scholarly journals New particle formation and sub-10 nm size distribution measurements during the A-LIFE field experiment in Paphos, Cyprus

2020 ◽  
Vol 20 (9) ◽  
pp. 5645-5656 ◽  
Author(s):  
Sophia Brilke ◽  
Nikolaus Fölker ◽  
Thomas Müller ◽  
Konrad Kandler ◽  
Xianda Gong ◽  
...  

Abstract. Atmospheric particle size distributions were measured in Paphos, Cyprus, during the A-LIFE (absorbing aerosol layers in a changing climate: ageing, lifetime and dynamics) field experiment from 3 to 30 April 2017. The newly developed differential mobility analyser train (DMA-train) was deployed for the first time in an atmospheric environment for the direct measurement of the nucleation mode size range between 1.8 and 10 nm diameter. The DMA-train set-up consists of seven size channels, of which five are set to fixed particle mobility diameters and two additional diameters are obtained by alternating voltage settings in one DMA every 10 s. In combination with a conventional mobility particle size spectrometer (MPSS) and an aerodynamic particle sizer (APS) the complete atmospheric aerosol size distribution from 1.8 nm to 10 µm was covered. The focus of the A-LIFE study was to characterize new particle formation (NPF) in the eastern Mediterranean region at a measurement site with strong local pollution sources. The nearby Paphos airport was found to be a large emission source for nucleation mode particles, and we analysed the size distribution of the airport emission plumes at approximately 500 m from the main runway. The analysis yielded nine NPF events in 27 measurement days from the combined analysis of the DMA-train, MPSS and trace gas monitors. Growth rate calculations were performed, and a size dependency of the initial growth rate (<10 nm) was observed for one event case. Fast changes of the sub-10 nm size distribution on a timescale of a few minutes were captured by the DMA-train measurement during early particle growth and are discussed in a second event case. In two cases, particle formation and growth were detected in the nucleation mode size range which did not exceed the 10 nm threshold. This finding implies that NPF likely occurs more frequently than estimated from studies where the lower nanometre size regime is not covered by the size distribution measurements.

2019 ◽  
Author(s):  
Sophia Brilke ◽  
Nikolaus Fölker ◽  
Thomas Müller ◽  
Konrad Kandler ◽  
Xianda Gong ◽  
...  

Abstract. Atmospheric particle size distributions were measured in Paphos, Cyprus, during the A-LIFE (Absorbing aerosol layers in a changing climate: aging, lifetime and dynamics) field experiment from April 3–30, 2017. The newly developed DMA-train is deployed for the first time in an atmospheric environment for the direct measurement of the nucleation mode size range between 1.8–10 nm diameter. The DMA-train setup consists of seven size channels, of which five are set to fixed particle mobility diameters and two additional diameters are obtained by alternating voltage settings in one DMA every 10 s. In combination with a conventional Mobility Particle Size Spectrometer (MPSS) and an Aerodynamic Particle Sizer (APS) the complete atmospheric aerosol size distribution from 1.8 nm–10 µm is covered. The focus of the A-LIFE study is to characterize new particle formation (NPF) in the Eastern Mediterranean region at a measurement site with strong local pollution sources. The nearby Paphos airport was found to be a large emission source for nucleation mode particles and we analysed the size distribution of the airport emission plumes at approximately 500 m from the main runway. The analysis yielded 9 NPF events in 27 measurement days from the combined analysis of the DMA-train, MPSS and trace gas monitors. Growth rate calculations were performed and a size-dependency of the initial growth rate (


2012 ◽  
Vol 12 (20) ◽  
pp. 9923-9939 ◽  
Author(s):  
H. Guo ◽  
D. W. Wang ◽  
K. Cheung ◽  
Z. H. Ling ◽  
C. K. Chan ◽  
...  

Abstract. In order to investigate the formation and growth processes of nucleation mode particles, and to quantify the particle number (PN) concentration and size distributions in Hong Kong, an intensive field measurement was conducted from 25 October to 29 November in 2010 near the mountain summit of Tai Mo Shan, a suburban site approximately the geographical centre of the New Territories in Hong Kong. Based on observations of the particle size distribution, new particle formation (NPF) events were found on 12 out of 35 days with the estimated formation rate J5.5 from 0.97 to 10.2 cm−3 s−1, and the average growth rates from 1.5 to 8.4 nm h−1. The events usually began at 10:00–11:00 LT characterized by the occurrence of a nucleation mode with a peak diameter of 6–10 nm. Solar radiation, wind speed, sulfur dioxide (SO2) and ozone (O3) concentrations were on average higher, whereas temperature, relative humidity and daytime nitrogen dioxide (NO2) concentration were lower on NPF days than on non-NPF days. Back trajectory analysis suggested that in majority of the NPF event days, the air masses originated from the northwest to northeast directions. The concentrations of gaseous sulfuric acid (SA) showed good power-law relationship with formation rates, with exponents ranging from 1 to 2. The result suggests that the cluster activation theory and kinetic nucleation could potentially explain the observed NPF events in this mountainous atmosphere of Hong Kong. Meanwhile, in these NPF events, the contribution of sulfuric acid vapor to particle growth rate (GR5.5–25) ranged from 9.2 to 52.5% with an average of 26%. Measurement-based calculated oxidation rates of monoterpenes (i.e. α-pinene, β-pinene, myrcene and limonene) by O3 positively correlated with the GR5.5–25 (R = 0.80, p < 0.05). The observed associations of the estimated formation rate J5.5 and the growth rate GR5.5–25 with gaseous sulfuric acid and volatile organic compounds (VOCs) suggested the critical roles of sulfuric acid and biogenic VOCs (e.g. α-pinene and β-pinene) in these NPF events.


