scholarly journals Trends of Rural Tropospheric Ozone at the Northwest of the Iberian Peninsula

2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
S. Saavedra ◽  
A. Rodríguez ◽  
J. A. Souto ◽  
J. J. Casares ◽  
J. L. Bermúdez ◽  
...  
Keyword(s):  
Air Quality ◽  
Iberian Peninsula ◽  
Tropospheric Ozone ◽  
Air Quality Measurements ◽  
Meteorological Influences ◽  
Emission Changes ◽  
Rural Sites ◽  
Rural Character ◽  
Ozone Episodes ◽  
Ozone Levels

Tropospheric ozone levels around urban and suburban areas at Europe and North America had increased during 80’s–90’s, until the application of NOxreduction strategies. However, as it was expected, this ozone depletion was not proportional to the emissions reduction. On the other hand, rural ozone levels show different trends, with peaks reduction and average increments; this different evolution could be explained by either emission changes or climate variability in a region. In this work, trends of tropospheric ozone episodes at rural sites in the northwest of the Iberian Peninsula were analyzed and compared to others observed in different regions of the Atlantic European coast. Special interest was focused on the air quality sites characterization, in order to guarantee their rural character in terms of air quality. Both episodic local meteorological and air quality measurements along five years were considered, in order to study possible meteorological influences in ozone levels, different to other European Atlantic regions.

scholarly journals Seasonal Simulation of Tropospheric Ozone over the Midwestern and Northeastern United States: An Application of a Coupled Regional Climate and Air Quality Modeling System

2007 ◽  
Vol 46 (7) ◽  
pp. 945-960 ◽  
Author(s):  
Ho-Chun Huang ◽  
Xin-Zhong Liang ◽  
Kenneth E. Kunkel ◽  
Michael Caughey ◽  
Allen Williams
Keyword(s):  
United States ◽  
Air Quality ◽  
Tropospheric Ozone ◽  
General Circulation ◽  
Climate Model ◽  
Regional Climate ◽  
Future Climate ◽  
Climate Projections ◽  
Northeastern United States ◽  
Ozone Episodes

Abstract The impacts of air pollution on the environment and human health could increase as a result of potential climate change. To assess such possible changes, model simulations of pollutant concentrations need to be performed at climatic (seasonal) rather than episodic (days) time scales, using future climate projections from a general circulation model. Such a modeling system was employed here, consisting of a regional climate model (RCM), an emissions model, and an air quality model. To assess overall model performance with one-way coupling, this system was used to simulate tropospheric ozone concentrations in the midwestern and northeastern United States for summer seasons between 1995 and 2000. The RCM meteorological conditions were driven by the National Centers for Environmental Prediction/Department of Energy global reanalysis (R-2) using the same procedure that integrates future climate model projections. Based on analyses for several urban and rural areas and regional domains, fairly good agreement with observations was found for the diurnal cycle and for several multiday periods of high ozone episodes. Even better agreement occurred between monthly and seasonal mean quantities of observed and model-simulated values. This is consistent with an RCM designed primarily to produce good simulations of monthly and seasonal mean statistics of weather systems.

scholarly journals Caliope: an operational air quality forecasting system for the Iberian Peninsula, Balearic Islands and Canary Islands – first annual evaluation and ongoing developments

2008 ◽  
Vol 2 (1) ◽  
pp. 89-98 ◽  
Author(s):  
J. M. Baldasano ◽  
P. Jiménez-Guerrero ◽  
O. Jorba ◽  
C. Pérez ◽  
E. López ◽  
...  
Keyword(s):  
Air Quality ◽  
Iberian Peninsula ◽  
Ground Level ◽  
Present Contribution ◽  
Ground Level Ozone ◽  
Gross Error ◽  
Quantitative Verification ◽  
Forecasting System ◽  
Ozone Episodes ◽  
Air Quality Forecasting

