scholarly journals Cloud condensation nuclei activity at Jeju Island, Korea in spring 2005

2008 ◽  
Vol 8 (11) ◽  
pp. 2933-2948 ◽  
Author(s):  
M. Kuwata ◽  
Y. Kondo ◽  
Y. Miyazaki ◽  
Y. Komazaki ◽  
J. H. Kim ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Temporal Variation ◽  
Cloud Condensation Nuclei ◽  
Particle Diameter ◽  
Inorganic Ions ◽  
Water Soluble ◽  
Jeju Island ◽  
Chemical Compositions ◽  
Condensation Nuclei ◽  
Soluble Components

Abstract. We measured the number concentrations of cloud condensation nuclei (CCN) and the size distributions of CCN/CN (CN: condensation nuclei) ratios at supersaturations (SSs) of 0.097, 0.27, 0.58, and 0.97% at Jeju Island, Korea during March-April 2005. We made simultaneous measurements of aerosol inorganic ions, water-soluble organic carbon (WSOC), organic carbon (OC), and elemental carbon (EC) in PM2.5. The CCN/CN ratios increased with increasing particle diameter, and the diameter at CCN/CN=0.5 was defined as D50. D50 represents the activation dry diameter of atmospheric particles. The average D50 at SS=0.097% and 0.97% was 136±17 nm and 31±3 nm, respectively. The temporal variation of D50 at SS=0.097% was correlated with the mass fraction of water-soluble components (inorganic ions + WSOC), indicating that the temporal variation of CCN activity was mainly controlled by changes in the water-soluble components fraction. The critical dry diameter (Dcrit), which is the threshold dry diameter for CCN activation, was calculated from the observed aerosol chemical compositions by Köhler theory for comparison with D50. The D50 at SS=0.097% was correlated (r2=0.48) with calculated Dcrit, although Dcrit was larger than D50 by 20–29% on average. The systematic difference between D50 and Dcrit could be caused by the size dependence of the aerosol chemical compositions or surface tension lowering caused by the mixing of water-soluble organic compounds. This difference corresponds to a 27±14% uncertainty in the CCN number concentration estimated from the observed particle number size distribution.

scholarly journals Cloud condensation nuclei activity at Jeju Island, Korea in spring 2005

2007 ◽  
Vol 7 (6) ◽  
pp. 15805-15851 ◽  
Author(s):  
M. Kuwata ◽  
Y. Kondo ◽  
Y. Miyazaki ◽  
Y. Komazaki ◽  
J. H. Kim ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Temporal Variation ◽  
Cloud Condensation Nuclei ◽  
Particle Diameter ◽  
Inorganic Ions ◽  
Water Soluble ◽  
Jeju Island ◽  
Chemical Compositions ◽  
Condensation Nuclei ◽  
Soluble Components

Abstract. We measured the number concentrations of cloud condensation nuclei (CCN) and the size distributions of CCN/CN (CN: condensation nuclei) ratios at supersaturations (SSs) of 0.097, 0.27, 0.58, and 0.97% at Jeju-Island, Korea during March-April 2005. Measurements of aerosol inorganic ions, water-soluble organic carbon (WSOC), organic carbon (OC), and elemental carbon (EC) in PM2.5 were simultaneously made. The CCN/CN ratios increased with increasing particle diameter, and the diameter at CCN/CN=0.5 was defined as D50. D50 represents the activation dry diameter of atmospheric particles. The average D50 at SS=0.097% and 0.97% was 136 nm and 31 nm, respectively. The temporal variation of D50 at SS=0.097% was correlated with the mass fraction of water-soluble components (inorganic ions + WSOC), indicating that the temporal variation of CCN activity was mainly controlled by changes in the water-soluble components fraction. The critical dry diameter (Dcrit), which is the threshold dry diameter for CCN activation, was calculated from the observed aerosol chemical compositions by Köhler theory for comparison with D50. The D50 at SS=0.097% was correlated (r2=0.48) with calculated Dcrit, although Dcrit were larger than D50 by 20–29% on average. The systematic difference between D50 and Dcrit could be caused by the size dependence of the aerosol chemical compositions or surface tension lowering caused by the mixing of water-soluble organic compounds. This difference corresponds to a 27±14% uncertainty in the CCN number concentration estimated from the observed particle number size distribution.

scholarly journals Characteristics of concentrations and chemical compositions for PM<sub>2.5</sub> in the region of Beijing, Tianjin, and Hebei, China

