herramientas de modelización de las medidas para la mejora de la calidad del aire en las ciudades de Barcelona y Madrid

Characterization of the near surface wind speed distribution at global scale: ERA- Interim reanalysis and ECMWF seasonal forecasting System 4

The present developments in 10 m wind seasonal forecast products have lead to a growth in the number of studies analysing different aspects of both its predictability and applicability. However, there is still a lack of global studies analysing the statistical properties of the probability distribution of 10 m wind speed comparing the seasonal forecast systems with the widely used reanalysis products. To fill this gap we have studied the properties of the probability distributions of 10 m wind speed from the ERA-Interim reanalysis and the European Centre for Medium-Range Weather Forecasts System 4 seasonal forecast system. We have focused on two seasons, JJA and DJF, considering both their interannual and intraseasonal variability. The 10 m wind speed distribution has been characterized in terms of the four main moments of the probability distribution (mean, standard deviation, skewness and kurtosis). We have also computed the coefficient of variation to identify the regions with the higher wind variability and the Shapiro-Wilks goodness of fit test to assess their normality. This set of parameters is important to provide useful climate information in wind energy decision-making processes that use simple assumptions of the wind speed frequency distribution to properly estimate the wind energy potential. Besides, this study also illustrates where the discrepancies of the distributions of the seasonal predictions and the reference dataset are higher and, thus, which might need special attention from a bias adjustment perspective

Potential of TROPOMI for understanding spatio-temporal variations in surface NO2 and their dependencies upon land use over the Iberian Peninsula

In orbit since late 2017, the Tropospheric Monitoring Instrument (TROPOMI) is offering new outstanding opportunities for better understanding the emission and fate of nitrogen dioxide (NO2) pollution in the troposphere. In this study, we provide a comprehensive analysis of the spatio-temporal variability of TROPOMI NO2 tropospheric columns (TrC-NO2) over the Iberian Peninsula during 2018–2021, considering the recently developed Product Algorithm Laboratory (PAL) product. We complement our analysis with estimates of NOx anthropogenic and natural soil emissions. Closely related to cloud cover, the data availability of TROPOMI observations ranges from 30 %–45 % during April and November to 70 %–80 % during summertime, with strong variations between northern and southern Spain. Strongest TrC-NO2 hotspots are located over Madrid and Barcelona, while TrC-NO2 enhancements are also observed along international maritime routes close the strait of Gibraltar, and to a lesser extent along specific major highways. TROPOMI TrC-NO2 appear reasonably well correlated with collocated surface NO2 mixing ratios, with correlations around 0.7–0.8 depending on the averaging time. We investigate the changes of weekly and monthly variability of TROPOMI TrC-NO2 depending on the urban cover fraction. Weekly profiles show a reduction of TrC-NO2 during the weekend ranging from −10 % to −40 % from least to most urbanized areas, in reasonable agreement with surface NO2. In the largest agglomerations like Madrid or Barcelona, this weekend effect peaks not in the city center but in specific suburban areas/cities, suggesting a larger relative contribution of commuting to total NOx anthropogenic emissions. The TROPOMI TrC-NO2 monthly variability also strongly varies with the level of urbanization, with monthly differences relative to annual mean ranging from −40 % in summer to +60 % in winter in the most urbanized areas, and from −10 % to +20 % in the least urbanized areas. When focusing on agricultural areas, TROPOMI observations depict an enhancement in June–July that could come from natural soil NO emissions. Some specific analysis of surface NO2 observations in Madrid show that the relatively sharp NO2 minimum used to occur in August (drop of road transport during holidays) has now evolved into a much broader minimum partly de-coupled from the observed local road traffic counting; this change started in 2018, thus before the COVID-19 outbreak. Over 2019–2021, a reasonable consistency of the inter-annual variability of NO2 is also found between both datasets. Our study illustrates the strong potential of TROPOMI TrC-NO2 observations for complementing the existing surface NO2 monitoring stations, especially in the poorly covered rural and maritime areas where NOx can play a key role, notably for the production of tropospheric O3.We acknowledge the RES (AECT-2022-1- 0008, AECT-2022-2-0003) for awarding us access to the MareNostrum supercomputer in the Barcelona Supercomputing Center, and we also acknowledge the support from the Red Temática ACTRIS España (CGL2017-90884-REDT) and the H2020 ACTRIS IMP (no. 871115). SC acknowledges support from BELSPO through BRAIN-BE 2.0 project LEGO-BEL-AQ (contract B2/191/P1/LEGO-BEL-AQ). This research has received fund- ing from the Ramon y Cajal grant (RYC2021-034511-I, MCIN/AEI/10.13039/501100011033 and European Union NextGenerationEU/PRTR), the MITIGATE (PID2020- 16324RA695 I00/AEI/10.13039/501100011033) and VITALISE (PID2019-108086RA-I00 MCIN/AEI/10.13039/501100011033) projects from the Agencia Estatal de Investigación (AEI), the European Union’s Horizon 2020 research and innovation program under grant agreement no. 870301 (AQ-WATCH H2020 project), and the AXA Research Fund.Peer ReviewedPostprint (published version

