scholarly journals New particle formation in Beijing, China: Statistical analysis of a 1-year data set

2007 ◽  
Vol 112 (D9) ◽  
Author(s):  
Zhijun Wu ◽  
Min Hu ◽  
Shang Liu ◽  
Birgit Wehner ◽  
Stefan Bauer ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Particle Formation ◽  
New Particle Formation ◽  
Data Set ◽  
Beijing China

scholarly journals CCN production by new particle formation in the free troposphere

2017 ◽  
Vol 17 (2) ◽  
pp. 1529-1541 ◽  
Author(s):  
Clémence Rose ◽  
Karine Sellegri ◽  
Isabel Moreno ◽  
Fernando Velarde ◽  
Michel Ramonet ◽  
...  
Keyword(s):  
Particle Number ◽  
Particle Growth ◽  
Particle Formation ◽  
Number Concentration ◽  
Particle Number Concentration ◽  
Free Troposphere ◽  
New Particle Formation ◽  
Data Set ◽  
Radiative Processes ◽  
The Impact

Abstract. Global models predict that new particle formation (NPF) is, in some environments, responsible for a substantial fraction of the total atmospheric particle number concentration and subsequently contributes significantly to cloud condensation nuclei (CCN) concentrations. NPF events were frequently observed at the highest atmospheric observatory in the world, on Chacaltaya (5240 m a.s.l.), Bolivia. The present study focuses on the impact of NPF on CCN population. Neutral cluster and Air Ion Spectrometer and mobility particle size spectrometer measurements were simultaneously used to follow the growth of particles from cluster sizes down to ∼ 2 nm up to CCN threshold sizes set to 50, 80 and 100 nm. Using measurements performed between 1 January and 31 December 2012, we found that 61 % of the 94 analysed events showed a clear particle growth and significant enhancement of the CCN-relevant particle number concentration. We evaluated the contribution of NPF, relative to the transport and growth of pre-existing particles, to CCN size. The averaged production of 50 nm particles during those events was 5072, and 1481 cm−3 for 100 nm particles, with a larger contribution of NPF compared to transport, especially during the wet season. The data set was further segregated into boundary layer (BL) and free troposphere (FT) conditions at the site. The NPF frequency of occurrence was higher in the BL (48 %) compared to the FT (39 %). Particle condensational growth was more frequently observed for events initiated in the FT, but on average faster for those initiated in the BL, when the amount of condensable species was most probably larger. As a result, the potential to form new CCN was higher for events initiated in the BL (67 % against 53 % in the FT). In contrast, higher CCN number concentration increases were found when the NPF process initially occurred in the FT, under less polluted conditions. This work highlights the competition between particle growth and the removal of freshly nucleated particles by coagulation processes. The results support model predictions which suggest that NPF is an effective source of CCN in some environments, and thus may influence regional climate through cloud-related radiative processes.

scholarly journals Climatology of new particle formation at Izaña mountain GAW observatory in the subtropical North Atlantic

2014 ◽  
Vol 14 (8) ◽  
pp. 3865-3881 ◽  
Author(s):  
M. I. García ◽  
S. Rodríguez ◽  
Y. González ◽  
R. D. García
Keyword(s):  
Sulfuric Acid ◽  
North Atlantic ◽  
Growth Rates ◽  
Particle Growth ◽  
Particle Formation ◽  
Dust Particles ◽  
New Particle Formation ◽  
Data Set ◽  
Mean Values ◽  
Condensation Sink

Abstract. A climatology of new particle formation (NPF) events at high altitude in the subtropical North Atlantic is presented. A 4-year data set (June 2008–June 2012), which includes number size distributions (10–600 nm), reactive gases (SO2, NOx, and O3), several components of solar radiation and meteorological parameters, measured at Izaña Global Atmosphere Watch (GAW) observatory (2373 m above sea level; Tenerife, Canary Islands) was analysed. NPF is associated with the transport of gaseous precursors from the boundary layer by orographic buoyant upward flows that perturb the low free troposphere during daytime. On average, 30% of the days contained an NPF event. Mean values of the formation and growth rates during the study period were 0.46 cm−3 s−1 and 0.42 nm h−1, correspondingly. There is a clearly marked NPF season (May–August), when these events account for 50–60% of the days per month. Monthly mean values of the formation and growth rates exhibit higher values in this season, 0.49–0.92 cm−3 s−1 and 0.48–0.58 nm h−1, respectively. During NPF events, SO2, UV radiation and upslope winds showed higher values than during non-events. The overall data set indicates that SO2 plays a key role as precursor, although other species seem to contribute during some periods. Condensation of sulfuric acid vapour accounts for most of the measured particle growth during most of the year (~70%), except for some periods. In May, the highest mean growth rates (~0.6 nm h−1) and the lowest contribution of sulfuric acid (~13%) were measured, suggesting a significant involvement of other condensing vapours. The SO2 availability seems also to be the most influencing parameter in the year-to-year variability in the frequency of NPF events. The condensation sink showed similar features to other mountain sites, showing high values during NPF events. Summertime observations, when Izaña is within the Saharan Air Layer, suggest that dust particles may play a significant role acting as coagulation sink of freshly formed nucleation particles. The contribution of dust particles to the condensation sink of sulfuric acid vapours seems to be modest (~8% as average). Finally, we identified a set of NPF events in which two nucleation modes, which may evolve at different rates, occur simultaneously and for which further investigations are necessary.