2013 ◽  
Vol 13 (9) ◽  
pp. 4631-4644 ◽  
Author(s):  
P. S. Zhao ◽  
F. Dong ◽  
D. He ◽  
X. J. Zhao ◽  
X. L. Zhang ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Coal Combustion ◽  
Urban Areas ◽  
Motor Vehicle ◽  
Inorganic Ions ◽  
Water Soluble ◽  
Photochemical Oxidation ◽  
Chemical Compositions ◽  
Coal Consumption ◽  
Water Soluble Inorganic Ions

Abstract. In order to study the temporal and spatial variations of PM2.5 and its chemical compositions in the region of Beijing, Tianjin, and Hebei (BTH), PM2.5 samples were collected at four urban sites in Beijing (BJ), Tianjin (TJ), Shijiazhuang (SJZ), and Chengde (CD), and also one site at Shangdianzi (SDZ) regional background station over four seasons from 2009 to 2010. The samples were weighted for mass concentrations and analyzed in the laboratory for chemical profiles of 19 elements (Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Ni, P, Pb, Sr, Ti, V, and Zn), eight water-soluble inorganic ions (Na+, NH4+, K+, Mg2+, Ca2+, Cl−, NO3−, and SO42−, and carbon fractions (OC and EC). The concentrations of PM2.5 and its major chemical species were season dependent and showed spatially similar characteristics in the plain area of BTH. The average annual concentrations of PM2.5 were 71.8–191.2 μg m−3 at the five sites, with more than 90% of sampling days exceeding 50 μg m−3 at BJ, TJ, and SJZ. PM2.5 pollution was most serious at SJZ, and the annual concentrations of PM2.5, secondary inorganic ions, OC, EC, and most crustal elements were all highest. Due to stronger photochemical oxidation, the sum of concentrations of secondary inorganic ions (NH4+, NO3−, and SO42− was highest in the summer at SDZ, BJ, TJ, and CD. Analysis of electric charges of water-soluble inorganic ions indicated the existence of nitric acid or hydrochloric acid in PM2.5. For all five sites, the concentrations of OC, EC and also secondary organic carbon (SOC) in the spring and summer were lower than those in the autumn and winter. SOC had more percentages of increase than primary organic carbon (POC) during the winter. The sums of crustal elements (Al, Ca, Fe, Mg, Ti, Ba, and Sr) were higher in the spring and autumn owing to more days with blowing or floating dust. The concentrations of heavy metals were at higher levels in the BTH area by comparison with other studies. In Shijiazhuang and Chengde, the PM2.5 pollution was dominated by coal combustion. Motor vehicle exhausts and coal combustion emissions both played important roles in Tianjin PM2.5 pollution. However, motor vehicle exhausts had played a more important role in Beijing owing to the reduction of coal consumption and sharp increase of cars in recent years. At SDZ, regional transportation of air pollutants from southern urban areas was significant.

scholarly journals Hygroscopic properties and cloud condensation nuclei activation of limonene-derived organosulfates and their mixtures with ammonium sulfate

2015 ◽  
Vol 15 (24) ◽  
pp. 14071-14089 ◽  
Author(s):  
A. M. K. Hansen ◽  
J. Hong ◽  
T. Raatikainen ◽  
K. Kristensen ◽  
A. Ylisirniö ◽  
...  
Keyword(s):  
Surface Tension ◽  
Ammonium Sulfate ◽  
Cloud Condensation Nuclei ◽  
Pure Water ◽  
Particle Diameter ◽  
Droplet Surface ◽  
Chemical Compositions ◽  
Condensation Nuclei ◽  
Hygroscopic Properties ◽  
Wide Range

Abstract. Organosulfates have been observed as constituents of atmospheric aerosols in a wide range of environments; however their hygroscopic properties remain uncharacterised. Here, limonene-derived organosulfates with a molecular weight of 250 Da (L-OS 250) were synthesised and used for simultaneous measurements with a hygroscopicity tandem differential mobility analyser (H-TDMA) and a cloud condensation nuclei counter (CCNC) to determine the hygroscopicity parameter, κ, for pure L-OS 250 and mixtures of L-OS 250 with ammonium sulfate (AS) over a wide range of humidity conditions. The κ values derived from measurements with H-TDMA decreased with increasing particle dry diameter for all chemical compositions investigated, indicating that κH-TDMA depends on particle diameter and/or surface effects; however, it is not clear if this trend is statistically significant. For pure L-OS 250, κ was found to increase with increasing relative humidity, indicating dilution/solubility effects to be significant. Discrepancies in κ between the sub- and supersaturated measurements were observed for L-OS 250, whereas κ of AS and mixed L-OS 250/AS were similar. This discrepancy was primarily ascribed to limited dissolution of L-OS 250 at subsaturated conditions. In general, hygroscopic growth factor, critical particle diameter and κ for the mixed L-OS 250/AS particles converged towards the values of pure AS for mixtures with ≥ 20 % w / w AS. Surface tension measurements of bulk aqueous L-OS 250/AS solutions showed that L-OS 250 was indeed surface active, as expected from its molecular structure, decreasing the surface tension of solutions with 24 % from the pure water value at a L-OS 250 concentration of 0.0025 mol L−1. Based on these surface tension measurements, we present the first concentration-dependent parametrisation of surface tension for aqueous L-OS 250, which was implemented to different process-level models of L-OS 250 hygroscopicity and CCN activation. The values of κ obtained from the measurements were compared with κ calculated applying the volume additive Zdanovskii–Stokes–Robinson mixing rule, as well as κ modelled from equilibrium Köhler theory with different assumptions regarding L-OS 250 bulk-to-surface partitioning and aqueous droplet surface tension. This study is to our knowledge the first to investigate the hygroscopic properties and surface activity of L-OS 250; hence it is an important first step towards understanding the atmospheric impact of organosulfates.

