scholarly journals Primary aerosol and secondary inorganic aerosol budget over the Mediterranean Basin during 2012 and 2013

2018 ◽  
Vol 18 (7) ◽  
pp. 4911-4934 ◽  
Author(s):  
Jonathan Guth ◽  
Virginie Marécal ◽  
Béatrice Josse ◽  
Joaquim Arteta ◽  
Paul Hamer
Keyword(s):  
Mediterranean Basin ◽  
Transport Model ◽  
Coastal Areas ◽  
Sea Salt ◽  
Anthropogenic Emissions ◽  
Carbonaceous Aerosols ◽  
Desert Dust ◽  
Inorganic Aerosols ◽  
The Mediterranean ◽  
The Mediterranean Basin

Abstract. In the frame of the Chemistry-Aerosol Mediterranean Experiment (ChArMEx), we analyse the budget of primary aerosols and secondary inorganic aerosols over the Mediterranean Basin during the years 2012 and 2013. To do this, we use two year-long numerical simulations with the chemistry-transport model MOCAGE validated against satellite- and ground-based measurements. The budget is presented on an annual and a monthly basis on a domain covering 29 to 47° N latitude and 10° W to 38° E longitude. The years 2012 and 2013 show similar seasonal variations. The desert dust is the main contributor to the annual aerosol burden in the Mediterranean region with a peak in spring, and sea salt being the second most important contributor. The secondary inorganic aerosols, taken as a whole, contribute a similar level to sea salt. The results show that all of the considered aerosol types, except for sea salt aerosols, experience net export out of our Mediterranean Basin model domain, and thus this area should be considered as a source region for aerosols globally. Our study showed that 11 % of the desert dust, 22.8 to 39.5 % of the carbonaceous aerosols, 35 % of the sulfate and 9 % of the ammonium emitted or produced into the study domain are exported. The main sources of variability for aerosols between 2012 and 2013 are weather-related variations, acting on emissions processes, and the episodic import of aerosols from North American fires. In order to assess the importance of the anthropogenic emissions of the marine and the coastal areas which are central for the economy of the Mediterranean Basin, we made a sensitivity test simulation. This simulation is similar to the reference simulation but with the removal of the international shipping emissions and the anthropogenic emissions over a 50 km wide band inland along the coast. We showed that around 30 % of the emissions of carbonaceous aerosols and 35 to 60 % of the exported carbonaceous aerosols originates from the marine and coastal areas. The formation of 23, 27 and 27 %, respectively of, ammonium, nitrate and sulfate aerosols is due to the emissions within the marine and coastal area.

scholarly journals Primary aerosols and secondary inorganic aerosols budget over the Mediterranean basin during 2012 and 2013

2017 ◽  
Author(s):  
Jonathan Guth ◽  
Virginie Marécal ◽  
Béatrice Josse ◽  
Joaquim Arteta
Keyword(s):  
Mediterranean Basin ◽  
Transport Model ◽  
Wide Band ◽  
Sea Salts ◽  
Monthly Basis ◽  
Desert Dust ◽  
Inorganic Aerosols ◽  
Sulphate Aerosols ◽  
The Mediterranean ◽  
The Mediterranean Basin