scholarly journals An improved criterion for new particle formation in diverse atmospheric environments

2010 ◽  
Vol 10 (17) ◽  
pp. 8469-8480 ◽  
Author(s):  
C. Kuang ◽  
I. Riipinen ◽  
S.-L. Sihto ◽  
M. Kulmala ◽  
A. V. McCormick ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Growth Rates ◽  
Particle Growth ◽  
Particle Formation ◽  
Balance Model ◽  
New Particle Formation ◽  
Data Set ◽  
Surface Areas ◽  
Recent Developments ◽  
Diverse Data

Abstract. A dimensionless theory for new particle formation (NPF) was developed, using an aerosol population balance model incorporating recent developments in nucleation rates and measured particle growth rates. Based on this theoretical analysis, it was shown that a dimensionless parameter LΓ, characterizing the ratio of the particle scavenging loss rate to the particle growth rate, exclusively determined whether or not NPF would occur on a particular day. This parameter determines the probability that a nucleated particle will grow to a detectable size before being lost by coagulation with the pre-existing aerosol. Cluster-cluster coagulation was shown to contribute negligibly to this survival probability under conditions pertinent to the atmosphere. Data acquired during intensive measurement campaigns in Tecamac (MILAGRO), Atlanta (ANARChE), Boulder, and Hyytiälä (QUEST II, QUEST IV, and EUCAARI) were used to test the validity of LΓ as an NPF criterion. Measurements included aerosol size distributions down to 3 nm and gas-phase sulfuric acid concentrations. The model was applied to seventy-seven NPF events and nineteen non-events (characterized by growth of pre-existing aerosol without NPF) measured in diverse environments with broad ranges in sulfuric acid concentrations, ultrafine number concentrations, aerosol surface areas, and particle growth rates (nearly two orders of magnitude). Across this diverse data set, a nominal value of LΓ=0.7 was found to determine the boundary for the occurrence of NPF, with NPF occurring when LΓ<0.7 and being suppressed when LΓ>0.7. Moreover, nearly 45% of measured LΓ values associated with NPF fell in the relatively narrow range of 0.1

scholarly journals New particle formation and ultrafine charged aerosol climatology at a high altitude site in the Alps (Jungfraujoch, 3580 m a.s.l., Switzerland)

2010 ◽  
Vol 10 (19) ◽  
pp. 9333-9349 ◽  
Author(s):  
J. Boulon ◽  
K. Sellegri ◽  
H. Venzac ◽  
D. Picard ◽  
E. Weingartner ◽  
...  
Keyword(s):  
High Altitude ◽  
Particle Formation ◽  
Ion Source ◽  
Swiss Alps ◽  
Aerosol Size Distribution ◽  
New Particle Formation ◽  
Data Set ◽  
Air Mass ◽  
Air Masses ◽  
Charged Aerosol