To what extent the traffic restriction policies applied in Barcelona city can improve its air quality?

Barcelona city (Spain) is applying a series of traffic restriction measures that aim at renewing and reducing the amount of circulating vehicles to improve air quality. The measures include changes in the built environment to reduce private vehicle space in specific areas through the so-called “superblocks” and tactical urban planning actions, along with the implementation of a city-wide Low Emission Zone (LEZ) that restricts the entry of the most polluting vehicles to the city. Our study quantifies the impact of these measures in the greater area of Barcelona combining a coupled macroscopic traffic and pollutant emission model with a multi-scale air quality model. Our modelling system allows estimating the effect of different traffic restrictions upon traffic and the associated emissions and air quality levels at a very high resolution (20 m). The measures were evaluated both individually and collectively to assess both their relative and overall impact upon emissions and air quality. We show that in the absence of traffic demand reductions, the application of isolated measures that reduce private vehicle space, either through superblocks or tactical urban planning, have no overall emission impacts; only localized street-level NOx positive and negative changes (±17%) are found due to traffic re-routing and the generation of new bottlenecks. It is only when these measures are combined with optimistic fleet renewal as a result of the LEZ implementation and demand reductions, that relevant global emission reductions in NOx are obtained (-13% and -30%, respectively) with estimated NO2 reductions of -36% and -23% at the two traffic air quality monitoring stations. Despite the potential improvements, our simulations suggest that current measures are insufficient to comply with EU air quality standards and that further traffic restriction policies to reduce traffic demand are needed.The authors acknowledge CARNET-The Future Mobility Research HUB to allow the usage and work on the BCN-VML network, as well as PTV VISUM for the traffic software license. The author thankfully acknowledges the computer resources at MareNostrum and the technical support pro- vided by Barcelona Supercomputing Center (PRACE, AECT-2020-1-0007, AECT-2021-1-0027). The authors also acknowledge the support from the Ministerio de Ciencia, Innovación y Universidades (MICINN) as part of the BROWNING project RTI2018-099894-B-I00 and NUTRIENT project CGL2017-88911-R and the support from the Agencia Estatal de Investigacion (AEI) as part of the VITALISE project (PID2019-108086RA- I00/AEI/10.13039/501100011033). Carlos Pérez García-Pando acknowl- edges the long-term support from the AXA Chair in Sand and Dust Storms (AXA Research Fund), as well as the support received through the Ramón y Cajal programme (grant RYC-2015-18690) of the Spanish Ministry of Economy and Competitiveness.Peer ReviewedPostprint (published version

Estrategias para la mejora de la calidad del aire en una ciudad: Movilidad y vehículo eléctrico