Abstract. In the frame of the Chemistry-Aerosol Mediterranean Experiment (ChArMEx), we analyse the budget of primary aerosols and secondary inorganic aerosols over the Mediterranean basin during the years 2012 and 2013. To do this, we use a two-years long numerical simulation with the Chemistry-Transport Model MOCAGE validated against satellite and ground based measurements. The budget is presented on an annual and a monthly basis on a domain covering 29° North to 47° North latitude and 10° West to 38° East longitude. The years 2012 and 2013 show similar seasonal variations. The desert dust is the main contributor to the annual burden in the Mediterranean region with a peak in spring. The secondary inorganic aerosols, taken as a whole, also contribute significantly as well as sea salts. Sulphate aerosols have a maximum in summer and sea salts in winter, while nitrate and ammonium aerosols do not exhibit large seasonal changes. The results show that all the considered types of aerosols, except for sea salt aerosols, have a net import/export term that is negative, meaning that aerosols emitted and chemically produced within the domain are transported out, with high values for some of them. For example, around 40 % of the emitted black carbon are exported. The main sources of changes between 2012 and 2013 are wind variations acting on the desert dust emissions and the import of aerosols from North American fires. In order to assess the importance of the emissions of the marine and the coastal areas, we made a sensitivity test simulation. This simulation is similar to the first one but with the removal of the anthropogenic emissions over the sea and over a 50 km wide band inland along the coast. It shows that about a third of the aerosols emitted and chemically produced and about a half of the exported part in the Mediterranean basin originate from the marine and coastal area, meaning that anthropogenic air pollution from primary aerosols and secondary inorganic aerosols in this region mainly comes from local emissions.

scholarly journals Impact of the Asian monsoon anticyclone on the variability of mid-to-upper tropospheric methane above the Mediterranean Basin

2014 ◽  
Vol 14 (20) ◽  
pp. 11427-11446 ◽  
Author(s):  
P. Ricaud ◽  
B. Sič ◽  
L. El Amraoui ◽  
J.-L. Attié ◽  
R. Zbinden ◽  
...  
Keyword(s):  
Mediterranean Basin ◽  
Near Infrared ◽  
Asian Monsoon ◽  
Climate Models ◽  
Transport Model ◽  
Lower Troposphere ◽  
Upper Troposphere ◽  
The Mediterranean ◽  
East West ◽  
The Mediterranean Basin

Abstract. The space and time variabilities of methane (CH4) total column and upper tropospheric mixing ratios are analysed above the Mediterranean Basin (MB) as part of the Chemical and Aerosol Mediterranean Experiment (ChArMEx) programme. Since the analysis of the mid-to-upper tropospheric CH4 distribution from spaceborne sensors and model outputs is challenging, we have adopted a climatological approach and have used a wide variety of data sets. We have combined spaceborne measurements from the Thermal And Near infrared Sensor for carbon Observations – Fourier Transform Spectrometer (TANSO-FTS) instrument on the Greenhouse gases Observing SATellite (GOSAT) satellite, the Atmospheric InfraRed Spectrometer (AIRS) on the AURA platform and the Infrared Atmospheric Sounder Interferometer (IASI) instrument aboard the MetOp-A platform with model results from the Chemical Transport Model (CTM) MOCAGE, and the Chemical Climate Models (CCMs) CNRM-AOCCM and LMDz-OR-INCA (according to different emission scenarios). In order to minimize systematic errors in the spaceborne measurements, we have only considered maritime pixels over the MB. The period of interest spans from 2008 to 2011 considering satellite and MOCAGE data and, regarding the CCMs, from 2001 to 2010. Although CH4 is a long-lived tracer with lifetime of ~12 years and is supposed to be well mixed in the troposphere, an east–west gradient in CH4 is observed and modelled in the mid-to-upper troposphere with a maximum in the Western MB in all seasons except in summer when CH4 accumulates above the Eastern MB. The peak-to-peak amplitude of the east–west seasonal variation in CH4 above the MB in the upper troposphere (300 hPa) is weak but almost twice as great in the satellite measurements (~25 ppbv) as in the model data (~15 ppbv). The maximum of CH4 in summer above the eastern MB can be explained by a series of dynamical processes only occurring in summer. The Asian monsoon traps and uplifts high amounts of CH4 to the upper troposphere where they build up. The Asian Monsoon Anticyclone redistributes these elevated CH4 amounts towards North Africa and the Middle East to finally reach and descend in the eastern MB. In the lower troposphere, the CH4 variability is mainly driven by the local sources of emission in the vicinity of the MB.

scholarly journals Characterization of PM<sub>10</sub> sources in the central Mediterranean