Abstract. We investigate the formation and growth of charged aerosols clusters at Jungfraujoch, in the Swiss Alps (3580 m a.s.l.), the highest altitude site of the European EUCAARI project intensive campaign. Charged particles and clusters (0.5–1.8 nm) were measured from April 2008 to April 2009 and allowed the detection of nucleation events in this very specific environment (presence of free tropospheric air and clouds). We found that the naturally charged aerosol concentrations, which are dominated by the cluster size class, shows a strong diurnal pattern likely linked to valley breezes transporting surface layer ion precursors, presumably radon. Cosmic rays were found not to be the major ion source at the measurement site. However, at night, when air masses are more representative of free tropospheric conditions, we found that the cluster concentrations are still high. The charged aerosol size distribution and concentration are strongly influenced by the presence of clouds at the station. Clouds should be taken into account when deriving high altitude nucleation statistics. New particle formation occurs on average 17.5% of the measurement period and shows a weak seasonality with a minimum of frequency during winter, but this seasonality is enhanced when the data set is screened for periods when the atmospheric station is out of clouds. The role of ions in the nucleation process was investigated and we found that the ion-mediated nucleation explains 22.3% of the particle formation. The NPF events frequency is correlated with UV radiation but not with calculated H2SO4 concentrations, suggesting that other compounds such as organic vapors are involved in the nucleation and subsequently growth process. In fact, NPF events frequency also surprisingly increases with the condensational sink (CS), suggesting that at Jungfraujoch, the presence of condensing vapours probably coupled with high CS are driving the occurrence of NPF events. A strong link to the air mass path was also pointed out and events were observed to be frequently occurring in Eastern European air masses, which present the highest condensational sink. In these air masses, pre-existing cluster concentrations are more than three time larger than in other air masses during event days, and no new clusters formation is observed, contrarily to what is happening in other air mass types.

Particle growth with photochemical age from new particle formation to haze in the winter of Beijing, China

2021 ◽  
Vol 753 ◽  
pp. 142207
Author(s):  
Biwu Chu ◽  
Lubna Dada ◽  
Yongchun Liu ◽  
Lei Yao ◽  
Yonghong Wang ◽  
...  
Keyword(s):  
Particle Growth ◽  
Particle Formation ◽  
New Particle Formation ◽  
Beijing China ◽  
Photochemical Age

scholarly journals An improved criterion for new particle formation in diverse atmospheric environments

2010 ◽  
Vol 10 (1) ◽  
pp. 491-521 ◽  
Author(s):  
C. Kuang ◽  
I. Riipinen ◽  
S.-L. Sihto ◽  
M. Kulmala ◽  
A. V. McCormick ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Growth Rates ◽  
Particle Growth ◽  
Particle Formation ◽  
Balance Model ◽  
New Particle Formation ◽  
Data Set ◽  
Surface Areas ◽  
Recent Developments ◽  
Diverse Data

Abstract. A dimensionless theory for new particle formation (NPF) was developed, using an aerosol population balance model incorporating recent developments in nucleation rates and measured particle growth rates. Based on this theoretical analysis, it was shown that a dimensionless parameter LΓ, characterizing the ratio of the particle scavenging loss rate to the particle growth rate, exclusively determined whether or not NPF would occur on a particular day. This parameter determines the probability that a nucleated particle will grow to a detectable size before being lost by coagulation with the pre-existing aerosol. Cluster-cluster coagulation was shown to contribute negligibly to this survival probability under conditions pertinent to the atmosphere. Data acquired during intensive measurement campaigns in Tecamac (MILAGRO), Atlanta (ANARChE), Boulder, and Hyytiälä (QUEST II, QUEST IV, and EUCAARI) were used to test the validity of LΓ as an NPF criterion. Measurements included aerosol size distributions down to 3 nm and gas-phase sulfuric acid concentrations. The model was applied to seventy-seven NPF events and nineteen non-events (characterized by growth of pre-existing aerosol without NPF) measured in diverse environments with broad ranges in sulfuric acid concentrations, ultrafine number concentrations, aerosol surface areas, and particle growth rates (nearly two orders of magnitude). Across this diverse data set, a nominal value of LΓ=0.7 was found to determine the boundary for the occurrence of NPF, with NPF occurring when LΓ<0.7 and being suppressed when LΓ> 0.7. Moreover, nearly 45% of measured LΓ values associated with NPF fell in the relatively narrow range of 0.1<LΓ<0.3.

scholarly journals Atmospheric nanoparticle observations in the low free troposphere during upward orographic flows at Izaña Mountain Observatory

2009 ◽  
Vol 9 (17) ◽  
pp. 6319-6335 ◽  
Author(s):  
S. Rodríguez ◽  
Y. González ◽  
E. Cuevas ◽  
R. Ramos ◽  
P. M. Romero ◽  
...  
Keyword(s):  
Surface Area ◽  
Particle Formation ◽  
Saharan Dust ◽  
Dust Particles ◽  
Formation Mechanisms ◽  
High Mountain ◽  
Type I ◽  
Free Troposphere ◽  
New Particle Formation ◽  
Data Set

