Top PDF Chemical composition and sources of coastal marine aerosol particles during the 2008 VOCALS-REx campaign

Chemical composition and sources of coastal marine aerosol particles during the 2008 VOCALS-REx campaign

Chemical composition and sources of coastal marine aerosol particles during the 2008 VOCALS-REx campaign

the coast when they were sampled. The particle size distri- butions from east to west on 28 October 2008 were highly uniform evidenced by a near constant droplet mode size at 0.18 µm and a progressively smaller Aitken mode size from ∼ 0.06 to ∼ 0.04 µm, reflecting emissions with similar char- acteristics that were more extensively processed and diluted going west along the ∼ 19 ◦ S parallel. The spectrum for the westernmost section, 77–77.3 ◦ W, showed some cloud con- tamination reflected in the increased small size particles from shattering, which however did not affect the mode sizes. In comparison, the data of 6 November 2008 showed still less processed emissions between 71 ◦ W and 72 ◦ W indicated by the much higher Aitken mode particle concentrations com- pared to that of the droplet mode with only a slight hint of the Hoppel minimum (Hoppel et al., 1986). The Aitken mode size decreased progressively from ∼ 0.07 µm to ∼ 0.04 µm from east to west similar to that observed on 28 October 2008. Regarding droplet mode particle size distributions, we note the concentrations decreased rapidly and steadily from east to west on 28 October 2008, but this decrease was much less pronounced on 6 November 2008 (Fig. 16). We surmise this rather steady droplet mode particle concentrations ob- served on 6 November 2008 across a wide longitude range was due to a more extensive cloud processing, growing more particles into the larger particle size range. The lower WS on 6 November 2008 compared to that of 28 October 2008 could allow a more extensive cloud processing because of an increased transport and reaction time. Finally, the droplet mode particle size is seen to decrease with distance from the coast on 6 November 2008, noting that while the left edges of the peaks were tightly clustered together, the right edges steadily retracted. In contrast, the droplet mode particle size observed on 28 October 2008 remained roughly constant as the number concentrations steadily decreased from east to west. We attribute this size shift observed on 6 November 2008 to the loss of larger sized particles to precipitation be- cause, all things equal, larger particles will be activated at lower supersaturations than smaller ones and lost through precipitation scavenging, which may also be consistent with a more extensive cloud processing.
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A statistical analysis of North East Atlantic (submicron) aerosol size distributions

A statistical analysis of North East Atlantic (submicron) aerosol size distributions

radiative effect). The shape of the aerosol size distribution is influenced by air mass origin which determines difference aerosol sources and evolution processes (Dall’Osto et al., 2010). Studies such as that of Dall’Osto et al. have focused on characterization via air mass origin over short periods of weeks to months rather than quantifying the frequency of oc- currence of each size distribution type over time scales of the order of a year (Charron et al., 2007; Costabile et al., 2009). Similarly, a number of studies have already focused on size distributions of particles detected at Mace Head, mainly focusing on marine aerosol constituents. Typical marine aerosol size distributions sampled at the coastal Mace Head research station showed low particle number concentrations with a sub-micron marine size distribution characterised by a bimodal shape, with an accumulation mode centred at 200 nm and an Aitken at 40 nm, indicative of a cloud-residual accumulation mode produced by the in-cloud growth of ac- tivated fine mode particles (Hoppel et al., 1994). A study on the seasonality of the clean marine particle size distributions was reported by Yoon et al. (2007), showing the aerosol size distribution modal diameters for different seasons: 31 nm in winter and 49 nm in summer for the Aitken mode and 103 nm in winter and 177 nm in summer for the accumulation mode, respectively. By contrast, air masses affected by anthro- pogenic pollution sampled at Mace Head during anticyclonic periods and conditions of continental outflow Aitken and ac- cumulation mode were enhanced by a factor of 5 compared to the marine sector (O’Dowd et al., 2001; Coe et al., 2006). As part of the EUCAARI (European Aerosol Cloud Cli- mate and Air Quality Interactions) Integrated Project, one of the major activities was to conduct and analyse size distribu- tion measurements at a range of European supersites (Kul- mala et al., 2009). The EUCAARI intensive measurement programme was throughout the full year of 2008. As one of the 12 atmospheric supersites EUCAARI supersites, Mace Head (Ireland) is uniquely located on the interface between the NE Atlantic and Europe, thus enabling sampling of both the cleanest air entering into Europe along with some of the most polluted air being exported out of Europe into the N. Atlantic (Jennings et al., 2003; O’Connor et al., 2008). Asmi et al. (2011) presented a combined statistical analysis of 22 stations (including all the 12 EUCAARI supersites) for the year 2008–2009 in terms of means and extremes of the num- ber concentration size distributions encountered.
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Chemical composition, microstructure, and hygroscopic properties of aerosol particles at the Zotino Tall Tower Observatory (ZOTTO), Siberia, during a summer campaign