scholarly journals Organic and inorganic markers and stable C-, N-isotopic compositions of tropical coastal aerosols from megacity Mumbai: sources of organic aerosols and atmospheric processing

2012 ◽  
Vol 12 (8) ◽  
pp. 20593-20630 ◽  
Author(s):  
S. G. Aggarwal ◽  
K. Kawamura ◽  
G. S. Umarji ◽  
E. Tachibana ◽  
R. S. Patil ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Biomass Burning ◽  
Winter Season ◽  
Organic Aerosols ◽  
Inorganic Ions ◽  
Water Soluble ◽  
Total Carbon ◽  
Chemical Compositions ◽  
Diurnal Changes ◽  
Positive Correlation

Abstract. To better understand the sources of PM10 samples from Mumbai, India, aerosol chemical compositions, i.e. total carbon (TC), organic carbon (OC), elemental carbon (EC), water-soluble organic carbon (WSOC), and inorganic ions were studied together with specific markers such as methanesulfonate (MSA), oxalic acid (C2), azelaic acid (C9), and levoglucosan. The results revealed that biofuel/biomass burning and fossil fuel combustion are the major sources of the Mumbai aerosols. Nitrogen-isotopic (δ15N) composition of aerosol total nitrogen, which ranged from 18.1 to 25.4‰, also suggest that biofuel/biomass burning is the dominant source in both summer and winter seasons. Aerosol mass concentrations of major species increased 3–4 times in winter compared to summer, indicating an enhanced emission from these sources in winter season. Photochemical production tracers, C2 diacid and nssSO42− do not show diurnal changes. Concentrations of C2 diacid and WSOC show a strong correlation (r2 = 0.95). In addition, WSOC to OC (or TC) ratios remain almost constant for day- (0.37 ± 0.06 (0.28 ± 0.04)) and nighttime (0.38 ± 0.07 (0.28 ± 0.06)), suggesting that mixing of fresh secondary organic aerosols is not significant rather the Mumbai aerosols are photochemically well processed. Concentrations of MSA and C9 diacid present a positive correlation (r2 = 0.75), indicating a marine influence on Mumbai aerosols in addition to local/regional influence. Backward air mass trajectory analyses further suggested that the Mumbai aerosols are largely influenced by long-range continental and regional transport. Stable C-isotopic ratios (δ13C) of TC ranged from −27.0 to −25.4‰ with slightly lower average (−26.5 ± 0.3‰) in summer than in winter (−25.9 ± 0.3‰). Positive correlation between WSOC/TC ratios and δ13C values suggested that the increment in δ13C of wintertime TC may be caused by prolonged photochemical processing of organic aerosols in this season. This study suggests that in winter, the tropical aerosols are more aged due to longer residence time in the atmosphere than in the summer aerosols.

scholarly journals Summertime observations of ultrafine particles and cloud condensation nuclei from the boundary layer to the free troposphere in the Arctic

2016 ◽  
Author(s):  
Julia Burkart ◽  
Megan D. Willis ◽  
Heiko Bozem ◽  
Jennie L. Thomas ◽  
Kathy Law ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Ultrafine Particles ◽  
Cloud Condensation Nuclei ◽  
Particle Diameter ◽  
Open Ocean ◽  
The Arctic ◽  
Condensation Nuclei ◽  
Aerosol Composition ◽  
Low Level ◽  
20 Nm