Abstract. This study investigates the processes and conditions favouring the formation of nanoparticles (diameter<10 nm) which are frequently observed on high mountains reaching the low free troposphere. This was done through an analysis of a data set collected at Izaña Global Atmospheric Watch Observatory (Canary Islands; 2367 m above sea level). This high mountain supersite is located well above the stratocumulus layer characteristic of the subtropical oceanic tropospheres. At night, when the catabic flow regime is well established, free troposphere aerosols were measured. The development of orographic buoyant upward flows during daylight resulted in an increase of water vapour, SO2 and NOy concentrations. These ascending airflows perturbed the free troposphere and resulted in high concentrations of 3–10 nm particles (N3–10) due to new particle formation. An analysis of the 5-min average time series allowed the identification of two main types of N3–10 event. In Type I events a linear relationship between N3–10 and SO2 was observed (r2 coefficients 0.70–0.95 and a mean slope of 11 cm−3 ppt−1 for 5-min averaged data; SO2 concentrations from tens to hundreds of ppt). These particles seem to be formed during upward transport (probably within or after the outflows of clouds typically located below Izaña). During Type II events, no correlation between SO2 and N3–10 was observed and 3–10 nm particles were formed in-situ at noon and during the afternoon due to the condensation of vapours linked to photochemistry. New particle formation was observed almost every day owing to the favourable conditions associated with the entry of boundary layer air in the low free troposphere, even if SO2 concentrations are rather low at Izaña (tens to hundreds of ppt). The low surface area of pre-existing particles, low temperature and high radiation intensity clearly favoured the formation of nanoparticles. The low surface area of pre-existing particles in the upward flows is furthered by in-cloud particles scavenging in the stratocumulus layer typically located below Izaña. The higher temperature and the presence of coarse Saharan dust particles decrease the efficiency of the new particle formation mechanisms in summer. Thus, the "N3–10 versus SO2" slope (for r2>0.7 cases) was higher in autumn and winter (~15 cm−3 ppt−1 as average) than in summer (2–8 cm−3 ppt−1). These field observations suggest that elevated mounts that reaches the free troposphere may act as source regions for new particles.

scholarly journals Particle hygroscopicity and its link to chemical composition in the urban atmosphere of Beijing, China, during summertime

2016 ◽  
Vol 16 (2) ◽  
pp. 1123-1138 ◽  
Author(s):  
Z. J. Wu ◽  
J. Zheng ◽  
D. J. Shang ◽  
Z. F. Du ◽  
Y. S. Wu ◽  
...  
Keyword(s):  
Particle Size ◽  
Chemical Composition ◽  
Growth Factor ◽  
Mass Concentration ◽  
Particle Formation ◽  
High Time Resolution ◽  
New Particle Formation ◽  
Hygroscopic Growth ◽  
Hygroscopic Properties ◽  
Beijing China

Abstract. Simultaneous measurements of particle number size distribution, particle hygroscopic properties, and size-resolved chemical composition were made during the summer of 2014 in Beijing, China. During the measurement period, the mean hygroscopicity parameters (κs) of 50, 100, 150, 200, and 250 nm particles were respectively 0.16  &amp;pm;  0.07, 0.19  &amp;pm;  0.06, 0.22  &amp;pm;  0.06, 0.26  &amp;pm;  0.07, and 0.28  &amp;pm;  0.10, showing an increasing trend with increasing particle size. Such size dependency of particle hygroscopicity was similar to that of the inorganic mass fraction in PM1. The hydrophilic mode (hygroscopic growth factor, HGF  >  1.2) was more prominent in growth factor probability density distributions and its dominance of hydrophilic mode became more pronounced with increasing particle size. When PM2.5 mass concentration was greater than 50 μg m−3, the fractions of the hydrophilic mode for 150, 250, and 350 nm particles increased towards 1 as PM2.5 mass concentration increased. This indicates that aged particles dominated during severe pollution periods in the atmosphere of Beijing. Particle hygroscopic growth can be well predicted using high-time-resolution size-resolved chemical composition derived from aerosol mass spectrometer (AMS) measurements using the Zdanovskii–Stokes–Robinson (ZSR) mixing rule. The organic hygroscopicity parameter (κorg) showed a positive correlation with the oxygen to carbon ratio. During the new particle formation event associated with strongly active photochemistry, the hygroscopic growth factor or κ of newly formed particles is greater than for particles with the same sizes not during new particle formation (NPF) periods. A quick transformation from external mixture to internal mixture for pre-existing particles (for example, 250 nm particles) was observed. Such transformations may modify the state of the mixture of pre-existing particles and thus modify properties such as the light absorption coefficient and cloud condensation nuclei activation.

