The Impact of Meteorology on Air Quality Simulations over the Po Valley in Northern Italy

2011 ◽  
pp. 485-490 ◽  
Author(s):  
Denise Pernigotti ◽  
Emilia Georgieva ◽  
Philippe Thunis ◽  
Cornelius Cuvelier ◽  
Alexander de Meij
Keyword(s):  
Air Quality ◽  
Northern Italy ◽  
Po Valley ◽  
The Impact

scholarly journals Improving Air Quality in the Po Valley, Italy: Some Results by the LIFE-IP-PREPAIR Project

Atmosphere ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 429 ◽  
Author(s):  
Katia Raffaelli ◽  
Marco Deserti ◽  
Michele Stortini ◽  
Roberta Amorati ◽  
Matteo Vasconi ◽  
...  
Keyword(s):  
Air Quality ◽  
Northern Italy ◽  
The European Union ◽  
Limit Values ◽  
Po Valley ◽  
Limit Value ◽  
Northern Regions ◽  
Environmental Agencies ◽  
The Impact ◽  
The Eu

The Po Valley (Northern Italy) represents an important exceedance zone of the air-quality limit values for PM (particulate matter), NO2 (nitrogen dioxide) and O3 (ozone). This area covers the territory of most Italian northern regions and includes several urban agglomerates, such as Milan, Turin, Venice and Bologna. The area is densely populated and heavily industrialized. The paper summarizes the assessment of the impact of the current (2013) and future (2025) emissions and of the meteorological conditions on the air quality of the Po Valley. This study is one of the first outcomes of the EU LIFE-IP Clean Air Program Po Regions Engaged to Policies of Air (PREPAIR) project. The project, involving administrations and environmental agencies of eight regions and three municipalities in Northern Italy and Slovenia, started in 2017 and will end in 2024. Future emission scenarios consider the emissions reduction due to the air-quality action plans of the regions involved, of the agreements between the national authorities and regional administrations and of the PREPAIR project itself, in the overall context of the application of the current legislation of the European Union. The combination of these measures will lead to the reduction of direct emissions of PM10 in the Po Valley and of the main precursors emitted in the area (NOx, nitrogen oxides and NH3, and ammonia) by 38% for PM10, 39% for NOx and 22% for NH3, respectively. This lowering corresponds to a reduction of about 30.000 tons of primary PM10, 150.000 tons of NOx, 54.000 tons of NH3 and 1700 tons of SO2. The results show that these expected reductions should allow us to achieve the EU PM10 limit value in the Po Valley by the year 2025.

scholarly journals Regional Scale Impact of the COVID-19 Lockdown on Air Quality: Gaseous Pollutants in the Po Valley, Northern Italy

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 264 ◽  
Author(s):  
Giovanni Lonati ◽  
Federico Riva
Keyword(s):  
Air Quality ◽  
Urban Areas ◽  
Regional Scale ◽  
High Volume ◽  
Ambient Air ◽  
Northern Italy ◽  
Traffic Emissions ◽  
Gaseous Pollutants ◽  
Po Valley ◽  
Concentration Levels

The impact of the reduced atmospheric emissions due to the COVID-19 lockdown on ambient air quality in the Po Valley of Northern Italy was assessed for gaseous pollutants (NO2, benzene, ammonia) based on data collected at the monitoring stations distributed all over the area. Concentration data for each month of the first semester of 2020 were compared with those of the previous six years, on monthly, daily, and hourly bases, so that pre, during, and post-lockdown conditions of air quality could be separately analyzed. The results show that, as in many other areas worldwide, the Po Valley experienced better air quality during 2020 spring months for NO2 and benzene. In agreement with the reductions of nitrogen oxides and benzene emissions from road traffic, estimated to be −35% compared to the regional average, the monthly mean concentration levels for 2020 showed reductions in the −40% to −35% range compared with the previous years, but with higher reductions, close to −50%, at high-volume-traffic sites in urban areas. Conversely, NH3 ambient concentration levels, almost entirely due the emissions of the agricultural sector, did not show any relevant change, even at high-volume-traffic sites in urban areas. These results point out the important role of traffic emissions in NO2 and benzene ambient levels in the Po Valley, and confirm that this region is a rather homogeneous air basin with urban area hot-spots, the contributions of which add up to a relatively high regional background concentration level. Additionally, the relatively slow response of the air quality levels to the sudden decrease of the emissions due to the lockdown shows that this region is characterized by a weak exchange of the air masses that favors both the build-up of atmospheric pollutants and the development of secondary formation processes. Thus, air quality control strategies should aim for structural interventions intended to reduce traffic emissions at the regional scale and not only in the largest urban areas.

