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Qi Zhang - One of the best experts on this subject based on the ideXlab platform.
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regional influence of wildfires on Aerosol Chemistry in the western us and insights into atmospheric aging of biomass burning organic Aerosol
Atmospheric Chemistry and Physics, 2016Co-Authors: Shan Zhou, Sonya Collier, Arthur J Sedlacek, Daniel A Jaffe, Nicole L Briggs, Lawrence I Kleinman, Timothy B Onasch, Qi ZhangAbstract:Abstract. Biomass burning (BB) is one of the most important contributors to atmospheric Aerosols on a global scale, and wildfires are a large source of emissions that impact regional air quality and global climate. As part of the Biomass Burning Observation Project (BBOP) field campaign in summer 2013, we deployed a high-resolution time-of-flight Aerosol mass spectrometer (HR-AMS) coupled with a thermodenuder at the Mt. Bachelor Observatory (MBO, ∼ 2.8 km above sea level) to characterize the impact of wildfire emissions on Aerosol loading and properties in the Pacific Northwest region of the United States. MBO represents a remote background site in the western US, and it is frequently influenced by transported wildfire plumes during summer. Very clean conditions were observed at this site during periods without BB influence where the 5 min average (±1σ) concentration of non-refractory submicron Aerosols (NR-PM1) was 3.7 ± 4.2 µg m−3. Aerosol concentration increased substantially (reaching up to 210 µg m−3 of NR-PM1) for periods impacted by transported BB plumes, and Aerosol composition was overwhelmingly organic. Based on positive matrix factorization (PMF) of the HR-AMS data, three types of BB organic Aerosol (BBOA) were identified, including a fresh, semivolatile BBOA-1 (O ∕ C = 0.35; 20 % of OA mass) that correlated well with ammonium nitrate; an intermediately oxidized BBOA-2 (O ∕ C = 0.60; 17 % of OA mass); and a highly oxidized BBOA-3 (O ∕ C = 1.06; 31 % of OA mass) that showed very low volatility with only ∼ 40 % mass loss at 200 °C. The remaining 32 % of the OA mass was attributed to a boundary layer (BL) oxygenated OA (BL-OOA; O ∕ C = 0.69) representing OA influenced by BL dynamics and a low-volatility oxygenated OA (LV-OOA; O ∕ C = 1.09) representing regional Aerosols in the free troposphere. The mass spectrum of BBOA-3 resembled that of LV-OOA and had negligible contributions from the HR-AMS BB tracer ions – C2H4O2+ (m∕z = 60.021) and C3H5O2+ (m∕z = 73.029); nevertheless, it was unambiguously related to wildfire emissions. This finding highlights the possibility that the influence of BB emission could be underestimated in regional air masses where highly oxidized BBOA (e.g., BBOA-3) might be a significant Aerosol component but where primary BBOA tracers, such as levoglucosan, are depleted. We also examined OA chemical evolution for persistent BB plume events originating from a single fire source and found that longer solar radiation led to higher mass fraction of the chemically aged BBOA-2 and BBOA-3 and more oxidized Aerosol. However, an analysis of the enhancement ratios of OA relative to CO (ΔOA ∕ΔCO) showed little difference between BB plumes transported primarily at night versus during the day, despite evidence of substantial chemical transformation in OA induced by photooxidation. These results indicate negligible net OA production in photochemically aged wildfire plumes observed in this study, for which a possible reason is that SOA formation was almost entirely balanced by BBOA volatilization. Nevertheless, the formation and chemical transformation of BBOA during atmospheric transport can significantly influence downwind sites with important implications for health and climate.