Abstract. The Caliope project funded by the Spanish Ministry of the Environment establishes an air quality forecasting system for Spain to increase the knowledge on transport and dynamics of pollutants in Spain, to assure the accomplishment of legislation and to inform the population about the levels of pollutants, topics in which the European Commission has shown a great concern. The present contribution describes the first quantitative verification study performed so far with two chemistry transport models (CMAQ and CHIMERE) for a reference year (2004) at medium spatial resolution (around 20×20 km for the Iberian Peninsula). Both models perform similarly in the case of ground-level ozone. The mean normalised gross error MNGE remains below 15–20% during summertime, when ozone episodes occur, outlining the good skills of the system concerning the forecasting of air quality in Spain. Furthermore, the ongoing developments of the system towards high resolution modelling (4×4 km for Spain, 12×12 km for Europe, 1 h temporal resolution) and the integration with observations within the Caliope umbrella are described.

scholarly journals Assessment of parameters describing representativeness of air quality in-situ measurement sites

2009 ◽  
Vol 9 (5) ◽  
pp. 20019-20062 ◽  
Author(s):  
S. Henne ◽  
D. Brunner ◽  
D. Folini ◽  
S. Solberg ◽  
J. Klausen ◽  
...  
Keyword(s):  
Air Quality ◽  
Particle Dispersion ◽  
Surface Fluxes ◽  
Wind Fields ◽  
Mixing Ratios ◽  
Air Quality Measurements ◽  
Novel Approach ◽  
Variable Surface ◽  
Catchment Areas ◽  
Rural Sites

Abstract. The atmospheric layer closest to the ground is strongly influenced by variable surface fluxes (emissions, surface deposition) and can therefore be very heterogeneous. In order to perform air quality measurements that are representative of a larger domain or a certain degree of pollution, observatories are placed away from population centres or within areas of specific population density. Sites are often categorised based on subjective criteria that are not uniformly applied within different administrative domains. A novel approach for the assessment of parameters reflecting site representativeness is presented here, taking emissions, deposition and transport towards 34 sites covering Western and Central Europe into account. These parameters are directly inter-comparable among the sites and can be used to select sites that are, on average, more or less suitable for data assimilation and comparison with satellite and model data. Advection towards these sites was simulated by backward Lagrangian Particle Dispersion Modelling (LPDM) to determine the sites' annual catchment areas for the year 2005 and advection times of 12, 24 and 48 h. Only variations caused by emissions and transport during these periods were considered assuming that these dominate the short-term variability of most but especially short lived trace gases. The parameters of representativeness derived were compared between sites and a novel, uniform and observation-independent categorisation of the sites based on a clustering approach was established. Six groups of European background sites were identified ranging from very remote coastal to polluted rural sites. These six categories explained 50 to 80% of the inter-site variability of median mixing ratios and their standard deviation for NO2 and O3, while differences between group means of the longer lived trace gas CO were insignificant. The derived annual catchment areas strongly depended on the applied LPDM and input wind fields, the catchment settings and the year of analysis. Nevertheless, the parameters of representativeness showed considerably less variability than the catchment geometry, supporting the robustness of the derived station categorisation.

scholarly journals The impact of measures to reduce ambient air PM<sub>10</sub> concentrations originating from road dust, evaluated for a street canyon in Helsinki

2019 ◽  
Vol 19 (17) ◽  
pp. 11199-11212 ◽  
Author(s):  
Ana Stojiljkovic ◽  
Mari Kauhaniemi ◽  
Jaakko Kukkonen ◽  
Kaarle Kupiainen ◽  
Ari Karppinen ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Air Quality ◽  
Street Canyon ◽  
Dust Emission ◽  
Road Dust ◽  
Ambient Air ◽  
Air Quality Measurements ◽  
Emission Models ◽  
The Impact ◽  
Quality Measurements