A pesar de la reducción en la emisión de contaminantes atmosféricos de los últimos años, los niveles de calidad del aire en Europa y España siguen superando los valores límite legislados. Dichas superaciones, debidas principalmente a material particulado y dióxido de nitrógeno, se localizan especialmente en las ciudades, donde la mayor fuente de emisión es el tráfico rodado. Referente a las emisiones de tráfico, en Europa, el incremento de la intensidad de tráfico y la dieselización del parque vehicular, han dificultado la reducción de las emisiones debidas a tráfico, a pesar de la progresiva introducción de estándares de emisión más restrictivos. A nivel Europeo, se está apostando en dos direcciones simultáneamente. Por un lado, la gestión de la movilidad. Y, por el otro, la promoción de los vehículos limpios y energéticamente eficientes mediante dos vías de acción. La primera, la progresiva reducción de las emisiones de los vehículos de combustión interna, gracias a: mejoras tecnológicas y a la introducción de combustibles alternativos. La segunda, la introducción de nuevos sistemas de propulsión, más eficientes y menos contaminantes, cuyo mayor exponente actualmente es el vehículo eléctrico. El presente trabajo hace un repaso al panorama actual de las medidas de reducción de las emisiones de tráfico y su efecto en la calidad del aire. A continuación, se examina el potencial que representa el vehículo eléctrico, el cual presenta dos ventajas en cuanto a reducción de emisiones. La primera es que el vehículo no tiene emisiones de tubo de escape o combustión, con lo que se reducen las emisiones directas en el entorno urbano. No obstante, las emisiones se trasladan a la generación de energía. La segunda ventaja es que la eficiencia energética total (desde la extracción del combustible fósil a la tracción de las ruedas del vehículo), es mayor en los vehículos eléctricos que en los convencionales de combustión, por lo que las emisiones totales también se reducen. Además, si se considera un mix energético basado en energías renovables y/o nuclear, las emisiones son nulas. Los principales retos tecnológicos que presenta la implantación del vehículo eléctrico están relacionados con la integración de las recargas en el sistema eléctrico y la capacidad de las baterías. No obstante, dicha limitación de capacidad hace al vehículo eléctrico estar especialmente indicado para entornos urbanos, caracterizados por desplazamientos cortos. Referente a la gestión de la movilidad, no hay una estrategia única, ya que depende mucho de las características de cada ciudad: composición del parque vehicular, orografía, condiciones meteorológicas, etc. No obstante, las líneas generales apuntan a la disminución de los kilómetros recorridos por: los vehículos más contaminantes y el transporte privado. Dado que ninguna de las medidas planteadas hasta el momento por si sola permite mejorar los niveles de calidad del aire urbano a corto plazo, el objetivo debe ser la introducción de diferentes medidas complementarias. Con ello, se hace necesario el estudio en detalle de cada zona. La Tesis Doctoral se centrará en el análisis mediante herramientas de modelización de las medidas para la mejora de la calidad del aire en las ciudades de Barcelona y Madrid

The Potential impacts of electric vehicles on air quality in the urban areas of Barcelona and Madrid (Spain)

This work analyses the potential air quality improvements resulting from three fleet electrification scenarios (similar to 13, 26 and 40%) by replacing conventional vehicles with Electric Battery Vehicles (EBVs), Plug-in Hybrid Electric Vehicles (PHEVs) and Hybrid Electric Vehicles (HEVs). This study has been performed for the cities of Barcelona and Madrid (Spain), where road transport is the primary emission source. In these urban areas, several air quality problems are present, mainly related to NO2 and particulate matter. The WRF-ARW/HERMESv2/CMAQ model system has been applied at high spatial (1 x 1 km(2)) and temporal (1 h) resolution. The results show that fleet electrification offers a potential for emission abatement, especially related to NO and CO. Regarding the more ambitious scenario (similar to 40% fleet electrification), reductions of 11% and 17% of the total NOx emissions are observed in Barcelona and Madrid respectively. These emissions reductions involve air quality improvements in NO2 maximum hourly values up to 16%: reductions up to 30 and 35 mu g m(-3) in Barcelona and Madrid, respectively. Furthermore, an additional scenario has been defined considering electric generation emissions associated with EBVs and PHEVs charging from a combined-cycle power plant. These charging emissions would produce slight NO2 increases in the downwind areas of <3 mu g m(-3). Thus, fleet electrification would improve urban air quality even when considering emissions associated with charging electric vehicles. However, two further points should be considered. First, fleet electrification cannot be considered a unique solution, and other management strategies may be defined. This is especially important with respect to particulate matter emissions, which are not significantly reduced by fleet electrification (<5%) due to the high weight of non-exhaust emissions. Second, a significant introduction of electric vehicles (26-40%) involving all vehicle categories is required to improve urban air quality. (C) 2014 Elsevier Ltd. All rights reserved.Postprint (published version

The Potential impacts of electric vehicles on air quality in the urban areas of Barcelona and Madrid (Spain)