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real time characterization of Aerosol particle composition above the urban canopy in beijing insights into the interactions between the atmospheric boundary layer and Aerosol Chemistry
Environmental Science & Technology, 2015Co-Authors: Wei Du, Qi Zhang, Qingqing Wang, Yong Chen, Zifa Wang, Chen Chen, Zhenyi Chen, Pingqing Fu, Douglas R WorsnopAbstract:Despite extensive efforts into the characterization of air pollution during the past decade, real-time characterization of Aerosol particle composition above the urban canopy in the megacity Beijing has never been performed to date. Here we conducted the first simultaneous real-time measurements of Aerosol composition at two different heights at the same location in urban Beijing from December 19, 2013 to January 2, 2014. The nonrefractory submicron Aerosol (NR-PM1) species were measured in situ by a high-resolution Aerosol mass spectrometer at near-ground level and an Aerosol chemical speciation monitor at 260 m on a 325 m meteorological tower in Beijing. Secondary Aerosol showed similar temporal variations between ground level and 260 m, whereas much weaker correlations were found for the primary Aerosol. The diurnal evolution of the ratios and correlations of Aerosol species between 260 m and the ground level further illustrated a complex interaction between vertical mixing processes and local source e...
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real time characterization of Aerosol particle composition above the urban canopy in beijing insights into the interactions between the atmospheric boundary layer and Aerosol Chemistry
Environmental Science & Technology, 2015Co-Authors: Yele Sun, Qi Zhang, Qingqing Wang, Yong Chen, Zifa Wang, Zhiqiu Gao, Chen Chen, Zhenyi Chen, Douglas R WorsnopAbstract:Despite extensive efforts into the characterization of air pollution during the past decade, real-time characterization of Aerosol particle composition above the urban canopy in the megacity Beijing has never been performed to date. Here we conducted the first simultaneous real-time measurements of Aerosol composition at two different heights at the same location in urban Beijing from December 19, 2013 to January 2, 2014. The nonrefractory submicron Aerosol (NR-PM1) species were measured in situ by a high-resolution Aerosol mass spectrometer at near-ground level and an Aerosol chemical speciation monitor at 260 m on a 325 m meteorological tower in Beijing. Secondary Aerosol showed similar temporal variations between ground level and 260 m, whereas much weaker correlations were found for the primary Aerosol. The diurnal evolution of the ratios and correlations of Aerosol species between 260 m and the ground level further illustrated a complex interaction between vertical mixing processes and local source emissions on Aerosol Chemistry in the atmospheric boundary layer. As a result, the Aerosol compositions at the two heights were substantially different. Organic Aerosol (OA), mainly composed of primary OA (62%), at the ground level showed a higher contribution to NR-PM1 (65%) than at 260 m (54%), whereas a higher concentration and contribution (15%) of nitrate was observed at 260 m, probably due to the favorable gas-particle partitioning under lower temperature conditions. In addition, two different boundary layer structures were observed, each interacting differently with the evolution processes of Aerosol Chemistry.
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long term measurements of submicrometer Aerosol Chemistry at the southern great plains sgp using an Aerosol chemical speciation monitor acsm
Atmospheric Environment, 2015Co-Authors: Caroline L Parworth, Fan Mei, Jerome D Fast, Tim Shippert, Chitra Sivaraman, Alison Tilp, Thomas Watson, Qi ZhangAbstract:Abstract In this study the long-term trends of non-refractory submicrometer Aerosol (NR-PM1) composition and mass concentration measured by an Aerosol Chemical Speciation Monitor (ACSM) at the Atmospheric Radiation Measurement (ARM) program's Southern Great Plains (SGP) site are discussed. NR-PM1 data was recorded at ∼30 min intervals over a period of 19 months between November 2010 and June 2012. Positive Matrix Factorization (PMF) was performed on the measured organic mass spectral matrix using a rolling window technique to derive factors associated with distinct sources, evolution processes, and physiochemical properties. The rolling window approach also allows us to capture the dynamic variations of the chemical properties in the organic Aerosol (OA) factors over time. Three OA factors were obtained including two oxygenated OA (OOA) factors, differing in degrees of oxidation, and a biomass burning OA (BBOA) factor. Back trajectory analyses were performed to investigate possible sources of major NR-PM1 species at the SGP site. Organics dominated NR-PM1 mass concentration for the majority of the study with the exception of winter, when ammonium nitrate increases due to transport of precursor species from surrounding urban and agricultural areas and also due to cooler temperatures. Sulfate mass concentrations have little seasonal variation with mixed regional and local sources. In the spring BBOA emissions increase and are mainly associated with local fires. Isoprene and carbon monoxide emission rates were obtained by the Model of Emissions of Gases and Aerosols from Nature (MEGAN) and the 2011 U.S. National Emissions Inventory to represent the spatial distribution of biogenic and anthropogenic sources, respectively. The combined spatial distribution of isoprene emissions and air mass trajectories suggest that biogenic emissions from the southeast contribute to SOA formation at the SGP site during the summer.