Abstract. We have numerically evaluated how effective selected potential measures would be for reducing the impact of road dust on ambient air particulate matter (PM10). The selected measures included a reduction of the use of studded tyres on light-duty vehicles and a reduction of the use of salt or sand for traction control. We have evaluated these measures for a street canyon located in central Helsinki for four years (2007–2009 and 2014). Air quality measurements were conducted in the street canyon for two years, 2009 and 2014. Two road dust emission models, NORTRIP (NOn-exhaust Road TRaffic Induced Particle emissions) and FORE (Forecasting Of Road dust Emissions), were applied in combination with the Operational Street Pollution Model (OSPM), a street canyon dispersion model, to compute the street increments of PM10 (i.e. the fraction of PM10 concentration originating from traffic emissions at the street level) within the street canyon. The predicted concentrations were compared with the air quality measurements. Both road dust emission models reproduced the seasonal variability of the PM10 concentrations fairly well but under-predicted the annual mean values. It was found that the largest reductions of concentrations could potentially be achieved by reducing the fraction of vehicles that use studded tyres. For instance, a 30 % decrease in the number of vehicles using studded tyres would result in an average decrease in the non-exhaust street increment of PM10 from 10 % to 22 %, depending on the model used and the year considered. Modelled contributions of traction sand and salt to the annual mean non-exhaust street increment of PM10 ranged from 4 % to 20 % for the traction sand and from 0.1 % to 4 % for the traction salt. The results presented here can be used to support the development of optimal strategies for reducing high springtime particulate matter concentrations originating from road dust.

scholarly journals Abrupt but smaller than expected changes in surface air quality attributable to COVID-19 lockdowns

2021 ◽  
Vol 7 (3) ◽  
pp. eabd6696
Author(s):  
Zongbo Shi ◽  
Congbo Song ◽  
Bowen Liu ◽  
Gongda Lu ◽  
Jingsha Xu ◽  
...  
Keyword(s):  
Air Quality ◽  
Air Pollutant ◽  
Pollutant Emissions ◽  
Quality Improvements ◽  
Learning Technique ◽  
Emission Changes ◽  
Almost All ◽  
Gaseous Oxidant ◽  
Sophisticated Analysis ◽  
Limited Change

The COVID-19 lockdowns led to major reductions in air pollutant emissions. Here, we quantitatively evaluate changes in ambient NO2, O3, and PM2.5 concentrations arising from these emission changes in 11 cities globally by applying a deweathering machine learning technique. Sudden decreases in deweathered NO2 concentrations and increases in O3 were observed in almost all cities. However, the decline in NO2 concentrations attributable to the lockdowns was not as large as expected, at reductions of 10 to 50%. Accordingly, O3 increased by 2 to 30% (except for London), the total gaseous oxidant (Ox = NO2 + O3) showed limited change, and PM2.5 concentrations decreased in most cities studied but increased in London and Paris. Our results demonstrate the need for a sophisticated analysis to quantify air quality impacts of interventions and indicate that true air quality improvements were notably more limited than some earlier reports or observational data suggested.

scholarly journals Context aware benchmarking and tuning of a TByte-scale air quality database and web service

2021 ◽  
Author(s):  
Clara Betancourt ◽  
Björn Hagemeier ◽  
Sabine Schröder ◽  
Martin G. Schultz
Keyword(s):  
Air Quality ◽  
Web Service ◽  
Statistical Processing ◽  
Quality Metrics ◽  
Context Aware ◽  
Near Surface ◽  
On Demand ◽  
Air Quality Measurements ◽  
Present Context ◽  
And Performance

AbstractWe present context-aware benchmarking and performance engineering of a mature TByte-scale air quality database system which was created by the Tropospheric Ozone Assessment Report (TOAR) and contains one of the world’s largest collections of near-surface air quality measurements. A special feature of our data service https://join.fz-juelich.de is on-demand processing of several air quality metrics directly from the TOAR database. As a service that is used by more than 350 users of the international air quality research community, our web service must be easily accessible and functionally flexible, while delivering good performance. The current on-demand calculations of air quality metrics outside the database together with the necessary transfer of large volume raw data are identified as the major performance bottleneck. In this study, we therefore explore and benchmark in-database approaches for the statistical processing, which results in performance enhancements of up to 32%.

scholarly journals An Overview of Small Unmanned Aerial Vehicles for Air Quality Measurements: Present Applications and Future Prospectives

Sensors ◽  
2016 ◽  
Vol 16 (7) ◽  
pp. 1072 ◽  
Author(s):  
Tommaso Villa ◽  
Felipe Gonzalez ◽  
Branka Miljievic ◽  
Zoran Ristovski ◽  
Lidia Morawska
Keyword(s):  
Air Quality ◽  
Unmanned Aerial Vehicles ◽  
Aerial Vehicles ◽  
Air Quality Measurements ◽  
Quality Measurements
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