scholarly journals Transport of Po Valley aerosol pollution to the northwestern Alps – Part 2: Long-term impact on air quality

2019 ◽  
Author(s):  
Henri Diémoz ◽  
Gian Paolo Gobbi ◽  
Tiziana Magri ◽  
Giordano Pession ◽  
Sara Pittavino ◽  
...  
Keyword(s):  
Air Quality ◽  
Chemical Composition ◽  
Weather Prediction ◽  
Urban Site ◽  
Aerosol Layer ◽  
Aerosol Transport ◽  
Po Valley ◽  
Aerosol Mass Concentration ◽  
The Impact ◽  
Aerosol Properties

Abstract. This work evaluates the impact of trans-regional aerosol transport from the polluted Po basin on particulate matter levels (PM10) and physico-chemical characteristics in the northwestern Alps. To this purpose, we exploited a multi-sensor, multiplatform database over a 3-years period (2015–2017) accompanied by a series of numerical simulations. The experimental setup included operational (24/7) vertically-resolved aerosol profiles by an Automated LiDAR-Ceilometer (ALC), verticallyintegrated aerosol properties by a sun/sky photometer, and surface measurements of aerosol mass concentration, size distribution and chemical composition. This experimental set of observations was then complemented by modelling tools, including Numerical Weather Prediction (NWP), Trajectory Statistical (TSM) and Chemical Transport (CTM) models, plus Positive Matrix Factorisation (PMF) on both the PM10 chemical speciation analyses and size distributions. In a first companion study (Diémoz et al., 2019), we showed and discussed through detailed case studies the 4-D phenomenology of recurrent episodes of aerosol transport from the polluted Po basin to the northwestern Italian Alps, and particularly to the Aosta Valley. Here we draw more general and statistically significant conclusions on the frequency of occurrence of this phenomenon, and on the quantitative impact of this regular, wind-driven, aerosol-rich atmospheric tide on PM10 air quality levels in this alpine environment. Combining vertically-resolved ALC measurements with wind information, we found that an advected aerosol layer is observed at the receptor site (Aosta) in 93 % of days characterized by easterly winds (thermally-driven winds from the plain or synoptic circulation regimes), and that the longer the time spent by air masses over the Po plain the higher this probability. On a seasonal basis, frequency of advected aerosol layers from the Po basin maximises in summer (70 % of the days classified using the ALC profiles) and minimises in winter and spring (57 % of the classified days). Duration of these advection events ranges from few hours up to several days, while aerosol layer thickness ranges from 500 up to 4000 m. This phenomenon was found to largely impact both surface levels and column-integrated aerosol properties, with PM10 and AOD values respectively increasing up to a factor of 3.5 and 4 in dates under the Po Valley influence. Similar variations in PM10 values observed at different stations within the Aosta Valley also indicated the phenomenon to act at the regional scale and to be related to non-local emissions. Pollution transport events were also shown to modify the mean chemical composition and typical size of particles in the target region. In fact, increase in secondary species, and mainly nitrate- and sulfate-rich components, were found to be effective proxies of the advections, with the transported aerosol responsible for at least 25 % of the PM10 measured in the urban site of Aosta, and adding up to over 50 μg m−3 during specific episodes, thus exceeding alone the EU established daily limit. This percentage is expected to be higher in the rural, pristine areas on the northwestern Alps, where chemical data were not available and trans-boundary contribution to PM10 might thus exceed the local one. Advected aerosols were also found to be on average finer, more light-scattering and more hygroscopic than the locally-produced ones. From a modelling point of view, our CTM simulations performed over a full year showed that the model is able to reproduce the phenomenon but underestimates its impact on PM10 levels. As a sensitivity test, we employed the ALC-derived identification of aerosol advections to re-weight the emissions from outside the boundaries of the regional domain in order to match the observed PM10 field. This simplified exercise indicated that an increase of such external emissions by a factor of 4 in the model would reduce the PM10 mean bias forecasts error (MBE) from −10 μg m−3 to less than 2 μg m−3, the normalised mean standard deviation (NMSD) from over −50 % to less than −10 % and would halve the model PM10 maximum deviations.