Chemical composition, microstructure, and hygroscopic properties of aerosol particles at the Zotino Tall Tower Observatory (ZOTTO), Siberia, during a summer campaign

Carbon monoxide (CO) is used as a transport tracer for pollutant plumes. CO mixing ratios in air sampled from 300 m were measured by UV resonance fluorescence, using a Fast-CO-Monitor (model AL 5002, Aerolaser GmbH, Ger- many). Details of the experimental setup and calibration are described elsewhere (Chi et al., 2013). The CO mixing ra- tios observed during the sampling campaign are shown in Table 1. The daily average CO values correlate well with the backward trajectories and MODIS AOD product. Thus the elevated CO observed from 19 to 20 June can be attributed to air masses that passed over wildfires located to the east of the site (Fig. 1). Overall, during the sampling campaign the av- erage CO mixing ratio was ∼ 113 ppb, which corresponds to “background” conditions in June at the ZOTTO site (Chi et al., 2013). Using the definition of Andreae (2007) and Chi et al. (2013), we refer to “background” conditions as an atmo- spheric state without the detectable influence of local or re- gional pollution sources but affected by emissions from nat- ural origin as well as pollution transported from very distant sources.
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Seasonal variations in aerosol particle composition at the puy-de-Dôme research station in France

Seasonal variations in aerosol particle composition at the puy-de-Dôme research station in France

Abstract. Detailed investigations of the chemical and microphysical properties of atmospheric aerosol particles were performed at the puy-de-Dˆome (pdD) research station (1465 m) in autumn (September and October 2008), winter (February and March 2009), and summer (June 2010) using a compact Time-of-Flight Aerosol Mass Spectrometer (cToF- AMS). Over the three campaigns, the average mass con- centrations of the non-refractory submicron particles ranged from 10 µg m −3 up to 27 µg m −3 . Highest nitrate and ammo- nium mass concentrations were measured during the winter and during periods when marine modified airmasses were ar- riving at the site, whereas highest concentrations of organic particles were measured during the summer and during peri- ods when continental airmasses arrived at the site. The mea- surements reported in this paper show that atmospheric par- ticle composition is strongly influenced by both the season and the origin of the airmass. The total organic mass spectra were analysed using positive matrix factorisation to separate individual organic components contributing to the overall or- ganic particle mass concentrations. These organic compo- nents include a low volatility oxygenated organic aerosol par- ticle (LV-OOA) and a semi-volatile organic aerosol particle (SV-OOA). Correlations of the LV-OOA components with fragments of m/z 60 and m/z 73 (mass spectral markers of wood burning) during the winter campaign suggest that win- tertime LV-OOA are related to aged biomass burning emis- sions, whereas organic aerosol particles measured during the
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Aerosol plume transport and transformation in high spectral resolution lidar measurements and WRF-Flexpart simulations during the MILAGRO Field Campaign

Aerosol plume transport and transformation in high spectral resolution lidar measurements and WRF-Flexpart simulations during the MILAGRO Field Campaign