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measurement of atmospheric amines and ammonia using the high resolution time of flight chemical ionization mass spectrometry
Atmospheric Environment, 2015Co-Authors: Jun Zheng, Qi Zhang, Mindong Chen, Lin Wang, Alexei F Khalizov, Lei Yao, Zhen Wang, Xing Wang, Linxi ChenAbstract:Ammonia (NH3) and amines play important roles in the nucleation and growth of atmospheric Aerosols. To identify the sources of these chemicals in the densely populated and industrialized Yangtze River Delta region of China, we conducted measurements of NH3 and several amines, including methylamine (CH3NH2), C2-amines (C2H7N), and C3-amines (C3H9N) at a suburban site of Nanjing, China, during summer 2012. Using a high-resolution time-of-flight chemical ionization mass spectrometer (HRToF-CIMS, Aerodyne), 1-min-averaged concentrations of NH3 and amines ranged from a few parts per trillions by volume (pptv) to dozens of parts per billion by volume (ppbv). The average ± 1σ concentrations of NH3 and total amines during the measurement period were 1.7 ± 2.3 ppbv and 7.2 ± 7.4 pptv, respectively. Among the amines, C2-amines were the most abundant, accounting for 54% of the total amine loading. Significant correlations between NH3 and all three types of amines (0.65 < r2 < 0.80) indicate similar emission sources. Analysis of meteorological conditions indicated that these NH3 and amine laden air masses mainly originated from nearby industrial areas where NH3 was used for selective catalytic reduction of nitrogen oxides (NOx). The results of this work indicate that industrial emissions in Nanjing, China may have a significant impact on local and regional Aerosol Chemistry by supplying considerable amount of amines.
Yele Sun - One of the best experts on this subject based on the ideXlab platform.
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influences of upwind emission sources and atmospheric processing on Aerosol Chemistry and properties at a rural location in the northeastern u s
Journal of Geophysical Research, 2016Co-Authors: Shan Zhou, Yele Sun, Sonya Collier, Fan Mei, Jian Wang, Yin Nan Lee, Arthur J Sedlacek, Stephen R SpringstonAbstract:Continuous real-time measurements of atmospheric Aerosol with an Aerodyne high-resolution time-of-flight Aerosol mass spectrometer coupled with a fast temperature-stepping thermodenuder were carried out in summer 2011 at Brookhaven National Laboratory (BNL, 40.871°N, 72.89°W) during the Department of Energy Aerosol Life Cycle Intensive Operational Period campaign. BNL was frequently downwind of emissions from the New York metropolitan area and was exposed to various combinations of anthropogenic, biogenic, and marine emissions based on air mass history. The average concentration of submicrometer Aerosol (PM1) during this study was 12.6 µg m−3 with 64% of the mass being organic. Organic Aerosol (OA) at BNL was found to be overwhelmingly secondary, consisting of (1) a fresher, semivolatile oxygenated organic Aerosol (SV-OOA; oxygen-to-carbon ratio (O/C) = 0.54; 63% of OA mass) that was strongly influenced by transported urban plumes; (2) a regional, more aged, low-volatility OOA (LV-OOA; O/C = 0.97; 29% of OA mass) influenced by aqueous-phase processing; and (3) a nitrogen-enriched OA (NOA; nitrogen-to-carbon ratio (N/C) = 0.185; 8% of OA mass) likely composed of amine salts formed from acid-base reactions in industrial emissions. Urban emissions from the New York metropolitan areas to the W and SW in particular led to elevated PM1 mass concentration and altered Aerosol composition at BNL. Transported urban plumes and local biogenic emissions likely interacted to enhance secondary organic Aerosol production, primarily represented by SV-OOA. These results suggest an important role that urban anthropogenic emissions play in affecting ambient PM concentration, composition, and physical-chemical properties at rural areas in the Northeast U.S.
