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

Pernigotti, Denise; Georgieva, Emilia; Thunis, Philippe; Bessagnet, Bertrand

doi:10.1016/j.atmosenv.2011.12.059

Cited by 48 publications

(23 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In order to perform a regionspecific data analysis, the model domain was divided into eight subregions, seven of which are similar or identical to the PRUDENCE (http://ensemblesrt3.dmi.dk/quicklook/ regions.html) climatic regions. The separation was also based on distinct local meteorological or chemical conditions such as in the Benelux area and the Po Valley in northern Italy (Colette et al, 2012;Pernigotti et al, 2012Pernigotti et al, , 2013. We used 14 sigma layers going up to 460 hPa with the first layer being approximately 20 m thick.…”

Section: Model Setupmentioning

confidence: 99%

“…The Benelux area is exposed to high NO x emissions from both land and shipping activities, leading to a more VOC-sensitive chemical regime for ozone production in this region (Beekmann and Vautard, 2010;Aksoyoglu et al, 2012). The geographical characteristics of the Po Valley in northern Italy led to a trap and accumulation of the pollutants in the area (de Meij et al, 2009a, b;Pernigotti et al, 2012Pernigotti et al, , 2013, which in return can also affect the nearby stations that are located in the MD region. For both the PV and BX regions, there is a consistent increase in modeled ozone mixing ratios for all bins, resulting in a decrease in the negative bias in higher bins and a slight increase in the positive bias in lower bins (Fig.…”

Section: Increased Voc Emissionsmentioning

confidence: 99%

See 1 more Smart Citation

Low modeled ozone production suggests underestimation of precursor emissions (especially NOx) in Europe

et al. 2018

View full text Add to dashboard Cite

Abstract. High surface ozone concentrations, which usually occur when photochemical ozone production takes place, pose a great risk to human health and vegetation. Air quality models are often used by policy makers as tools for the development of ozone mitigation strategies. However, the modeled ozone production is often not or not enough evaluated in many ozone modeling studies. The focus of this work is to evaluate the modeled ozone production in Europe indirectly, with the use of the ozone-temperature correlation for the summer of 2010 and to analyze its sensitivity to precursor emissions and meteorology by using the regional air quality model, the Comprehensive Air Quality Model with Extensions (CAMx). The results show that the model significantly underestimates the observed high afternoon surface ozone mixing ratios (≥ 60 ppb) by 10-20 ppb and overestimates the lower ones (< 40 ppb) by 5-15 ppb, resulting in a misleading good agreement with the observations for average ozone. The model also underestimates the ozone-temperature regression slope by about a factor of 2 for most of the measurement stations. To investigate the impact of emissions, four scenarios were tested: (i) increased volatile organic compound (VOC) emissions by a factor of 1.5 and 2 for the anthropogenic and biogenic VOC emissions, respectively, (ii) increased nitrogen oxide (NO x ) emissions by a factor of 2, (iii) a combination of the first two scenarios and (iv) increased trafficonly NO x emissions by a factor of 4. For southern, eastern, and central (except the Benelux area) Europe, doubling NO x emissions seems to be the most efficient scenario to reduce the underestimation of the observed high ozone mixing ratios without significant degradation of the model performance for the lower ozone mixing ratios. The model performance for ozone-temperature correlation is also better when NO x emissions are doubled. In the Benelux area, however, the third scenario (where both NO x and VOC emissions are increased) leads to a better model performance. Although increasing only the traffic NO x emissions by a factor of 4 gave very similar results to the doubling of all NO x emissions, the first scenario is more consistent with the uncertainties reported by other studies than the latter, suggesting that high uncertainties in NO x emissions might originate mainly from the road-transport sector rather than from other sectors. The impact of meteorology was examined with three sensitivity tests: (i) increased surface temperature by 4 • C, (ii) reduced wind speed by 50 % and (iii) doubled wind speed. The first two scenarios led to a consistent increase in all surface ozone mixing ratios, thus improving the model performance for the high ozone values but significantly degrading it for the low ozone values, while the third scenario had exactly the opposite effects. Overall, the modeled ozone is predicted to be more sensitive to its precursor emissions (especially traffic NO x ) and therefore their uncertainties, which seem to be responsible for the model un...