The Flexpart simulations of biomass burning do not show many particles for the small plume on the left. However, Fig. 3a shows that there was a fire just northwest of the flight leg. For the larger plume to the right, there is a weak sig- nal of a fire plume in the simulations, barely seen as light blue on the navy background. The emissions model identi- fied a small fire just south of the flight curtain (see Fig. 3a). In both cases, it is possible that the emissions estimates were too low for these fires and also that discrepancies in the trans- port direction were sufficient for the model to miss the bulk of the plume. In the middle of the figure, shown by the green ellipse, is a mixed plume of dust, biomass burning and urban aerosols. This plume came from the MCMA basin through the mountain gap and was then transported as an el- evated layer separated from the surface flow. In the simula- tions, the plume can be seen to be at the surface, below the green ellipse, because Flexpart transported it along terrain contours rather than at constant elevation. The separation of the flow passing over the basin rim will be discussed further in Sect. 4.3.
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Effects of the presence of microplastic particles in portuguese coastal waters and marine mussels

Effects of the presence of microplastic particles in portuguese coastal waters and marine mussels

Figure 1.1.1 - European plastics demand in the EU-27+N/CH by resin type in 2012 ............................................... 6 Figure 1.1.2 - World and European plastic production ............................................................................................ 7 Figure 1.1.3 - World Plastic Production changes between 2009 and 2012 by region. ............................................. 8 Figure 1.1.4 - Change in municipal solid waste composition in Kg of waste per capita .......................................... 8 Figure 1.1.5 - Municipal waste generated per capita, between 2001 and 2010 in Europe .................................... 9 Figure 1.1.6 - Municipal waste management in the EU-27 + Norway and Switzerland by years .......................... 10 Figure 1.2.1 – Mytilus galloprovincialis ................................................................................................................. 15 Figure 2.1.1 – Sampling sites on the Portuguese coast). ....................................................................................... 30 Figure 2.1.2 – Marine debris items collected in Portuguese beaches between 2011 and 2013. ........................... 34 Figure 2.1.3 – Average resin pellets (items m -2 ± SD) for different classes ........................................................... 36
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Seasonal characterization of submicron aerosol chemical composition and  organic aerosol sources in the southeastern United States: Atlanta,  Georgia,and Look Rock, Tennessee

Seasonal characterization of submicron aerosol chemical composition and organic aerosol sources in the southeastern United States: Atlanta, Georgia,and Look Rock, Tennessee

Average concentration of IEPOX-OA at JST and LRK in- creased during summer. At LRK, the average concentration of IEPOX-OA reached a maximum in summer, but its relative contribution to total OA mass was lower due to the increas- ing concentration of 91Fac. Concentrations of IEPOX-OA at both sites are comparable (Fig. 8), suggesting that in summer this factor may become spatially homogeneous in the south- eastern US. Since measurements at JST and LRK were con- ducted during different years, meteorological changes might play a role in site-to-site comparison. At LRK, IEPOX-OA showed a small increase around noon, while at JST there was a local maximum in the mid-afternoon, suggesting an influx of IEPOX-OA likely transported from surrounding forested areas. The time series of IEPOX-OA was moderately cor- related with nitrate (r 2 ∼ 0.4) at JST, and at LRK, stronger
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Aerosol analysis using a Proton-Transfer-Reaction Thermo-Desorption Mass Spectrometer (PTR-TD-MS): a new approach to study processing of organic aerosols

Aerosol analysis using a Proton-Transfer-Reaction Thermo-Desorption Mass Spectrometer (PTR-TD-MS): a new approach to study processing of organic aerosols

J., Donahue, N. M., George, C., Goldstein, A. H., Hamilton, J. F., Herrmann, H., Hoffmann, T., Iinuma, Y., Jang, M., Jenkin, M. E., Jimenez, J. L., Kiendler-Scharr, A., Maenhaut, W., McFiggans, G., Mentel, Th. F., Monod, A., Pr ´ev ˆot, A. S. H., Seinfeld, J. H., Surratt, J. D., Szmigielski, R., and Wildt, J.: The formation, properties and impact of secondary organic aerosol: current and emerging issues, Atmos. Chem. Phys., 9, 5155–5235, 2009,

