scholarly journals Hygroscopic properties and CCN activity of atmospheric aerosols under the influences of Asian continental outflow and new particle formation at a coastal site in East Asia

2019 ◽  
Author(s):  
Hing Cho Cheung ◽  
Charles C.-K. Chou ◽  
Celine S. L. Lee ◽  
Wei-Chen Kuo ◽  
Shuenn-Chin Chang
Keyword(s):  
Chemical Composition ◽  
Atmospheric Aerosols ◽  
Cloud Condensation Nuclei ◽  
Northern China ◽  
Particle Formation ◽  
Number Concentration ◽  
New Particle Formation ◽  
Air Masses ◽  
Hygroscopic Properties ◽  
Ccn Activity

Abstract. The chemical composition of fine particulate matters (PM2.5), the size distribution and number concentration of aerosol particles (NCN) and the number concentration of cloud condensation nuclei (NCCN) were measured at the northern tip of Taiwan Island during a campaign from April 2017 to March 2018. The parameters of aerosol hygroscopicity (i.e. activation ratio, activation diameter and kappa) were retrieved from the measurements. Significant variations were found in the hygroscopicity of aerosols, which were suggested be subject to various pollution sources, including aged air pollutants originating in the eastern/northern China and transported on the Asian continental outflows, fresh particles emitted from local sources and distributed by land-sea breeze circulations as well as produced by new particle formation (NPF) processes. Cluster analysis was applied to the backward trajectories of air masses to investigate their respective source regions. The results showed that the aerosols associated with Asian continental outflows were characterized with higher kappa values, whereas higher NCCN and NCN with lower kappa values were found for aerosols in local air masses. The distinct features in hygroscopicity were consistent with the characteristics in the chemical composition of PM2.5. Moreover, this study revealed that the nucleation mode particles from NPF could have participated in the enhancement of CCN activity, most likely by coagulating with sub-CCN particles, although the freshly produced particles were not favored for CCN activation due to their smaller sizes. Thus, the results of this study suggested that the NPF coupling with coagulation processes can significantly increase the NCCN in atmosphere.

scholarly journals Hygroscopic properties and cloud condensation nuclei activity of atmospheric aerosols under the influences of Asian continental outflow and new particle formation at a coastal site in eastern Asia

2020 ◽  
Vol 20 (10) ◽  
pp. 5911-5922 ◽  
Author(s):  
Hing Cho Cheung ◽  
Charles Chung-Kuang Chou ◽  
Celine Siu Lan Lee ◽  
Wei-Chen Kuo ◽  
Shuenn-Chin Chang
Keyword(s):  
Chemical Composition ◽  
Cloud Condensation Nuclei ◽  
Particle Formation ◽  
Number Concentration ◽  
Pollution Sources ◽  
New Particle Formation ◽  
Condensation Nuclei ◽  
Air Masses ◽  
Hygroscopic Properties ◽  
Aerosol Hygroscopicity

Abstract. The chemical composition of fine particulate matter (PM2.5), the size distribution and number concentration of aerosol particles (NCN), and the number concentration of cloud condensation nuclei (NCCN) were measured at the northern tip of Taiwan during an intensive observation experiment from April 2017 to March 2018. The parameters of aerosol hygroscopicity (i.e., activation ratio, activation diameter and kappa of CCN) were retrieved from the measurements. Significant variations were found in the hygroscopicity of aerosols (kappa – κ – of 0.18–0.56, for water vapor supersaturation – SS – of 0.12 %–0.80 %), which were subject to various pollution sources, including aged air pollutants originating in eastern and northern China and transported by the Asian continental outflows and fresh particles emitted from local sources and distributed by land–sea breeze circulations as well as produced by processes of new particle formation (NPF). Cluster analysis was applied to the back trajectories of air masses to investigate their respective source regions. The results showed that aerosols associated with Asian continental outflows were characterized by lower NCN and NCCN values and by higher kappa values of CCN, whereas higher NCN and NCCN values with lower kappa values of CCN were observed in the aerosols associated with local air masses. Besides, it was revealed that the kappa value of CCN exhibited a decrease during the early stage of an event of new particle formation, which turned to an increasing trend over the later period. The distinct features in the hygroscopicity of aerosols were found to be consistent with the characteristics in the chemical composition of PM2.5. This study has depicted a clear seasonal characteristic of hygroscopicity and CCN activity under the influence of a complex mixture of pollutants from different regional and/or local pollution sources. Nevertheless, the mixing state and chemical composition of the aerosols critically influence the aerosol hygroscopicity, and further investigations are necessary to elucidate the atmospheric processing involved in the CCN activation in coastal areas.