2015 ◽  
Vol 15 (14) ◽  
pp. 20013-20057
Author(s):  
G. Calzolai ◽  
S. Nava ◽  
F. Lucarelli ◽  
M. Chiari ◽  
M. Giannoni ◽  
...  
Keyword(s):  
Mediterranean Basin ◽  
Mineral Dust ◽  
Sea Salt ◽  
Biogenic Emissions ◽  
Ship Emissions ◽  
Central Mediterranean ◽  
Combustion Emissions ◽  
The Mediterranean ◽  
Pm10 Mass ◽  
The Mediterranean Basin

Abstract. The Mediterranean Basin atmosphere is influenced by both strong natural and anthropogenic aerosol emissions, and is also subject to important climatic forcings. Several programs have addressed the study of the Mediterranean basin; nevertheless important pieces of information are still missing. In this framework, PM10 samples were collected on a daily basis on the island of Lampedusa (35.5° N, 12.6° E, 45 m a.s.l.), which is far from continental pollution sources (the nearest coast, in Tunisia, is more than 100 km away). After mass gravimetric measurements, different portions of the samples were analyzed to determine the ionic content by Ion Chromatography (IC), the soluble metals by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES), and the total (soluble + insoluble) elemental composition by Particle Induced X-ray Emission (PIXE). Data from years 2007 and 2008 are used in this study. The Positive Matrix Factorization (PMF) model was applied to the 2 year long data set of PM10 mass concentration and chemical composition to assess the aerosol sources affecting the Central Mediterranean basin. Seven sources were resolved: sea-salt, mineral dust, biogenic emissions, primary particulate ship emissions, secondary sulphate, secondary nitrate, and combustion emissions. Source contributions to the total PM10 mass were estimated to be about 40 % for sea-salt, around 25 % for mineral dust, 10 % each for secondary nitrate and secondary sulphate, and 5 % each for primary particulate ship emissions, biogenic emissions, and combustion emissions. Large variations in absolute and relative contributions are found and appear to depend on the season and on transport episodes. In addition, the secondary sulphate due to ship emissions was estimated, and found to contribute by about one third to the total sulphate mass. Results for the sea-salt and mineral dust sources were compared with estimates of the same contributions obtained from independent approaches, leading to an estimate of the water content bound to the sea salt in the marine source.

scholarly journals Characterization of PM<sub>10</sub> sources in the central Mediterranean

2015 ◽  
Vol 15 (24) ◽  
pp. 13939-13955 ◽  
Author(s):  
G. Calzolai ◽  
S. Nava ◽  
F. Lucarelli ◽  
M. Chiari ◽  
M. Giannoni ◽  
...  
Keyword(s):  
Mediterranean Basin ◽  
Mineral Dust ◽  
Sea Salt ◽  
Biogenic Emissions ◽  
Ship Emissions ◽  
Central Mediterranean ◽  
Combustion Emissions ◽  
The Mediterranean ◽  
Pm10 Mass ◽  
The Mediterranean Basin

Abstract. The Mediterranean Basin atmosphere is influenced by both strong natural and anthropogenic aerosol emissions and is also subject to important climatic forcings. Several programs have addressed the study of the Mediterranean basin; nevertheless important pieces of information are still missing. In this framework, PM10 samples were collected on a daily basis on the island of Lampedusa (35.5° N, 12.6° E; 45 m a.s.l.), which is far from continental pollution sources (the nearest coast, in Tunisia, is more than 100 km away). After mass gravimetric measurements, different portions of the samples were analyzed to determine the ionic content by ion chromatography (IC), the soluble metals by inductively coupled plasma atomic emission spectrometry (ICP-AES), and the total (soluble + insoluble) elemental composition by particle-induced x-ray emission (PIXE). Data from 2007 and 2008 are used in this study. The Positive Matrix Factorization (PMF) model was applied to the 2-year long data set of PM10 mass concentration and chemical composition to assess the aerosol sources affecting the central Mediterranean basin. Seven sources were resolved: sea salt, mineral dust, biogenic emissions, primary particulate ship emissions, secondary sulfate, secondary nitrate, and combustion emissions. Source contributions to the total PM10 mass were estimated to be about 40 % for sea salt, around 25 % for mineral dust, 10 % each for secondary nitrate and secondary sulfate, and 5 % each for primary particulate ship emissions, biogenic emissions, and combustion emissions. Large variations in absolute and relative contributions are found and appear to depend on the season and on transport episodes. In addition, the secondary sulfate due to ship emissions was estimated and found to contribute by about one-third to the total sulfate mass. Results for the sea-salt and mineral dust sources were compared with estimates of the same contributions obtained from independent approaches, leading to an estimate of the water content bound to the sea salt in the marine source.