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Simultaneous retrieval of aerosol and cloud properties during the MILAGRO field campaign

Simultaneous retrieval of aerosol and cloud properties during the MILAGRO field campaign

Fig. 2. The spatial context of our AAC scene is presented in this figure. The blue circle in- dicates the location of RSP observations, above a marine stratocumulus cloud on the Gulf of Mexico coast. A portion of the J-31 flight track is shown in yellow. The J-31 performed a spiral to the surface about 125 km northwest of the scene, and data collected during this descent provided information about cloud and aerosol vertical distribution. Aerosol sources include ur- ban/industrial emissions in the Mexico City Metropolitan Area (MCMA) basin, a high valley to the west, and numerous (mostly agricultural) fires indicated by the red fire icons. Fire locations were identified by the MODIS active fire product and represent fires within the previous eight days. The MODIS Terra instrument captured the underlying image.
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Relating particle hygroscopicity and CCN activity to chemical composition during the HCCT-2010 field campaign

Relating particle hygroscopicity and CCN activity to chemical composition during the HCCT-2010 field campaign

temporal variability of particle hygroscopic growth. Gener- ally, GF-PDFs show two distinct modes: hydrophobic mode (HGF < 1.2) and hydrophilic mode (HGF > 1.2). This indi- cates that the aerosols are usually externally mixed. However, occasionally the number fraction of hydrophilic mode (F2 in Fig. 1) is close to 1 for particle sizes greater than 100 nm. No matter what particle size is considered, the hydrophilic mode is always more prominent in the GF-PDF. With in- creasing particle size, the dominance of hydrophilic mode becomes more pronounced. The mean number fractions of the hydrophilic mode for 50, 100, 150, 200, 250 nm particles are respectively 0.64, 0.72, 0.80, 0.84, and 0.86. The rea- son is that larger particles have undergone atmospheric ag- ing processes (coagulation, condensation, chemical reaction, cloud processing) (P¨oschl, 2005) for a longer time compared to smaller particles. These aging processes typically enhance the water solubility of particles (P¨oschl, 2005; Jimenez et al., 2009).
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The quality of castings obtained during lost-wax and Replicast CS processes in aspect of ecology

The quality of castings obtained during lost-wax and Replicast CS processes in aspect of ecology

Haratym, Dok ł adno ć wymiarowa odlewów wykona- nych w procesie Replicast CS, Archiwum Odlewnictwa rocznik 3, nr 9, Katowice 2003.. Arendarski, Niepewno ć pomiarów, Oficyna Wydaw- nic[r]

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Hygroscopicity and chemical composition of Antarctic sub-micrometre aerosol particles and observations of new particle formation

Hygroscopicity and chemical composition of Antarctic sub-micrometre aerosol particles and observations of new particle formation

Organic and elemental carbon (OC and EC) samples of below 1 µm particles were collected using two quartz fiber filters (Whatman Q-MA 47 mm) placed in series in a filter cassette system (Gelman Sciences). Prior to the sampling, the quartz filters were cleaned at 550 ◦ C for six hours. In order to collect the submicrometre particle size fraction of PM only (aerodynamic particle diameter <1 µm, PM 1 ), the four upper stages

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Sources and production of organic aerosol in Mexico City: insights from the combination of a chemical transport model (PMCAMx-2008) and measurements during MILAGRO

Sources and production of organic aerosol in Mexico City: insights from the combination of a chemical transport model (PMCAMx-2008) and measurements during MILAGRO