Impact of meteorological modelling on air quality: summer and winter episodes in the Po valley (Northern Italy)

2012 ◽  
Vol 50 (1/2/3/4) ◽  
pp. 111 ◽  
Author(s):  
Denise Pernigotti ◽  
Emilia Georgieva ◽  
Philippe Thunis ◽  
Bertrand Bessagnet
Keyword(s):  
Air Quality ◽  
Northern Italy ◽  
Po Valley ◽  
Meteorological Modelling

Impact of meteorology on air quality modeling over the Po valley in northern Italy

2012 ◽  
Vol 51 ◽  
pp. 303-310 ◽  
Author(s):  
D. Pernigotti ◽  
E. Georgieva ◽  
P. Thunis ◽  
B. Bessagnet
Keyword(s):  
Air Quality ◽  
Air Quality Modeling ◽  
Northern Italy ◽  
Po Valley ◽  
Quality Modeling

scholarly journals Transport of Po Valley aerosol pollution to the northwestern Alps – Part 2: Long-term impact on air quality

2019 ◽  
Vol 19 (15) ◽  
pp. 10129-10160 ◽  
Author(s):  
Henri Diémoz ◽  
Gian Paolo Gobbi ◽  
Tiziana Magri ◽  
Giordano Pession ◽  
Sara Pittavino ◽  
...  
Keyword(s):  
Air Quality ◽  
Chemical Composition ◽  
Weather Prediction ◽  
Urban Site ◽  
Aerosol Layer ◽  
Aerosol Transport ◽  
Po Valley ◽  
Aerosol Mass Concentration ◽  
The Impact ◽  
Aerosol Properties

Abstract. This work evaluates the impact of trans-regional aerosol transport from the Po basin on particulate matter levels (PM10) and physico-chemical characteristics in the northwestern Alps. To this purpose, we exploited a multi-sensor, multi-platform database over a 3-year period (2015–2017) accompanied by a series of numerical simulations. The experimental setup included operational (24/7) vertically resolved aerosol profiles by an automated lidar ceilometer (ALC), vertically integrated aerosol properties by a Sun/sky photometer, and surface measurements of aerosol mass concentration, size distribution and chemical composition. This experimental set of observations was then complemented by modelling tools, including numerical weather prediction (NWP), trajectory statistical (TSM) and chemical transport (CTM) models, plus positive matrix factorisation (PMF) on both the PM10 chemical speciation analyses and particle size distributions. In a first companion study, we showed and discussed through detailed case studies the 4-D phenomenology of recurrent episodes of aerosol transport from the polluted Po basin to the northwestern Italian Alps. Here we draw more general and statistically significant conclusions on the frequency of occurrence of this phenomenon, and on the quantitative impact of this regular, wind-driven, aerosol-rich “atmospheric tide” on PM10 air-quality levels in this alpine environment. Based on an original ALC-derived classification, we found that an advected aerosol layer is observed at the receptor site (Aosta) in 93 % of days characterized by easterly winds (i.e. from the Po basin) and that the longer the time spent by air masses over the Po plain the higher this probability. Frequency of these advected aerosol layers was found to be rather stable over the seasons with about 50 % of the days affected. Duration of these advection events ranges from few hours up to several days, while aerosol layer thickness ranges from 500 up to 4000 m. Our results confirm this phenomenon to be related to non-local emissions, to act at the regional scale and to largely impact both surface levels and column-integrated aerosol properties. In Aosta, PM10 and aerosol optical depth (AOD) values increase respectively up to factors of 3.5 and 4 in dates under the Po Valley influence. Pollution transport events were also shown to modify the mean chemical composition and typical size of particles in the target region. In fact, increase in secondary species, and mainly nitrate- and sulfate-rich components, were found to be effective proxies of the advections, with the transported aerosol responsible for at least 25 % of the PM10 measured in the urban site of Aosta, and adding up to over 50 µg m−3 during specific episodes, thus exceeding alone the EU established daily limit. From a modelling point of view, our CTM simulations performed over a full year showed that the model is able to reproduce the phenomenon, but markedly underestimates its impact on PM10 levels. As a sensitivity test, we employed the ALC-derived identification of aerosol advections to re-weight the emissions from outside the boundaries of the regional domain in order to match the observed PM10 field. This simplified exercise indicated that an increase in such “external” emissions by a factor of 4 in the model is needed to halve the model PM10 maximum deviations and to significantly reduce the PM10 normalised mean bias forecasts error (from −35 % to 5 %).