scholarly journals Variability of tropospheric methane above the Mediterranean Basin inferred from satellite and model data

2014 ◽  
Vol 14 (7) ◽  
pp. 9975-10024
Author(s):  
P. Ricaud ◽  
B. Sič ◽  
L. El Amraoui ◽  
J.-L. Attié ◽  
P. Huszar ◽  
...  
Keyword(s):  
Middle East ◽  
Atlantic Ocean ◽  
Mediterranean Basin ◽  
Near Infrared ◽  
Asian Monsoon ◽  
Transport Model ◽  
Emission Scenarios ◽  
The West ◽  
The Mediterranean ◽  
The Mediterranean Basin

Abstract. The space and time variabilities of methane (CH4) total column and upper tropospheric mixing ratios are analyzed above the Mediterranean Basin (MB) as part of the Chemical and Aerosol Mediterranean Experiment (ChArMEx) programme. Spaceborne measurements from the Thermal And Near infrared Sensor for carbon Observations-Fourier Transform Spectrometer (TANSO-FTS) instrument on the Greenhouse gases Observing SATellite (GOSAT) satellite, the Atmospheric InfraRed Spectrometer (AIRS) on the AURA platform and the Infrared Atmospheric Sounder Interferometer (IASI) instrument aboard the MetOp-A platform are used in conjunction with model results from the Chemical Transport Model (CTM) MOCAGE, and the Chemical Climate Models (CCMs) CNRM-AOCCM and LMDz-OR-INCA (according to different emission scenarios). In order to minimize systematic errors in the spaceborne measurements, we have only considered maritime pixels over the MB. The period under interest spans from 2008 to 2011 considering satellite and MOCAGE data and, regarding the CCMs, from 2001 to 2010. An East-West gradient in CH4 is observed and modelled whatever the season considered. In winter, air masses mainly originating from Atlantic Ocean and Europe tend to favour an elevated amount of mid-to-upper tropospheric CH4 in the West vs. the East of the MB, with a general upward transport above the MB. In summer, the meteorological state of the MB is changed, favouring air from Northern Africa and Middle East together with Atlantic Ocean and Europe, with a general downward motion above the MB. The Asian Monsoon traps and uplifts high amounts of CH4 that are transported towards North Africa and Middle East by the Asian Monsoon Anticyclone to finally reach and descent in the East of the MB. Consequently, the mid-to-upper tropospheric CH4 is much greater in the East than in the West of the MB. The seasonal variation of the difference in CH4 between the East and the West MB does show a maximum in summer for pressures from 500 to 100 hPa considering both spaceborne measurements and model results whatever the emission scenarios used. From this study, we can conclude that CH4 in the mid-to-upper troposphere over the MB is mainly affected by long-range transport, particularly intense in summer from Asia. In the low-to-mid troposphere, the local sources of emission in the vicinity of the MB mainly affect the CH4 variability.

scholarly journals Intercontinental transport of biomass burning pollutants over the Mediterranean Basin during the summer 2014 ChArMEx-GLAM airborne campaign