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real time characterization of Aerosol particle composition above the urban canopy in beijing insights into the interactions between the atmospheric boundary layer and Aerosol Chemistry
Environmental Science & Technology, 2015Co-Authors: Yele Sun, Qi Zhang, Qingqing Wang, Yong Chen, Zifa Wang, Zhiqiu Gao, Chen Chen, Zhenyi Chen, Douglas R WorsnopAbstract:Despite extensive efforts into the characterization of air pollution during the past decade, real-time characterization of Aerosol particle composition above the urban canopy in the megacity Beijing has never been performed to date. Here we conducted the first simultaneous real-time measurements of Aerosol composition at two different heights at the same location in urban Beijing from December 19, 2013 to January 2, 2014. The nonrefractory submicron Aerosol (NR-PM1) species were measured in situ by a high-resolution Aerosol mass spectrometer at near-ground level and an Aerosol chemical speciation monitor at 260 m on a 325 m meteorological tower in Beijing. Secondary Aerosol showed similar temporal variations between ground level and 260 m, whereas much weaker correlations were found for the primary Aerosol. The diurnal evolution of the ratios and correlations of Aerosol species between 260 m and the ground level further illustrated a complex interaction between vertical mixing processes and local source emissions on Aerosol Chemistry in the atmospheric boundary layer. As a result, the Aerosol compositions at the two heights were substantially different. Organic Aerosol (OA), mainly composed of primary OA (62%), at the ground level showed a higher contribution to NR-PM1 (65%) than at 260 m (54%), whereas a higher concentration and contribution (15%) of nitrate was observed at 260 m, probably due to the favorable gas-particle partitioning under lower temperature conditions. In addition, two different boundary layer structures were observed, each interacting differently with the evolution processes of Aerosol Chemistry.
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size resolved Aerosol Chemistry on whistler mountain canada with a high resolution Aerosol mass spectrometer during intex b
Atmospheric Chemistry and Physics, 2009Co-Authors: Yele Sun, Qi Zhang, A M Macdonald, Katherine Hayden, John Liggio, P S K Liu, K G Anlauf, W R Leaitch, Alexandra Steffen, M J CubisonAbstract:Abstract. An Aerodyne High Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) was deployed at the peak of Whistler Mountain (2182 m above sea level), British Columbia, from 19 April to 16 May 2006, as part of the Intercontinental Chemical Transport Experiment Phase B (INTEX-B) campaign. The mass concentrations and size distributions of non-refractory submicron particle (NR-PM1) species (i.e., sulfate, nitrate, ammonium, chloride, and organics) were measured in situ at 10-min time resolution. The HR-ToF-AMS results agreed well with collocated measurements. The average concentration of non-refractory submicron particulate matter (NR-PM1; 1.9 μg m−3) is similar to those observed at other remote, high elevation sites in North America. Episodes of enhanced Aerosol loadings were observed, due to influences of regional and trans-Pacific transport of air pollution. Organics and sulfate were the dominant species, on average accounting for 55% and 30%, respectively, of the NR-PM1 mass. The average size distributions of sulfate and ammonium both showed an accumulation mode peaking at ~500 nm in vacuum aerodynamic diameter (Dva) while those of organic Aerosol (OA) and nitrate peaked at ~300 nm. The size differences suggested that sulfate and OA were mostly present in external mixtures from different source origins. We also quantitatively determined the elemental composition of OA using the high resolution mass spectra. Overall, OA at Whistler Peak was highly oxygenated, with an average organic-mass-to-organic-carbon ratio (OM/OC) of 2.28±0.23 and an atomic ratio of oxygen-to-carbon (O/C) of 0.83±0.17. The nominal formula for OA was C1H1.66N0.03O0.83 for the entire study. Two significant trans-Pacific dust events originated from Asia were observed at Whistler Peak during this study. While both events were characterized with significant enhancements of coarse mode particles and mineral contents, the composition and characteristics of NR-PM1 were significantly different between them. One trans-Pacific event occurred on 15 May 2006, during which ammonium sulfate contributed >90% of the total NR-PM1 mass. This event was followed by a high OA episode likely associated with regional emissions. In total, three enhanced regional OA events, each of which lasted 2–3 days, were observed during this study. In contrast to the two dust events, the regional OA events were generally characterized with higher OA/sulfate ratio, less oxidized OA, and lower OM/OC ratio.