The values of the OA concentrations at the boundaries of the domain, approximately 8 µg m −3 in the west, 11.5 µg m −3 in the east, 7 µg m −3 in the south and 5 µg m −3 in the north- ern boundary, were chosen based on results of the GISS- II’ global CTM for March (Racherla and Adams, 2006). All concentrations in this paper are under ambient pressure and temperature conditions. These levels represent the av- erage OA concentrations over the Central Mexican Plateau approximately 100 km outside Mexico City and should not be confused with the larger-scale background concentrations of Mexico (reflecting concentrations over the lower to mid- dle troposphere over the Pacific Ocean) of much less than 0.5 µg m −3 (DeCarlo et al., 2008; Fast et al., 2009). 32 % of the OA concentration at the boundaries of the domain is assumed to be 0.04–0.08 µm in size, 24 % is the 0.08– 0.16 µm range, 20 % from 0.16 to 0.31 µm, 12 % from 0.31 to 0.625 µm, 8 % from 0.625 to 1.25 µm, and 4 % in the 1.25– 2.5 µm range. Because the biomass burning emissions are not included in the current inventory, they are implicitly provided to the model as a part of the boundary conditions. These rel- atively high boundary condition values are consistent with the findings of Yokelson et al. (2007) suggesting that the fires in the mountainous forests around Mexico City (MC) could produce as much as 80–90 % of the primary fine parti- cle mass in the MC area. DeCarlo et al. (2010) reported that OA arising from open BB represents around 65 % of the OA mass in the basin and contributes similarly to OA mass in the outflow. Crounse et al. (2009) estimated that biomass burn- ing contributed two thirds of the organic aerosol to the study area in March 2006. Subsequent atmospheric oxidation of co-emitted hydrocarbons can yield low vapor pressure com- pounds that condense on the existing particulate forming sec- ondary organic aerosol. Therefore, the organic mass trans- ported into the domain is assumed to be a mixture of aged pri- mary and secondary organic aerosols, and is referred to here- after as “long range transport oxygenated OA” (LT-OOA). The model assumes that V-SOA, I-SOA and S-SOA form a pseudo-ideal solution together with the LT-OOA, which are assumed to be non-reactive and nonvolatile, and therefore, are allowed to partition into this pre-existing organic aerosol.
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Relating particle hygroscopicity and CCN activity to chemical composition during the HCCT-2010 field campaign

Relating particle hygroscopicity and CCN activity to chemical composition during the HCCT-2010 field campaign

Hallquist, M., Wenger, J. C., Baltensperger, U., Rudich, Y., Simpson, D., Claeys, M., Dom- men, J., Donahue, N. M., George, C., Goldstein, A. H., Hamilton, J. F., Herrmann, H., Hoff- mann, T., Iinuma, Y., Jang, M., Jenkin, M. E., Jimenez, J. L., Kiendler-Scharr, A., Maen- haut, W., McFiggans, G., Mentel, Th. F., Monod, A., Pr ´ev ˆot, A. S. H., Seinfeld, J. H., Sur- ratt, J. D., Szmigielski, R., and Wildt, J.: The formation, properties and impact of sec-

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Modeling organic aerosol composition at the puy de Dôme mountain (France) for two contrasted air masses with the WRF-Chem model

Modeling organic aerosol composition at the puy de Dôme mountain (France) for two contrasted air masses with the WRF-Chem model

son, D., Sun, J. Y., Topping, D., Tunved, P., Vaattovaara, P., Vakkari, V., Veefkind, J. P., Viss- chedijk, A., Vuollekoski, H., Vuolo, R., Wehner, B., Wildt, J., Woodward, S., Worsnop, D. R., van Zadelhoff, G.-J., Zardini, A. A., Zhang, K., van Zyl, P. G., Kerminen, V.-M., S Carslaw, K., and Pandis, S. N.: General overview: European Integrated project on Aerosol Cloud Climate and Air Quality interactions (EUCAARI) – integrating aerosol research from nano to global

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Decadal trends in aerosol chemical composition at Barrow, Alaska: 1976–2008