This work analyses the potential air quality improvements resulting from three fleet electrification scenarios (similar to 13, 26 and 40%) by replacing conventional vehicles with Electric Battery Vehicles (EBVs), Plug-in Hybrid Electric Vehicles (PHEVs) and Hybrid Electric Vehicles (HEVs). This study has been performed for the cities of Barcelona and Madrid (Spain), where road transport is the primary emission source. In these urban areas, several air quality problems are present, mainly related to NO2 and particulate matter. The WRF-ARW/HERMESv2/CMAQ model system has been applied at high spatial (1 x 1 km(2)) and temporal (1 h) resolution. The results show that fleet electrification offers a potential for emission abatement, especially related to NO and CO. Regarding the more ambitious scenario (similar to 40% fleet electrification), reductions of 11% and 17% of the total NOx emissions are observed in Barcelona and Madrid respectively. These emissions reductions involve air quality improvements in NO2 maximum hourly values up to 16%: reductions up to 30 and 35 mu g m(-3) in Barcelona and Madrid, respectively. Furthermore, an additional scenario has been defined considering electric generation emissions associated with EBVs and PHEVs charging from a combined-cycle power plant. These charging emissions would produce slight NO2 increases in the downwind areas of <3 mu g m(-3). Thus, fleet electrification would improve urban air quality even when considering emissions associated with charging electric vehicles. However, two further points should be considered. First, fleet electrification cannot be considered a unique solution, and other management strategies may be defined. This is especially important with respect to particulate matter emissions, which are not significantly reduced by fleet electrification (<5%) due to the high weight of non-exhaust emissions. Second, a significant introduction of electric vehicles (26-40%) involving all vehicle categories is required to improve urban air quality. (C) 2014 Elsevier Ltd. All rights reserved

Integrated assessment of air pollution using observations and modelling in Santa Cruz de Tenerife (Canary Islands)

The present study aims to analyse the atmospheric dynamics of the Santa Cruz de Tenerife region (Tenerife, Canary Islands). This area is defined by the presence of anthropogenic emissions (from a refinery, a port and road traffic) and by very specific meteorological and orographic conditions-it is a coastal area with a complex topography in which there is an interaction of regional atmospheric dynamics and a low thermal inversion layer. These factors lead to specific atmospheric pollution episodes, particularly in relation to SO2 and PM10. We applied a methodology to study these dynamics based on two complementary approaches: 1) the analysis of the observations from the air quality network stations and 2) simulation of atmospheric dynamics using the WRF-ARW/HERMESv2/CMAQ/BSC-DREAM8b and WRF-ARW/HYSPLIT modelling systems with a high spatial resolution (1×1km2). The results of our study show that the refinery plume plays an important role in the maximum SO2 observed levels. The area of maximum impact of the refinery is confined to a radius of 3km around this installation. A cluster analysis performed for the period: 1998-2011 identified six synoptic situations as predominant in the area. The episodes of air pollution by SO2 occur mainly in those with more limited dispersive conditions, such as the northeastern recirculation, the northwestern recirculation and the western advection, which represent 33.70%, 11.23% and 18.63% of the meteorological situations affecting the study area in the year 2011, respectively. In the case of particulate matter, Saharan dust intrusions result in episodes with high levels of PM10 that may exceed the daily limit value in all measurement station; these episodes occur when the synoptic situation is from the east (3.29% of the situations during the year 2011). © 2013 Elsevier B.V

The elastic-plastic behaviour of semi-rigid connections in steel structures

SIGLEAvailable from British Library Lending Division - LD:D57633/85 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Integrated assessment of air pollution using observations and modelling in Santa Cruz de Tenerife (Canary Islands)

The present study aims to analyse the atmospheric dynamics of the Santa Cruz de Tenerife region (Tenerife, Canary Islands). This area is defined by the presence of anthropogenic emissions (from a refinery, a port and road traffic) and by very specific meteorological and orographic conditions-it is a coastal area with a complex topography in which there is an interaction of regional atmospheric dynamics and a low thermal inversion layer. These factors lead to specific atmospheric pollution episodes, particularly in relation to SO2 and PM10. We applied a methodology to study these dynamics based on two complementary approaches: 1) the analysis of the observations from the air quality network stations and 2) simulation of atmospheric dynamics using the WRF-ARW/HERMESv2/CMAQ/BSC-DREAM8b and WRF-ARW/HYSPLIT modelling systems with a high spatial resolution (1×1km2). The results of our study show that the refinery plume plays an important role in the maximum SO2 observed levels. The area of maximum impact of the refinery is confined to a radius of 3km around this installation. A cluster analysis performed for the period: 1998-2011 identified six synoptic situations as predominant in the area. The episodes of air pollution by SO2 occur mainly in those with more limited dispersive conditions, such as the northeastern recirculation, the northwestern recirculation and the western advection, which represent 33.70%, 11.23% and 18.63% of the meteorological situations affecting the study area in the year 2011, respectively. In the case of particulate matter, Saharan dust intrusions result in episodes with high levels of PM10 that may exceed the daily limit value in all measurement station; these episodes occur when the synoptic situation is from the east (3.29% of the situations during the year 2011). © 2013 Elsevier B.V