scholarly journals The influence of chemical composition and mixing state of Los Angeles urban aerosol on CCN number and cloud properties

2008 ◽  
Vol 8 (18) ◽  
pp. 5649-5667 ◽  
Author(s):  
M. J. Cubison ◽  
B. Ervens ◽  
G. Feingold ◽  
K. S. Docherty ◽  
I. M. Ulbrich ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Los Angeles ◽  
Cloud Condensation Nuclei ◽  
Number Concentration ◽  
The State ◽  
Urban Aerosol ◽  
Mixing State ◽  
Data Set ◽  
Hygroscopic Properties ◽  
Aerosol Distribution

Abstract. The relationship between cloud condensation nuclei (CCN) number and the physical and chemical properties of the atmospheric aerosol distribution is explored for a polluted urban data set from the Study of Organic Aerosols at Riverside I (SOAR-1) campaign conducted at Riverside, California, USA during summer 2005. The mixing state and, to a lesser degree, the average chemical composition are shown to be important parameters in determining the activation properties of those particles around the critical activation diameters for atmospherically-realistic supersaturation values. Closure between predictions and measurements of CCN number at several supersaturations is attempted by modeling a number of aerosol chemical composition and mixing state cases of increasing complexity. It is shown that a realistic treatment of the state of mixing of the urban aerosol distribution is critical in order to eliminate model bias. Fresh emissions such as elemental carbon and small organic particles must be treated as non-activating and explicitly accounted for in the model. The relative number concentration of these particles compared to inorganics and oxygenated organic compounds of limited hygroscopicity plays an important role in determining the CCN number. Furthermore, expanding the different composition/mixing state cases to predictions of cloud droplet number concentration in a cloud parcel model highlights the dependence of cloud optical properties on the state of mixing and hygroscopic properties of the different aerosol modes, but shows that the relative differences between the different cases are reduced compared to those from the CCN model.

scholarly journals New particle formation events observed at the King Sejong Station, Antarctic Peninsula – Part 2: Link with the oceanic biological activities

2018 ◽  
Author(s):  
Eunho Jang ◽  
Ki-Tae Park ◽  
Young Jun Yoon ◽  
Tae-Wook Kim ◽  
Sang-Bum Hong ◽  
...  
Keyword(s):  
Austral Summer ◽  
Particle Formation ◽  
Taxonomic Composition ◽  
Number Concentration ◽  
Weddell Sea ◽  
Marine Biota ◽  
New Particle Formation ◽  
Air Masses ◽  
Bellingshausen Sea ◽  
The Antarctic

Abstract. Marine biota is an important source of atmospheric aerosols in the remote marine atmosphere. Long-term observations (from 2009 to 2016) of the physical properties of atmospheric aerosol particles measured at the Antarctic Peninsula (King Sejong Station; 62.2° S, 58.8° W) and satellite-derived estimates of the biological characteristics were analyzed to identify the link between new particle formation and marine biota. New particle formation events in the Antarctic atmosphere showed distinct seasonal variations, with the highest values occurring during austral summer (December, January and February). Interestingly, new particle formation events were more frequent in the air masses that originated from the Bellingshausen Sea than in those that originated from the Weddell Sea. The monthly mean number concentration of nanoparticles (2.5–10 nm in diameter) was > 2-fold when the air masses passed over the Bellingshausen Sea than the Weddell Sea, whereas the biomass of phytoplankton in the Weddell Sea was more than ~ 70 % higher than that of the Bellingshausen Sea during the austral summer period. Dimethyl sulfide (DMS) is of marine origin and its oxidative products are known to be one of the major components in the formation of new particles. Both satellite-derived estimates of the biological characteristics (dimethylsulfoniopropionate (DMSP; precursor of DMS) and phytoplankton taxonomic composition) and in situ methanesulfonic acid (MSA; oxidation product of DMS) analysis revealed that DMS(P)-rich phytoplankton were more dominant in the Bellingshausen Sea than in the Weddell Sea. Furthermore, the number concentration of nanoparticles was positively correlated with the biomass of phytoplankton during the period when DMS(P)-rich phytoplankton predominate. These results indicate that oceanic DMS emissions could play a key role in the formation of new particles; moreover, the taxonomic composition of phytoplankton could affect the formation of secondary organic aerosols in the Antarctic Ocean.