2018 ◽  
Vol 18 (9) ◽  
pp. 6887-6906 ◽  
Author(s):  
Vanessa Brocchi ◽  
Gisèle Krysztofiak ◽  
Valéry Catoire ◽  
Jonathan Guth ◽  
Virginie Marécal ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Mediterranean Basin ◽  
Transport Model ◽  
Particle Dispersion ◽  
Transport Processes ◽  
Atmospheric Composition ◽  
Air Mass ◽  
Air Masses ◽  
The Mediterranean ◽  
The Mediterranean Basin

Abstract. The Gradient in Longitude of Atmospheric constituents above the Mediterranean basin (GLAM) campaign was set up in August 2014, as part of the Chemistry and Aerosol Mediterranean Experiment (ChArMEx) project. This campaign aimed to study the chemical variability of gaseous pollutants and aerosols in the troposphere along a west–east transect above the Mediterranean Basin (MB). In the present work, we focus on two biomass burning events detected at 5.4 and 9.7 km altitude above sea level (a.s.l.) over Sardinia (from 39∘12′ N–9∘15′ E to 35∘35′ N–12∘35′ E and at 39∘30′ N–8∘25′ E, respectively). Concentration variations in trace gas carbon monoxide (CO), ozone (O3) and aerosols were measured thanks to the standard instruments on board the Falcon 20 aircraft operated by the Service des Avions Français Instrumentés pour la Recherche en Environnement (SAFIRE) and the Spectromètre InfraRouge In situ Toute Altitude (SPIRIT) developed by LPC2E. Twenty-day backward trajectories with Lagrangian particle dispersion model FLEXPART (FLEXible PARTicle) help to understand the transport processes and the origin of the emissions that contributed to this pollution detected above Sardinia. Biomass burning emissions came (i) on 10 August from the North American continent with air masses transported during 5 days before arriving over the MB, and (ii) on 6 August from Siberia, with air masses travelling during 12 days and enriched in fire emission products above Canada 5 days before arriving over the MB. In combination with the Global Fire Assimilation System (GFAS) inventory and the Moderate Resolution Imaging Spectroradiometer (MODIS) satellite fire locations, FLEXPART reproduces well the contribution of those fires to CO and aerosols enhancements under adjustments of the injection height to 10 km in both cases and application of an amplification factor of 2 on CO GFAS emissions for the 10 August event. The chemistry transport model (CTM) MOCAGE is used as a complementary tool for the case of 6 August to confirm the origin of the emissions by tracing the CO global atmospheric composition reaching the MB. For this event, both models agree on the origin of air masses with CO concentrations simulated with MOCAGE lower than the observed ones, likely caused by the coarse model horizontal resolution that yields the dilution of the emissions and diffusion during transport. In combination with wind fields, the analysis of the transport of the air mass documented on 6 August suggests the subsidence of CO pollution from Siberia towards North America and then a transport to the MB via fast jet winds located at around 5.5 km in altitude. Finally, using the ratio ΔO3 ∕ ΔCO, the plume age can be estimated and the production of O3 during the transport of the air mass is studied using the MOCAGE model.

scholarly journals Intercontinental transport of biomass burning pollutants over the Mediterranean Basin during the summer 2014 ChArMEx-GLAM airborne campaign

2017 ◽  
Author(s):  
Vanessa Brocchi ◽  
Gisèle Krysztofiak ◽  
Valéry Catoire ◽  
Jonathan Guth ◽  
Virginie Marécal ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Mediterranean Basin ◽  
Transport Model ◽  
Dispersion Model ◽  
Particle Dispersion ◽  
Transport Processes ◽  
Atmospheric Composition ◽  
Air Masses ◽  
The Mediterranean ◽  
The Mediterranean Basin