Pingqing Fu - One of the best experts on this subject based on the ideXlab platform.
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molecular markers of biomass burning fungal spores and biogenic soa in the taklimakan desert Aerosols
Atmospheric Environment, 2016Co-Authors: Zifa Wang, Pingqing Fu, Guoshun Zhuang, Qiongzhen Wang, Jing Chen, Fan Yang, Xiangdong Li, Kimitaka KawamuraAbstract:Abstract Biogenic primary organic Aerosols (POA) and secondary organic Aerosols (SOA) are important organic constituents of atmospheric particulate matter (PM). In order to better understand the atmospheric abundances, molecular compositions and sources of the desert Aerosols, biomass-burning tracers (e.g. levoglucosan), primary saccharides including fungal spore tracers, and SOA tracers from the oxidation of biogenic volatile organic compounds (e.g. isoprene, monoterpenes and sesquiterpene) have been studied in ambient Aerosols from the Taklimakan desert, using gas chromatography-mass spectrometry. Results showed that the total concentrations of biomass-burning tracers at Hetian (177–359 ng m −3 , mean 233 ng m −3 in PM 2.5 ) in the south rim of the desert were much higher than those at Tazhong (1.9–8.8 ng m −3 in PM 2.5 and 5.9–32 ng m −3 in TSP) in the central Taklimakan desert. Molecular markers of fungal spores were also detected in all the desert Aerosols, highlighting the importance of primary bioAerosols in the Asian dust particles. A specific pattern of the dominance of 2-methylglyceric acid over 2-methyltetrols and C 5 -alkene triols was found in the Taklimakan desert Aerosols, especially during the dust storm events, which is different from the 2-methyltetrols-dominated pattern in other ambient Aerosols. Our results provide direct evidence on the biogenic POA and SOA tracers in the Taklimakan desert region, which help to better understand their impact on the Aerosol Chemistry in the down-wind regions.
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real time characterization of Aerosol particle composition above the urban canopy in beijing insights into the interactions between the atmospheric boundary layer and Aerosol Chemistry
Environmental Science & Technology, 2015Co-Authors: Wei Du, Qi Zhang, Qingqing Wang, Yong Chen, Zifa Wang, Chen Chen, Zhenyi Chen, Pingqing Fu, Douglas R WorsnopAbstract:Despite extensive efforts into the characterization of air pollution during the past decade, real-time characterization of Aerosol particle composition above the urban canopy in the megacity Beijing has never been performed to date. Here we conducted the first simultaneous real-time measurements of Aerosol composition at two different heights at the same location in urban Beijing from December 19, 2013 to January 2, 2014. The nonrefractory submicron Aerosol (NR-PM1) species were measured in situ by a high-resolution Aerosol mass spectrometer at near-ground level and an Aerosol chemical speciation monitor at 260 m on a 325 m meteorological tower in Beijing. Secondary Aerosol showed similar temporal variations between ground level and 260 m, whereas much weaker correlations were found for the primary Aerosol. The diurnal evolution of the ratios and correlations of Aerosol species between 260 m and the ground level further illustrated a complex interaction between vertical mixing processes and local source e...
Adrien Deroubaix - One of the best experts on this subject based on the ideXlab platform.