The influence of volcano activity on aerosol formation over the Andes

2020 ◽  
Author(s):  
Federico Bianchi ◽  
Diego Aliaga ◽  
Qiaozhi Zha ◽  
Liine Heikkinen ◽  
Marcos Andrade ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Sulphuric Acid ◽  
Negative Ions ◽  
Particle Formation ◽  
Amazon Forest ◽  
Particle Nucleation ◽  
New Particle Formation ◽  
Aerosol Formation ◽  
Air Masses ◽  
Particle Sizer

<p>A significant fraction (>50%) of cloud condensation nuclei (CCN) in the atmosphere arises from new particle formation (Dunne et al., 2016). While particle nucleation has been observed almost everywhere in the atmosphere, the mechanisms governing this process are still poorly understood and subject of on-going research. For example, it is still largely unknown which components participate in new-particle formation. Laboratory experiments and quantum chemical calculations have identified potential candidates that may play a role, including sulphuric acid, ions, ammonia, amines and highly oxygenated organic molecules (Kirkby et al., 2011; Almeida et al., 2013; Bianchi et al., 2016; Bianchi et al., 2019).</p><p>Here we present observations of the formation and growth of newly formed particles measured during intense volcano activities.</p><p>The measurements were conducted at Chacaltaya mountain station (5240 m a.s.l.) in Bolivia. The station is located on top of the Cordillera Real. It has air masses coming from the Amazon forest, La Paz and the Bolivian altiplano.</p><p>With the Chemical Ionization Atmospheric Pressure interface Time-Of-Light mass spectrometers (CI-APi-TOF) we measured H<sub>2</sub>SO<sub>4</sub>, the APi-TOF retrieved the chemical composition of positive and negative ions. Ion and particle size distributions were measured with the NAIS (Neutral cluster and Air Ion Spectrometer) and the SMPS (Scanning Mobility Particle Sizer), respectively. The PSM (Particle Sizer Magnifier) measured particles with a cut off that varied from 1-4 nm. Finally, with the ACSM (Aerosol Chemical Speciation Monitor) and the FIGAERO (Filter Inlet for Gases and AEROsols) we retrieved the aerosol chemical composition. Besides this set of instruments, other parameters were measured at the Chacaltaya GAW station.</p><p>During the intensive measurement campaign, air masses coming directly from volcano eruptions were detected by all our instruments. We were therefore able to determine the gas and particle chemical composition of the air mass. In addition to that, we observed several NPF events triggered by air masses coming from volcanic emissions. With this set of instruments, we were able to retrieve the chemical composition of the vapours leading to the formation of new particles. It was found that all the nucleation event observed during the volcano activity were triggered by sulphuric acid and ammonia. In the presentation we will show more details on the chemical and physical mechanism behind this process.</p><p> </p><p>Almeida, J., et al., (2013) Nature 502, 359-363.</p><p>Bianchi, F., et al., (2016) Science 6289, 1109-1112.</p><p>Bianchi, F., et al., (2019) Chemical Review 119, 3472−3509</p><p>Dunne et al., (2016) Science 354, 1119-1124.</p><p>Kirkby, J., et al., (2011) Nature 476, (7361), 429-433.</p>

scholarly journals Secondary new particle formation in Northern Finland Pallas site between the years 2000 and 2010

2011 ◽  
Vol 11 (24) ◽  
pp. 12959-12972 ◽  
Author(s):  
E. Asmi ◽  
N. Kivekäs ◽  
V.-M. Kerminen ◽  
M. Komppula ◽  
A.-P. Hyvärinen ◽  
...  
Keyword(s):  
Growth Rates ◽  
Cloud Condensation Nuclei ◽  
Cloud Droplet ◽  
Detailed Examination ◽  
Particle Formation ◽  
New Particle Formation ◽  
Air Masses ◽  
Event Frequency ◽  
Marine Air