scholarly journals Trends and variability of atmospheric PM<sub>2.5</sub> and PM<sub>10−2.5</sub> concentration in the Po Valley, Italy

2016 ◽  
Author(s):  
Alessandro Bigi ◽  
Grazia Ghermandi
Keyword(s):  
Air Quality ◽  
Hierarchical Cluster ◽  
Atmospheric Pollutants ◽  
Anthropogenic Emissions ◽  
High Concentration ◽  
Atmospheric Concentration ◽  
Po Valley ◽  
Inorganic Aerosols ◽  
Main Components ◽  
The Impact

Abstract. The Po Valley is one of the largest European regions with remarkably high concentration level of atmospheric pollutants, both for particulate and gaseous compounds. In the last decade stringent regulations on air quality standards and on anthropogenic emissions have been set by the European Commission, including also for PM2.5 and its main components since 2008. These regulations lead to an overall improvement on air quality across Europe, including the Po valley and specifically PM10, as shown in a previous study by Bigi and Ghermandi (2014). In order to assess the trend and variability in PM2.5 in the Po valley and its role in the decrease in PM10, we analysed daily gravimetric equivalent concentration of PM2.5 and of PM10−2.5 at 44 and 15 sites respectively across the Po valley. For both PM sizes, the trend in deseasonalized monthly means, annual quantiles and in monthly frequency distribution has been estimated: these showed a significant decreasing trend at several sites for both size fractions and mostly occurring in winter. All series have been tested for a significant weekly periodicity (a proxy to estimate the impact of primary anthropogenic emissions), yielding positive results for summer PM2.5 and for summer and winter PM10−2.5. Hierarchical cluster analysis showed moderate variability in PM2.5 across the valley, with 2 to 3 main clusters, dividing the area in Western, Eastern and Southern/Apennines foothill sectors. The trend in atmospheric concentration was compared with the time series of local emissions, vehicular fleet details and fuel sales, suggesting that the decrease in PM2.5 and in PM10 originates from a drop both in primary and in precursors of Secondary Inorganic Aerosols emissions, largely ascribed to vehicular traffic. Potentially, the increase in biomass burning emissions in winter and the modest decrease in NH3 weaken an otherwise even larger drop in atmospheric concentrations.

scholarly journals Using statistical models to explore ensemble uncertainty in climate impact studies: the example of air pollution in Europe

2016 ◽  
Vol 16 (4) ◽  
pp. 2559-2574 ◽  
Author(s):  
Vincent E. P. Lemaire ◽  
Augustin Colette ◽  
Laurent Menut
Keyword(s):  
Climate Change ◽  
Air Pollution ◽  
Air Quality ◽  
Statistical Model ◽  
Eastern Europe ◽  
Statistical Models ◽  
Regional Climate ◽  
Northern Italy ◽  
Climate Projections ◽  
The Impact