Decadal trends in aerosol chemical composition at Barrow, Alaska: 1976–2008

is beyond the scope of this paper to attribute these increasing trends to particular factors, the ice core results suggest that they may be due to recent decreases in sea-ice cover and in- creases in mean sea surface temperature (SST). Further work is required to link the observed trends at Barrow to changing environmental factors. Particle number concentrations are highest at Barrow and other surface Arctic sites during the summer (Quinn et al., 2002; Engvall et al., 2008) suggest- ing a link between biogenic activity and enhanced particle production. The climatic importance of the biogenically pro- duced particles at Barrow, in terms of their ability to act as cloud condensation nuclei, is yet to be determined.
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Decadal trends in aerosol chemical composition at Barrow, AK: 1976–2008

Decadal trends in aerosol chemical composition at Barrow, AK: 1976–2008

be used at cold temperatures. NcMn in the atmosphere results from a wider variety of anthropogenic activities including iron, steel, and ferro-alloy manufacturing; coal com- bustion; oil combustion; and mining (Pacyna et al., 1984). Rahn (1981) reported that the wintertime ncMn to ncV ratio was a factor of 5 higher in aerosol originating from Eu- rope than from the northeast US. The higher ratios measured in Europe were attributed

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The Impact of the Expansion of the Bolsa Familia Program on the Time Allocation of Youths And Their Parents Lia Chitolina Miguel Nathan Foguel Naercio Menezes-Filho

The Impact of the Expansion of the Bolsa Familia Program on the Time Allocation of Youths And Their Parents Lia Chitolina Miguel Nathan Foguel Naercio Menezes-Filho

As the multinomial model is non-linear, the marginal effect of the treatment in a DID model is not the marginal impact of the interaction between time and treatment, but the difference of the cross-differences, as described by Puhani (2012). The results of Table 7 (in terms of marginal effects) show that the BVJ has a significant effect on the probability studying and working at the same time, but not on the other outcome variables. The estimated marginal effects mean that the probability of a youngster studying and working increases by 4.2 percentage points with the BVJ, compared with a baseline of 30% in the control group in 2006. The estimated coefficients for the categories ‘studying only’ and ‘working only’ were negative but not statistically significant. It seems, therefore, that treated adolescents do not quit their jobs to study because of the program, but do both activities at the same time. This raises questions about the long run impacts of the program, since the quality of the night classes is notoriously low in Brazil.
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Overview of aerosol properties associated with air masses sampled by the ATR-42 during the EUCAARI campaign (2008)

Overview of aerosol properties associated with air masses sampled by the ATR-42 during the EUCAARI campaign (2008)

Res, J. G., Schwarz, J. P., Gao, R. S., Fahey, D. W., Thomson, D. S., Watts, L. A., Wilson, J. C., Reeves, J. M., Darbeheshti, M., Baumgardner, D. G., Kok, G. L., Chung, S. H., Schulz, M., Hendricks, J., Lauer, A., Karcher, B., Slowik, J. G., Rosenlof, K. H., Thompson, T. L., Lang- ford, A. O., Loewenstein, M., and Aikin, K. C.: Single-particle measurements of midlatitude black carbon and light-scattering aerosols from the boundary layer to the lower stratosphere,

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Chemical composition of aerosol collected in the amazon forest.

Chemical composition of aerosol collected in the amazon forest.

CHEMICAL COMPOSITION OF AEROSOL COLLECTED IN THE AMAZON FOREST. It was identified and quantified several organic compounds in the atmosphere of a site into Amazon Basin with high impact of biomass burning emission. It was important to know the particulate matter composition with respect to n-alkanes and PAH associated with the particulate matter because they provided indication on the main sources contributing to airborne particles, the con- tribution of natural vs. man-made emission and the aging of the particles. The main classes of compounds observed were n-alkanes, PAH and nitro-PAH. It was observed the formation of nitro- PAH from photochemical reactions. The aerosol mass concentration is mainly associated with fluoranthene, pyrene and benzo(ghi)perylene. Environmental and direct emissions samples (flam- ing and smoldering) were collected and analysed.
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