show abstract

Section: Model Setupmentioning

confidence: 99%

Section: Increased Voc Emissionsmentioning

confidence: 99%

Low modeled ozone production suggests underestimation of precursor emissions (especially NOx) in Europe

et al. 2018

View full text Add to dashboard Cite

show abstract

“…In this region, high levels of fine aerosol are mostly due to the conjunction of (i) high pollutant emissions related to industrial, transport, biomass burning and agricultural activities -the Po river basin hosting 37 % of the Italian industries, 55 % of the livestock and contributing 35 % of the Italian agricultural production (WMO et al, 2012) -and (ii) the specific geography and topography of this area -a flat basin surrounded by the Alps and Apennine Mountains dominated by weak winds that favour the accumulation of pollutants Kukkonen et al, 2005;Pernigotti et al, 2012). As a consequence, PM levels are high not only in urban areas but also at regional and rural background sites, which are key locations for investigating air pollution due to their distance from local sources and local phenomena.…”

Section: Introductionmentioning

confidence: 99%

Variations in the chemical composition of the submicron aerosol and in the sources of the organic fraction at a regional background site of the Po Valley (Italy)

et al. 2016

View full text Add to dashboard Cite

Abstract. Fine particulate matter (PM) levels and resulting impacts on human health are in the Po Valley (Italy) among the highest in Europe. To build effective PM abatement strategies, it is necessary to characterize fine PM chemical composition, sources and atmospheric processes on long timescales (> months), with short time resolution (< day), and with particular emphasis on the predominant organic fraction. Although previous studies have been conducted in this region, none of them addressed all these aspects together. For the first time in the Po Valley, we investigate the chemical composition of nonrefractory submicron PM (NR-PM1) with a time resolution of 30 min at the regional background site of Ispra during 1 full year, using the Aerodyne Aerosol Chemical Speciation Monitor (ACSM) under the most up-to-date and stringent quality assurance protocol. The identification of the main components of the organic fraction is made using the Multilinear-Engine 2 algorithm implemented within the latest version of the SoFi toolkit. In addition, with the aim of a potential implementation of ACSM measurements in European air quality networks as a replacement of traditional filter-based techniques, parallel multiple offline analyses were carried out to assess the performance of the ACSM in the determination of PM chemical species regulated by air quality directives. The annual NR-PM1 level monitored at the study site (14.2 µg m−3) is among the highest in Europe and is even comparable to levels reported in urban areas like New York City and Tokyo. On the annual basis, submicron particles are primarily composed of organic aerosol (OA, 58 % of NR-PM1). This fraction was apportioned into oxygenated OA (OOA, 66 %), hydrocarbon-like OA (HOA, 11 % of OA) and biomass burning OA (BBOA, 23 %). Among the primary sources of OA, biomass burning (23 %) is thus bigger than fossil fuel combustion (11 %). Significant contributions of aged secondary organic aerosol (OOA) are observed throughout the year. The unexpectedly high degree of oxygenation estimated during wintertime is probably due to the contribution of secondary BBOA and the enhancement of aqueous-phase production of OOA during cold months. BBOA and nitrate are the only components of which contributions increase with the NR-PM1 levels. Therefore, biomass burning and NOx emission reductions would be particularly efficient in limiting submicron aerosol pollution events. Abatement strategies conducted during cold seasons appear to be more efficient than annual-based policies. In a broader context, further studies using high-time-resolution analytical techniques on a long-term basis for the characterization of fine aerosol should help better shape our future air quality policies, which constantly need refinement.

show abstract

“…Following the most recent European studies, we investigate the impact of volatility distributions of organics emissions, S/IVOC emission parametrizations, SOA yields from gaseous precursors and different aging schemes, by implementing the latest experimental information available in the scientific literature. The study area is the Po Valley (Northern Italy) during wintertime (February-March 2013), which is a well-known hotspot where PM levels remain problematic despite the air quality remediation plans intended to get in compliance with current EU air quality standards, mainly because of adverse meteorological conditions (Caserini, et al, 2017;Perrino, et al, 2014;Pernigotti, et al, 2012;Ferrero, et al, 2011). We evaluate our model results against two OA-specific datasets, available for both an urban site (Bologna, February 2013) and a rural one (Ispra, March 2013).…”