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the role of Aerosol radiation cloud interactions in linking anthropogenic pollution over southern west africa and dust emission over the sahara
Atmospheric Chemistry and Physics, 2019Co-Authors: Laurent Menut, Cyrille Flamant, Adrien Deroubaix, Paolo Tuccella, Marco GaetaniAbstract:Abstract. The Aerosol direct and indirect effects are studied over west Africa in the summer of 2016 using the coupled WRF-CHIMERE regional model including Aerosol–cloud interaction parameterization. First, a reference simulation is performed and compared with observations acquired during the Dynamics-Aerosol-Chemistry-cloud interactions in West Africa (DACCIWA) field campaign which took place in June and July 2016. Sensitivity experiments are also designed to gain insights into the impact of the Aerosols dominating the atmospheric composition in southern west Africa (one simulation with halved anthropogenic emissions and one with halved mineral dust emissions). The most important effect of Aerosol–cloud interactions is found for the mineral dust scenario, and it is shown that halving the emissions of mineral dust decreases the 2 m temperature by 0.5 K and the boundary layer height by 25 m on a monthly average (July 2016) and over the Saharan region. The presence of dust Aerosols also increases (decreases) the shortwave (longwave) radiation at the surface by 25 W m −2 . It is also shown that the decrease of anthropogenic emissions along the coast has an impact on the mineral dust load over west Africa by increasing their emissions in the Saharan region. It is due to a mechanism where particulate matter concentrations are decreased along the coast, imposing a latitudinal shift of the monsoonal precipitation and, in turn, an increase of the surface wind speed over arid areas, inducing more mineral dust emissions.
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Local air pollution from oil rig emissions observed during the airborne DACCIWA campaign
Atmospheric Chemistry and Physics, 2019Co-Authors: Vanessa Brocchi, Gisele Krysztofiak, Adrien Deroubaix, Greta Stratmann, Daniel Sauer, Hans Schlager, Konrad Deetz, Guillaume Dayma, C Robert, Stéphane ChevrierAbstract:In the framework of the European DACCIWA (Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa) project, the airborne study APSOWA (Atmospheric Pollution from Shipping and Oil platforms of West Africa) was conducted in July 2016 to study oil rig emissions off the Gulf of Guinea. Two flights in the marine boundary layer were focused on the floating production storage and offload-ing (FPSO) vessel operating off the coast of Ghana. Those flights present simultaneous sudden increases in NO2 and Aerosol concentrations. Unlike what can be found in flaring emission inventories, no increase in SO2 was detected, and an increase in CO is observed only during one of the two flights. Using FLEXPART (FLEXible PARTicle dispersion model) simulations with a regional NO2 satellite flaring inventory in forward-trajectory mode, our study reproduces the timing of the aircraft NO2 enhancements. Several sensitivity tests on the flux and the injection height are also performed, leading to the conclusion that a lower NO2 flux helps in better reproducing the measurements and that the modification of the injection height does not impact the results of the simulations significantly.
Marco Gaetani - One of the best experts on this subject based on the ideXlab platform.
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the role of Aerosol radiation cloud interactions in linking anthropogenic pollution over southern west africa and dust emission over the sahara
Atmospheric Chemistry and Physics, 2019Co-Authors: Laurent Menut, Cyrille Flamant, Adrien Deroubaix, Paolo Tuccella, Marco GaetaniAbstract:Abstract. The Aerosol direct and indirect effects are studied over west Africa in the summer of 2016 using the coupled WRF-CHIMERE regional model including Aerosol–cloud interaction parameterization. First, a reference simulation is performed and compared with observations acquired during the Dynamics-Aerosol-Chemistry-cloud interactions in West Africa (DACCIWA) field campaign which took place in June and July 2016. Sensitivity experiments are also designed to gain insights into the impact of the Aerosols dominating the atmospheric composition in southern west Africa (one simulation with halved anthropogenic emissions and one with halved mineral dust emissions). The most important effect of Aerosol–cloud interactions is found for the mineral dust scenario, and it is shown that halving the emissions of mineral dust decreases the 2 m temperature by 0.5 K and the boundary layer height by 25 m on a monthly average (July 2016) and over the Saharan region. The presence of dust Aerosols also increases (decreases) the shortwave (longwave) radiation at the surface by 25 W m −2 . It is also shown that the decrease of anthropogenic emissions along the coast has an impact on the mineral dust load over west Africa by increasing their emissions in the Saharan region. It is due to a mechanism where particulate matter concentrations are decreased along the coast, imposing a latitudinal shift of the monsoonal precipitation and, in turn, an increase of the surface wind speed over arid areas, inducing more mineral dust emissions.