scholarly journals New particle formation in the Svalbard region 2006–2015

2016 ◽  
Author(s):  
Jost Heintzenberg ◽  
Peter Tunved ◽  
Martí Gali ◽  
Caroline Leck
Keyword(s):  
Seasonal Cycle ◽  
Particle Formation ◽  
Seasonal Distribution ◽  
Solar Flux ◽  
Biologically Active ◽  
Late Winter ◽  
Particle Nucleation ◽  
New Particle Formation ◽  
Data Set ◽  
Marine Biological

Abstract. Events of new particle formation, (NPF), were analyzed in a ten-year data set of hourly particle size distributions recorded on Mt. Zeppelin, Spitsbergen, Svalbard. Three different types of NPF-events were identified through objective search algorithms. The first and simplest algorithm utilizes short-term increases in particle concentrations below 25 nm, (PCT-events). The second one builds on the growth of the sub-50 nm diameter-median, (DGR-events), and is most closely related to the classical "banana-type" of events. The third and most complex, so-called multiple-size approach to identifying NPF-events builds on a hypothesis suggesting the concurrent production of polymer gel particles at several sizes below about 60 nm, (MEV-events). As a first and general conclusion we can state that NPF-events are a summer phenomenon and not related to Arctic haze, which is a late winter-to-early spring event. NPF-events appear to be somewhat sensitive to the available data on precipitation. The seasonal distribution of solar flux suggests some photochemical control that may affect marine biological processes generating particle precursors and/or atmospheric photochemical processes that generate condensable vapors from precursor gases. Whereas the seasonal distribution of the biogenic methanesulfonate, (MSA), follows that of the solar flux it peaks before the maxima in NPF-occurrence. A host of ancillary data and findings point to varying and rather complex marine biological source processes. The potential source regions for all types of new particle formation appear to be restricted to the marginal ice and open water areas between Northeastern Greenland and Eastern Svalbard. Depending on conditions yet to be clarified new particle formation may become visible as short bursts of particles around 20 nm, (PCT-events), longer events involving condensation growth, (DGR-events), or extended events with elevated concentrations of particles at several sizes below 100 nm, (MEV-events). The seasonal distribution of NPF-events peaks later than that of MSA and, DGR and in particular of MEV-events reach into late summer and early fall with much open, warm, and biologically active waters around Svalbard. Consequently, a simple model to describe the seasonal distribution of the total number of NPF-events can be based on solar flux, and sea surface temperature, representing environmental conditions for marine biological activity, and condensation sink, controlling the balance between new particle nucleation and their condensational growth. Based on the sparse knowledge about the seasonal cycle of gel-forming marine microorganisms and their controlling factors we hypothesize that the seasonal distribution of DGR and more so MEV-events reflect the seasonal cycle of the gel-forming phytoplankton.

scholarly journals Investigation of the connections between atmospheric new particle formation and organics at an urban site of Beijing

2013 ◽  
Vol 13 (2) ◽  
pp. 3419-3450 ◽  
Author(s):  
Z. B. Wang ◽  
M. Hu ◽  
Z. J. Wu ◽  
D. L. Yue ◽  
J. Zheng ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Correlation Coefficients ◽  
Particle Formation ◽  
Nucleation Theory ◽  
Urban Site ◽  
New Particle Formation ◽  
Organic Vapors ◽  
Data Set ◽  
High Background ◽  
Nucleation Mechanisms

Abstract. The role of low-volatility organic vapors in atmospheric new particle formation has been studied based on a data set of 17 nucleation events observed during the CAREBeijing 2008 campaign. The particle formation rates show good correlations with sulfuric acid and organic vapors implying that both play an important role in the atmospheric new particle formation. High correlation coefficients are observed in all investigated nucleation mechanisms. The best fit (R = 0.73, slope = 1.1) between the observed and modelled particle formation rates is achieved with the homogenous nucleation theory of sulfuric acid (both homomolecularly and hetermolecularly) with separate coefficients in J=KSA1[H2SO4]2+KSA2[H2SO4][Org]. The contributions of the sulfuric acid and the organics involving terms have been 43% and 57%, respectively. In addition, the higher particle formation rates are observed on polluted nucleation days, indicating the organic vapors should be involved in the new particle formation process in the polluted urban environment of Beijing with high background aerosol loading.

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