Abstract. The Arctic is extremely sensitive to climate change. Shrinking sea ice extent increases the area covered by open ocean during Arctic summer, which impacts the surface albedo and aerosol and cloud properties among many things. In this context extensive aerosol measurements (aerosol composition, particle number and size, cloud condensation nuclei, and trace gases) were made during 11 flights of the NETCARE July, 2014 airborne campaign conducted from Resolute Bay, Nunavut (74N, 94W). Flights routinely included vertical profiles from about 60 to 3000 m a.g.l. as well as several low-level horizontal transects over open ocean, fast ice, melt ponds, and polynyas. Here we discuss the vertical distribution of ultrafine particles (UFP, particle diameter, dp: 5–20 nm), size distributions of larger particles (dp: 20 nm to 1 μm), and cloud condensation nuclei (CCN, supersaturation = 0.6 %) in relation to meteorological conditions and underlying surfaces. UFPs were observed predominantly within the boundary layer, where concentrations were often several hundreds to a few thousand particles per cubic centimeter. Occasionally, particle concentrations below 10 cm−3 were found. The highest UFP concentrations were observed above open ocean and at the top of low-level clouds, whereas numbers over ice-covered regions were substantially lower. Overall, UFP formation events were frequent in a clean boundary layer with a low condensation sink. In a few cases this ultrafine mode extended to sizes larger than 40 nm, suggesting that these UFP can grow into a size range where they can impact clouds and therefore climate.

scholarly journals Contents, distribution, and fractionation of soil organic carbon and trace elements in soils under a green manure application

2020 ◽  
Vol 16 (No. 1) ◽  
pp. 50-58
Author(s):  
Yana Timofeeva ◽  
Lyudmila Purtova ◽  
Alexey Emelyanov ◽  
Maxim Burdukovskii ◽  
Irina Kiseleva ◽  
...  
Keyword(s):  
Trace Elements ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Green Manure ◽  
Mineral Soil ◽  
Water Soluble ◽  
Household Waste ◽  
Nickel Ions ◽  
Low Degree ◽  
Soluble Components

We quantified the soluble fractions of the soil organic carbon (SOC) concentrations and the total and water-soluble trace elements in soils contaminated by household waste and remediated via the addition of green manure over 13 years and identified the main factors controlling the vertical distribution and accumulation of the trace elements. Green manure favoured the active formation of soil organic matter. The SOC of the examined soils was characterised by the active stabilisation by mineral soil compounds, but by a low degree of humification. The soils showed increased concentrations of Cr and Ni ions. The SOC and different soil compounds enriched by Si, Ca, and Mn ions were the important determinant for the distribution of Sr, V and Cu ions, as well as for the distribution of Pb and Cr ions bound to the water-soluble components of the soils. The low degree of SOC humification may be one of the main reasons of the high concentrations of Cu and Pb ions in the composition of the water-soluble soil compounds. The nickel ions were mainly associated with compounds enriched by the Al and Fe ions. The extremely high percentage concentration of the Ni ions in the water-soluble components of the soils may be result of the absence of the Ni ions adsorption by humic substances.

scholarly journals Organic acids as cloud condensation nuclei: Laboratory studies of highly soluble and insoluble species

2003 ◽  
Vol 3 (1) ◽  
pp. 949-982 ◽  
Author(s):  
P. Pradeep Kumar ◽  
K. Broekhuizen ◽  
J. P. D. Abbatt
Keyword(s):  
Organic Acids ◽  
Room Temperature ◽  
Cloud Condensation Nuclei ◽  
Particle Diameter ◽  
Diffusion Chamber ◽  
Laboratory Studies ◽  
Condensation Nuclei ◽  
Gradient Diffusion ◽  
Kohler Theory ◽  
Good Agreement

Abstract. The ability of sub-micron-sized organic acid particles to act as cloud condensation nuclei (CCN) has been examined at room temperature using a newly constructed continuous-flow, thermal-gradient diffusion chamber (TGDC). The organic acids studied were: oxalic, malonic, glutaric, oleic and stearic. The CCN properties of the highly soluble acids – oxalic, malonic and glutaric – match very closely Kohler theory predictions which assume full dissolution of the dry particle and a surface tension of the growing droplet equal to that of water. In particular, for supersaturations between 0.3 and 0.6, agreement between the dry particle diameter which gives 50% activation and that calculated from Kohler theory is to within 3 nm on average. In the course of the experiments, considerable instability of glutaric acid particles was observed as a function of time and there is evidence that they fragment to some degree to smaller particles. Stearic acid and oleic acid, which are both highly insoluble in water, did not activate at supersaturations of 0.6% with dry diameters up to 140 nm. Finally, to validate the performance of the TGDC, we present results for the activation of ammonium sulfate particles that demonstrate good agreement with Kohler theory if solution non-ideality is considered. Our findings support earlier studies in the literature that showed highly soluble organics to be CCN active but insoluble species to be largely inactive.