Section: Introductionmentioning

confidence: 99%

Influence of semi- and intermediate-volatile organic compounds (S/IVOC) parameterizations, volatility distributions and aging schemes on organic aerosol modelling in winter conditions

Giani

Balzarini

Pirovano

et al. 2019

Atmospheric Environment

View full text Add to dashboard Cite

This study presents a high-resolution (5km) set of new simulations performed with CAMx v6.40 over the Po Valley area (Northern Italy), aimed to enhance organic aerosol (OA) levels prediction and to gain insight into the sensitivity of CAMx to different uncertain features of the input setup. In particular, we mainly investigated the role of (i) volatility distributions of organic emissions, (ii) parametrizations of semi-and intermediate-volatile compounds (S/IVOC) emissions and (iii) different aging schemes, by exploiting the latest experimental information available in the recent scientific literature. Model results were validated against two OA-specific datasets, available for both an urban site (Bologna, February 2013) and a rural one (Ispra, March 2013). We found out a remarkable performance enhancement of modelled OA levels when applying revisions in S/IVOC emission parametrizations together with the new volatility distributions, at both the validation sites. This performance enhancement is associated with a very significant improvement in secondary organic aerosol (SOA) prediction, mainly due to revised IVOC emissions. At Bologna urban site, mean fractional bias (MFB) of OA ranged from-80.1% in the worst run to-10.1% in the best one and index of agreement (IOA) from 0.52 to 0.75. Notable improvements but overall poorer metrics were found for Ispra site, where MFB ranges from-84.2% to-35% and IOA from 0.45 to 0.50. These findings indicate that organic matter in the semi-and intermediate-volatile range are most likely underestimated in official emission inventories for each main source category (i.e. biomass burning, diesel and gasoline vehicles exhaust). Finally, model results did not show a very pronounced sensitivity to aging processes, due to the low photochemical activity typically observed during winter-time. However, we give evidence that enabling aging processes for biomass burning related SOA, which is by default disabled in CAMx v6.40, can help in closing the gap between modelled and observed SOA concentrations. Highlights • Latest experimental studies about emissions of organic matter implemented in CAMx • Remarkable improvement on modelled organic aerosol levels • S/IVOC emission revisions appear to be the key factor for such improvement • Enabling aging processes for biomass burning SOA enhances the performance of the model • VBS provides a better reconstruction of POA and SOA relative contribution to the total Keywords.

show abstract

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

Cited by 48 publications

References 14 publications

Low modeled ozone production suggests underestimation of precursor emissions (especially NO<sub><i>x</i></sub>) in Europe

Low modeled ozone production suggests underestimation of precursor emissions (especially NO<sub><i>x</i></sub>) in Europe

Variations in the chemical composition of the submicron aerosol and in the sources of the organic fraction at a regional background site of the Po Valley (Italy)

Influence of semi- and intermediate-volatile organic compounds (S/IVOC) parameterizations, volatility distributions and aging schemes on organic aerosol modelling in winter conditions

Contact Info

Product

Resources

About

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

Cited by 48 publications

References 14 publications

Low modeled ozone production suggests underestimation of precursor emissions (especially NO&lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt;) in Europe

Low modeled ozone production suggests underestimation of precursor emissions (especially NO&lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt;) in Europe

Variations in the chemical composition of the submicron aerosol and in the sources of the organic fraction at a regional background site of the Po Valley (Italy)

Influence of semi- and intermediate-volatile organic compounds (S/IVOC) parameterizations, volatility distributions and aging schemes on organic aerosol modelling in winter conditions

Contact Info

Product

Resources

About

Low modeled ozone production suggests underestimation of precursor emissions (especially NO<sub><i>x</i></sub>) in Europe

Low modeled ozone production suggests underestimation of precursor emissions (especially NO<sub><i>x</i></sub>) in Europe