Abstract. Because of its sensitivity to unfavorable weather patterns, air pollution is sensitive to climate change so that, in the future, a climate penalty could jeopardize the expected efficiency of air pollution mitigation measures. A common method to assess the impact of climate on air quality consists in implementing chemistry-transport models forced by climate projections. However, the computing cost of such methods requires optimizing ensemble exploration techniques. By using a training data set from a deterministic projection of climate and air quality over Europe, we identified the main meteorological drivers of air quality for eight regions in Europe and developed statistical models that could be used to predict air pollutant concentrations. The evolution of the key climate variables driving either particulate or gaseous pollution allows selecting the members of the EuroCordex ensemble of regional climate projections that should be used in priority for future air quality projections (CanESM2/RCA4; CNRM-CM5-LR/RCA4 and CSIRO-Mk3-6-0/RCA4 and MPI-ESM-LR/CCLM following the EuroCordex terminology). After having tested the validity of the statistical model in predictive mode, we can provide ranges of uncertainty attributed to the spread of the regional climate projection ensemble by the end of the century (2071–2100) for the RCP8.5. In the three regions where the statistical model of the impact of climate change on PM2.5 offers satisfactory performances, we find a climate benefit (a decrease of PM2.5 concentrations under future climate) of −1.08 (±0.21), −1.03 (±0.32), −0.83 (±0.14) µg m−3, for respectively Eastern Europe, Mid-Europe and Northern Italy. In the British-Irish Isles, Scandinavia, France, the Iberian Peninsula and the Mediterranean, the statistical model is not considered skillful enough to draw any conclusion for PM2.5. In Eastern Europe, France, the Iberian Peninsula, Mid-Europe and Northern Italy, the statistical model of the impact of climate change on ozone was considered satisfactory and it confirms the climate penalty bearing upon ozone of 10.51 (±3.06), 11.70 (±3.63), 11.53 (±1.55), 9.86 (±4.41), 4.82 (±1.79) µg m−3, respectively. In the British-Irish Isles, Scandinavia and the Mediterranean, the skill of the statistical model was not considered robust enough to draw any conclusion for ozone pollution.

scholarly journals Using proxies to explore ensemble uncertainty in climate impact studies: the example of air pollution

2015 ◽  
Vol 15 (20) ◽  
pp. 28361-28393
Author(s):  
V. E. P. Lemaire ◽  
A. Colette ◽  
L. Menut
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Eastern Europe ◽  
Climate Model ◽  
Climate Impact ◽  
Northern Italy ◽  
Air Pollutant ◽  
Mitigation Measures ◽  
Training Dataset ◽  
The Impact

Abstract. Because of its sensitivity to unfavorable weather patterns, air pollution is sensitive to climate change so that, in the future, a climate penalty could jeopardize the expected efficiency of air pollution mitigation measures. A common method to assess the impact of climate on air quality consists in implementing chemistry-transport models forced by climate projection. However, the computing cost of such method requires optimizing ensemble exploration techniques. By using a training dataset of deterministic projection of climate and air quality over Europe, we identified the main meteorological drivers of air quality for 8 regions in Europe and developed simple statistical models that could be used to predict air pollutant concentrations. The evolution of the key climate variables driving either particulate or gaseous pollution allows concluding on the robustness of the climate impact on air quality. The climate benefit for PM2.5 was confirmed −0.96 (±0.18), −1.00 (±0.37), −1.16 ± (0.23) μg m−3, for resp. Eastern Europe, Mid Europe and Northern Italy and for the Eastern Europe, France, Iberian Peninsula, Mid Europe and Northern Italy regions a climate penalty on ozone was identified 10.11 (±3.22), 8.23 (±2.06), 9.23 (±1.13), 6.41 (±2.14), 7.43 (±2.02) μg m−3. This technique also allows selecting a subset of relevant regional climate model members that should be used in priority for future deterministic projections.

Sign in / Sign up

Export Citation Format

Share Document