scholarly journals Characteristics of PM2.5 Chemical Compositions and Their Effect on Atmospheric Visibility in Urban Beijing, China during the Heating Season

2018 ◽  
Vol 15 (9) ◽  
pp. 1924 ◽  
Author(s):  
Xing Li ◽  
Shanshan Li ◽  
Qiulin Xiong ◽  
Xingchuan Yang ◽  
Mengxi Qi ◽  
...  
Keyword(s):  
Fine Particles ◽  
Inorganic Ions ◽  
Water Soluble ◽  
Motor Vehicles ◽  
Urban Site ◽  
Chemical Compositions ◽  
Heating Season ◽  
Atmospheric Visibility ◽  
Visibility Impairment ◽  
Mass Concentrations

Beijing, which is the capital of China, suffers from severe Fine Particles (PM2.5) pollution during the heating season. In order to take measures to control the PM2.5 pollution and improve the atmospheric environmental quality, daily PM2.5 samples were collected at an urban site from 15 November to 31 December 2016, characteristics of PM2.5 chemical compositions and their effect on atmospheric visibility were analyzed. It was found that the daily average mass concentrations of PM2.5 ranged from 7.64 to 383.00 μg m−3, with an average concentration of 114.17 μg m−3. On average, the Organic Carbon (OC) and Elemental Carbon (EC) contributed 21.39% and 5.21% to PM2.5, respectively. Secondary inorganic ions (SNA: SO42− + NO3− + NH4+) dominated the Water-Soluble Inorganic Ions (WSIIs) and they accounted for 47.09% of PM2.5. The mass concentrations of NH4+, NO3− and SO42− during the highly polluted period were 8.08, 8.88 and 6.85 times greater, respectively, than during the clean period, which contributed most to the serious PM2.5 pollution through the secondary transformation of NO2, SO2 and NH3. During the highly polluted period, NH4NO3 contributed most to the reconstruction extinction coefficient (b′ext), accounting for 35.7%, followed by (NH4)2SO4 (34.44%) and Organic Matter (OM: 15.24%). The acidity of PM2.5 in Beijing was weakly acid. Acidity of PM2.5 and relatively high humidity could aggravate PM2.5 pollution and visibility impairment by promoting the generation of secondary aerosol. Local motor vehicles contributed the most to NO3−, OC, and visibility impairment in urban Beijing. Other sources of pollution in the area surrounding urban Beijing, including coal burning, agricultural sources, and industrial sources in the Hebei, Shandong, and Henan provinces, released large amounts of SO2, NH3, and NO2. These, which were transformed into SO42−, NH4+, and NO3− during the transmission process, respectively, and had a great impact on atmospheric visibility impairment.

scholarly journals Cloud condensation nuclei measurements in the marine boundary layer of the Eastern Mediterranean: CCN closure and droplet growth kinetics

2009 ◽  
Vol 9 (18) ◽  
pp. 7053-7066 ◽  
Author(s):  
A. Bougiatioti ◽  
C. Fountoukis ◽  
N. Kalivitis ◽  
S. N. Pandis ◽  
A. Nenes ◽  
...  
Keyword(s):  
Size Distribution ◽  
Growth Kinetics ◽  
Eastern Mediterranean ◽  
Cloud Condensation Nuclei ◽  
Bulk Composition ◽  
Organic Content ◽  
Water Soluble ◽  
Aerosol Size Distribution ◽  
Droplet Growth ◽  
Condensation Nuclei

Abstract. Measurements of cloud condensation nuclei (CCN) concentrations (cm−3) between 0.2 and 1.0% supersaturation, aerosol size distribution and chemical composition were performed at a remote marine site in the eastern Mediterranean, from September to October 2007 during the FAME07 campaign. Most of the particles activate at ~0.6% supersaturation, characteristic of the aged nature of the aerosol sampled. Application of Köhler theory, using measurements of bulk composition, size distribution, and assuming that organics are insoluble resulted in agreement between predicted and measured CCN concentrations within 7±11% for all supersaturations, with a tendency for CCN underprediction (16±6%; r2=0.88) at the lowest supersaturations (0.21%). Including the effects of the water-soluble organic fraction (which represent around 70% of the total organic content) reduces the average underprediction bias at the low supersaturations, resulting in a total closure error of 0.6±6%. Using threshold droplet growth analysis, the growth kinetics of ambient CCN is consistent with NaCl calibration experiments; hence the presence of aged organics does not suppress the rate of water uptake in this environment. The knowledge of the soluble salt fraction is sufficient for the description of the CCN activity in this area.

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