Abstract. The Gradient in Longitude of Atmospheric constituents above the Mediterranean basin (GLAM) campaign was set up in August 2014, as part of the Chemistry-Aerosol Mediterranean Experiment (ChArMEx) project. This campaign aimed at studying the chemical variability of gaseous pollutants and aerosols in the troposphere along a West-East transect above the Mediterranean Basin (MB). In the present work, we focus on two biomass burning events detected at 5.4 and 9.7 km altitude above sea level (asl) above Sardinia (from 39°12 N–9°15 E to 35°35 N–12°35 E and at 39°30 N–8°25 E, respectively). Concentration variations in trace gas carbon monoxide (CO) and aerosols were measured thanks to the standard instruments on-board the Falcon-20 aircraft operated by the Service des Avions Français Instrumentés pour la Recherche en Environnement (SAFIRE) and the Spectromètre InfraRouge In situ Toute Altitude (SPIRIT) developed by LPC2E. 20-day backward trajectories with Lagrangian particle dispersion model FLEXPART (FLEXible PARTicle) help understanding the transport processes and the origin of the emissions that contributed to these pollutions detected above Sardinia. Biomass burning emissions came (i) on 10 August from the Northern American continent with air masses transported during 5 days before arriving over the MB, and (ii) on 6 August from Siberia with air masses travelling during 12 days and enriched in fire emission products above Canada 5 days before arriving over the MB. In combination with the Global Fire Assimilation System (GFAS) inventory and the Moderate Resolution Imaging Spectroradiometer (MODIS) satellite fire locations, FLEXPART reproduces well the contribution of those fires to CO and aerosols enhancements under adjustments of the injection height to 10 km in both cases, and application of an amplification factor of 2.5 on CO GFAS emissions for the 10 August event. The chemistry transport model (CTM) MOCAGE is used as a complementary tool for the case of 6 August to confirm the origin of the emissions by tracing the CO global atmospheric composition reaching the MB. For this event, both models agree on the origin of air masses with CO concentrations simulated with MOCAGE lower than the observed ones, likely caused by the coarse model horizontal resolution that yields the dilution of the emissions and diffusion during transport. In combination with wind fields, the analysis of the transport of the air mass documented on 6 August suggests the subsidence of CO pollution from Siberia towards North America and then a transport to the MB via fast jet winds located at around 5.5 km in altitude.

scholarly journals Comparison of two different sea-salt aerosol schemes as implemented in air quality models applied to the Mediterranean Basin

2010 ◽  
Vol 10 (12) ◽  
pp. 30999-31038
Author(s):  
P. Jimenez-Guerrero ◽  
O. Jorba ◽  
M. T. Pay ◽  
J. P. Montavez ◽  
S. Jerez ◽  
...  
Keyword(s):  
Dry Deposition ◽  
Wet Deposition ◽  
Mediterranean Basin ◽  
Surface Wind ◽  
Mediterranean Area ◽  
Sea Salt ◽  
Target Area ◽  
Transport Models ◽  
The Mediterranean ◽  
The Mediterranean Basin

Abstract. A number of attempts have been made to incorporate sea-salt aerosols (SSA) source functions in chemistry transport models with varying results according to the complexity of the scheme considered. This contribution compares the inclusion of two different SSA algorithms in two chemistry transport models: CMAQ and CHIMERE. The main goal is to examine the differences in average SSA mass and composition and to study the seasonality of the prediction of SSA when applied to the Mediterranean area with high resolution in a reference year. Dry and wet deposition schemes are also analyzed to better understand the differences observed between both models in the target area. The applied emission algorithm in CHIMERE uses a semi-empirical formulation which obtains the surface emission rate of SSA as a function of the surface wind speed cubed and particle size. The emission parameterization included within CMAQ is somehow more sophisticated, since fluxes of SSA are corrected with relative humidity. In order to evaluate their strengths and weaknesses, the participating algorithms as implemented in the chemistry transport models were evaluated against AOD measurements from Aeronet and available surface measurements in Southern Europe and the Mediterranean area, showing biases around −0.003 and −1.2 μg m−3, respectively. The results indicate that both models represent accurately the patterns and dynamics of SSA and its non-uniform behavior in the Mediterranean basin, showing a strong seasonality. The levels of SSA vary strongly across the Western and the Eastern Mediterranean, reproducing CHIMERE higher annual levels in the Aegean Sea (12 μg m−3) and CMAQ in the Gulf of Lion (9 μg m−3). The large difference found for the ratio PM2.5/total SSA in CMAQ and CHIMERE is also investigated. The dry and wet removal rates are very similar for both models despite the different schemes implemented. Dry deposition essentially follows the surface drag stress patterns, meanwhile wet deposition is more scattered over the continent. CMAQ tends to provide larger amounts of SSA dry deposition over the Northern Mediterranean (0.7–1.0 g m−2 yr−1), meanwhile the Southeastern Mediterranean accounts for the maximum annual dry deposition in the CHIMERE model (0.9–1.5 g m−2 yr−1). The wet deposition is dominated by the accumulation mode and is strongly correlated to the precipitation patterns, showing CMAQ a higher wet deposition/total deposition ratio over coastal mountain chains. The results of both models constitute a step towards increasing the understanding of the SSA dynamics in a complex area as the Mediterranean.