Abstract. Secondary new particle formation affects atmospheric aerosol and cloud droplet numbers and thereby, the aerosol effects on climate. In this paper, the frequency of nucleation events and the associated particle formation and growth rates, along with their seasonal variation, was analysed based on over ten years of aerosol measurements conducted at the Pallas GAW station in northern Finland. The long-term measurements also allowed a detailed examination of factors possibly favouring or suppressing particle formation. Effects of meteorological parameters and air mass properties as well as vapour sources and sinks for particle formation frequency and event parameters were inspected. In addition, the potential of secondary particle formation to increase the concentration of cloud condensation nuclei (CCN) sized particles was examined. Findings from these long-term measurements confirmed previous observations: event frequency peaked in spring and the highest growth rates were observed in summer, affiliated with increased biogenic activity. Events were almost exclusively observed in marine air masses on sunny cloud-free days. A low vapour sink by the background particle population as well as an elevated sulphuric acid concentration were found to favour particle formation. These were also conditions taking place most likely in marine air masses. Inter-annual trend showed a minimum in event frequency in 2003, when also the smallest annual median of growth rate was observed. This gives further evidence of the importance and sensitivity of particle formation for the condensing vapour concentrations at Pallas site. The particle formation was observed to increase CCN80 (>80 nm particle number) concentrations especially in summer and autumn seasons when the growth rates were the highest. When the growing mode exceeded the selected 80 nm limit, on average in those cases, 211 ± 114% increase of CCN80 concentrations was observed.

scholarly journals Sub-micron atmospheric aerosols in the surroundings of Marseille and Athens: physical characterization and new particle formation

2006 ◽  
Vol 6 (5) ◽  
pp. 8605-8647 ◽  
Author(s):  
T. Petäjä ◽  
V.-M. Kerminen ◽  
M. Dal Maso ◽  
H. Junninen ◽  
I. K. Koponen ◽  
...  
Keyword(s):  
Formation Rate ◽  
Particle Formation ◽  
Number Concentration ◽  
Water Soluble ◽  
Aerosol Size Distribution ◽  
New Particle Formation ◽  
Differential Mobility ◽  
Nucleation Mode ◽  
Hygroscopic Properties ◽  
Soluble Material

Abstract. The properties of atmospheric aerosol particles in Marseille and Athens were investigated. The studies were performed in Marseille, France during July 2002 and in Athens Greece during June 2003. The aerosol size distribution and the formation and growth rates of newly formed particles were characterized using Differential Mobility Particle Sizers. Hygroscopic properties were observed using a Hygroscopic Tandem Differential Mobility Analyzer setup. During both campaigns, the observations were performed at suburban, almost rural sites, and the sites can be considered to show general regional background behavior depending on the wind direction. At both sites there were clear pattern for both aerosol number concentration and hygroscopic properties. Nucleation mode number concentration increased during the morning hours indicating new particle formation, which was observed during more than 30% of the days. The observed formation rate was typically more than 1 cm−3 s−1, and the growth rate was between 1.2–9.9 nm h−1. Based on hygroscopicity measurements in Athens, the nucleation mode size increase was due to condensation of both water insoluble and water soluble material. However, during a period of less anthropogenic influence, the growth was to a larger extent due to water insoluble components. When urban pollution was more pronounced, growth due to condensation of water soluble material dominated.

scholarly journals New particle formation at urban and high-altitude remote sites in the south-eastern Iberian Peninsula

2020 ◽  
Author(s):  
Juan Andrés Casquero-Vera ◽  
Hassan Lyamani ◽  
Lubna Dada ◽  
Simo Hakala ◽  
Pauli Paasonen ◽  
...  
Keyword(s):  
High Altitude ◽  
Atmospheric Aerosols ◽  
Global Climate ◽  
Cloud Condensation Nuclei ◽  
Particle Formation ◽  
Aerosol Size Distribution ◽  
Urban Site ◽  
Special Importance ◽  
New Particle Formation ◽  
Remote Sites