scholarly journals Source contributions to 2012 summertime aerosols in the Euro-Mediterranean region

2015 ◽  
Vol 15 (6) ◽  
pp. 8191-8242 ◽  
Author(s):  
G. Rea ◽  
S. Turquety ◽  
L. Menut ◽  
R. Briant ◽  
S. Mailler ◽  
...  
Keyword(s):  
Mediterranean Basin ◽  
Mineral Dust ◽  
Mediterranean Area ◽  
Sea Salt ◽  
Anthropogenic Emissions ◽  
The European Union ◽  
Natural Sources ◽  
Fire Emissions ◽  
The Mediterranean ◽  
The Impact

Abstract. In the Mediterranean area, aerosols may originate from anthropogenic or natural emissions (biogenic, mineral dust, fire and sea salt) before undergoing complex chemistry. In case of a huge pollution event, it is important to know if european pollution limits are exceeded and, if yes, if the pollution is due to anthropogenic or natural sources. In this study, the relative contribution of emissions to surface PM10, surface PM2.5 and total aerosol optical depth (AOD) is quantified. For Europe and the Mediterranean regions and during the summer of 2012, the WRF and CHIMERE models are used to perform a sensitivity analysis: one simulation with all sources (reference) and all others with one source removed. The reference simulation is compared to data from the AirBase and AERONET networks and the MODIS satellite instrument to quantify the ability of the model to reproduce the observations. It is shown that the correlation ranges from 0.38 to 0.49 for surface particulate matter and from 0.35 to 0.75 for AOD. The sensitivity simulations are analysed to quantify the impact of each source. For the summer of 2012, the model shows that the region (from −10° W to 40° E and from 30 to 55° N) is mainly influenced by aerosols due to mineral dust and anthropogenic emissions (62 and 19% respectively of total surface PM10 and 17 and 52% of total surface PM2.5). The western part of the Mediterranean is strongly influenced by mineral dust emissions (86% for surface PM10 and 44% for PM2.5), while anthropogenic emissions dominate in the northern Mediterranean basin (up to 75% for PM2.5). Fire emissions are more sporadic but may represent 20% of surface PM2.5 near local sources. Sea salt mainly contribute for coastal sites (up to 29%) and biogenic emissions mainly in Central Europe (up to 20%). The same analysis was undertaken for the number of stations in daily exceedances of the European Union limit of 50 μg m−3 for PM10 (over the AirBase stations). This number is generally overestimated by the model, particularly in the northern part of the domain, but exceedances are captured at the right time. The discrepancies are most probably due to an overestimation of dust at the surface, and particularly when diverse sources are mixed. If natural sources as mineral dust events are particularly difficult to estimate, their contribution to the exceedances of the limitation is preponderant during the summer of 2012 (from 35% in the northern part of the Mediterranean basin to 92.5% in the western part).

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