Abstract. A substantial fraction of the atmospheric aerosols originates from secondary new particle formation (NPF), where atmospheric vapours are transformed into particles that subsequently grow to larger sizes, affecting human health and the climate. In this study, we investigate aerosol size distributions at two stations located close to each other (~ 20 km), but at different altitudes: urban (UGR; 680 m a.s.l.) and high-altitude remote (SNS; 2500 m a.s.l.) site, both in the area of Granada, Spain, and part of AGORA observatory (Andalusian Global ObseRvatory of the Atmosphere). The analysis shows a significant contribution of nucleation mode aerosol particles to the total aerosol number concentration at both sites, with a contribution of 47 % and 48 % at SNS and UGR, respectively. Due to the important contribution of NPF events to the total aerosol number concentrations and their high occurrence frequency (> 70 %) during the study period, a detailed analysis of NPF events is done in order to get insight into the possible mechanisms and processes involved in NPF events at these contrastive sites. At SNS, NPF is found to be associated with the transport of gaseous precursors from lower altitudes by orographic buoyant upward flows. However, NPF events at SNS site are always observed from the smallest measured sizes of the aerosol size distribution (4 nm), implying that NPF takes place in or in the vicinity of the high-altitude SNS station rather than transported from lower altitudes. Although NPF events at the mountain site seem to be connected with those occurring at the urban site, growth rates (GR) at SNS are higher than those at UGR site (GR7–25 of 6.9 and 4.5 nm h−1 and GR4–7 of 4.1 and 3.6 nm h−1 at SNS and UGR, respectively). This fact could have a special importance on the production of cloud condensation nuclei (CCN) and therefore on cloud formations which may affect regional/global climate, since larger GR at mountain sites could be translated to larger survival probability of NPF particles to reach CCN sizes, due to shorter time needed for the growth. The analysis of sulfuric acid (H2SO4) shows that the contribution of H2SO4 is able to explain a minimal fraction contribution to the observed GRs at both sites (

scholarly journals Observation of nitrate coatings on atmospheric mineral dust particles

2009 ◽  
Vol 9 (6) ◽  
pp. 1863-1871 ◽  
Author(s):  
W. J. Li ◽  
L. Y. Shao
Keyword(s):  
Mineral Dust ◽  
Cloud Condensation Nuclei ◽  
Northern China ◽  
Heterogeneous Reactions ◽  
Dust Particles ◽  
Sample Collection ◽  
Mineral Particles ◽  
Hygroscopic Properties ◽  
Cooling Effects ◽  
Ccn Activity

Abstract. Nitrate compounds have received much attention because of their ability to alter the hygroscopic properties and cloud condensation nuclei (CCN) activity of mineral dust particles in the atmosphere. However, very little is known about specific characteristics of ambient nitrate-coated mineral particles on an individual particle scale. In this study, sample collection was conducted during brown haze and dust episodes between 24 May and 21 June 2007 in Beijing, northern China. Sizes, morphologies, and compositions of 332 mineral dust particles together with their coatings were analyzed using transmission electron microscopy (TEM) coupled with energy-dispersive X-ray (EDX) microanalyses. Structures of some mineral particles were verified using selected-area electron diffraction (SAED). TEM observation indicates that approximately 90% of the collected mineral particles are covered by visible coatings in haze samples whereas only 5% are coated in the dust sample. 92% of the analyzed mineral particles are covered with Ca-, Mg-, and Na-rich coatings, and 8% are associated with K- and S-rich coatings. The majority of coatings contain Ca, Mg, O, and N with minor amounts of S and Cl, suggesting that they are possibly nitrates mixed with small amounts of sulfates and chlorides. These nitrate coatings are strongly correlated with the presence of alkaline mineral components (e.g., calcite and dolomite). CaSO4 particles with diameters from 10 to 500 nm were also detected in the coatings including Ca(NO3)2 and Mg(NO3)2. Our results indicate that mineral particles in brown haze episodes were involved in atmospheric heterogeneous reactions with two or more acidic gases (e.g., SO2, NO2, HCl, and HNO3). Mineral particles that acquire hygroscopic nitrate coatings tend to be more spherical and larger, enhancing their light scattering and CCN activity, both of which have cooling effects on the climate.

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