2021 ◽  
Vol 9 ◽  
Author(s):  
Sandhya Jose ◽  
Amit Kumar Mishra ◽  
Neelesh K. Lodhi ◽  
Sudhir Kumar Sharma ◽  
Sachchidanand Singh

Accurate information about aerosol particle size distribution and its variation under different meteorological conditions are essential for reducing uncertainties related to aerosol-cloud-climate interaction processes. New particle formation (NPF) and the coagulation significantly affect the aerosol size distribution. Here we study the monthly and seasonal variability of aerosol particle size distribution at Delhi from December 2011 to January 2013. Analysis of aerosol particle size distribution using WRAS-GRIMM reveals that aerosol particle number concentration is highest during the post monsoon season owing to the effect of transported crop residue and biomass burning aerosols. Diurnal variations in number concentration show a bimodal pattern with two Aitken mode peaks in all the seasons. Monthly volume size distribution also shows bi-modal distribution with distinct coarse and fine modes. NPF events are observed less frequently in Delhi. Out of 222 days of WRAS data, only 17 NPF events have been observed, with higher NPF frequency during summer season. Growth rate of the nucleation mode of NPF events vary in the range 1.88–21.66 nm/h with a mean value of ∼8.45 ± 5.73 nm/h. It is found that during NPF events the Aitken and nucleation mode particles contribute more to the number concentration. Simultaneous measurement of UV flux and particulate matter (PM10 and PM2.5) have also been done along with particle number size distribution measurement to understand the possible mechanisms for NPF events over the study location.


2012 ◽  
Vol 12 (17) ◽  
pp. 8021-8036 ◽  
Author(s):  
P. Crippa ◽  
T. Petäjä ◽  
H. Korhonen ◽  
G. S. El Afandi ◽  
S. C. Pryor

Abstract. New particle formation has been observed at a number of ground-based measurement sites. Prior research has provided evidence that this new particle formation, while observed in the near-surface layer, is actually occurring in atmospheric layers above the surface and appears to be focused in or close to the residual layer formed by the nocturnal inversion. Here, we present both observations and modeling for southern Indiana which support this postulate. Based on simulations with a detailed aerosol dynamics model and the Weather Research and Forecasting model, along with data from ground-based remote sensing instruments and detailed gas and particle phase measurements, we show evidence that (i) the maximum rate change of ultrafine particle concentrations as observed close to the surface is always preceded by breakdown of the nocturnal inversion and enhancement of vertical mixing and (ii) simulated particle size distributions exhibit greatest accord with surface observations during and subsequent to nucleation only when initialized with a particle size distribution representative of clear atmospheric conditions, rather than the in situ (ground-level) particle size distribution.


2014 ◽  
Vol 14 (10) ◽  
pp. 15149-15189 ◽  
Author(s):  
J. F. Peng ◽  
M. Hu ◽  
Z. B. Wang ◽  
X. F. Huang ◽  
P. Kumar ◽  
...  

Abstract. Understanding the particle number size distributions in diversified atmospheric environments is important in order to design mitigation strategies related to submicron particles and their effect on regional air quality, haze and human health. In this study, we conducted 15 different field measurement campaigns, each one-month long, between 2007 and 2011 at 13 individual sites in China. These were 5 urban sites, 4 regional sites, 3 coastal/background sites and one ship cruise measurement along eastern coastline of China. Size resolved particles were measured in the 15–600 nm size range. The median particle number concentrations (PNC) were found to vary in the range of 1.1–2.2 × 104 cm−3 at urban sites, 0.8–1.5 × 104 cm−3 at regional sites, 0.4–0.6 × 104 cm−3 at coastal/background sites, and 0.5 × 104 cm−3 during cruise measurements. Peak diameters at each of these sites varied greatly from 24 nm to 115 nm. Particles in the 15–25 nm (nucleation mode), 25–100 nm (Aitken mode) and 100–600 nm (accumulation mode) range showed different characteristics at each of the studied sites, indicating the features of primary emissions and secondary formation in these diversified atmospheric environments. Diurnal variations show a build-up of accumulation mode particles belt at regional sites, suggesting the contribution of regional secondary aerosol pollution. Frequencies of new particle formation (NPF) events were much higher at urban and regional sites than at coastal sites and cruise measurement. The average growth rates (GRs) of nucleation mode particles were 8.0–10.9 nm h−1 at urban sites, 7.4–13.6 nm h−1 at regional sites and 2.8–7.5 nm h−1 at both coastal and cruise measurement sites. The high gaseous precursors and strong oxidation at urban and regional sites not only favored the formation of particles, but also accelerated the growth rate of the nucleation mode particles. No significant difference in condensation sink (CS) during NPF days were observed among different site types, suggesting that the NPF events in background area were more influenced by the pollutant transport. In addition, average contributions of NPF events to potential cloud condensation nuclei (CCN) at 0.2% super-saturation in the afternoon of all sampling days were calculated as 11% and 6% at urban sites and regional sites, respectively. On the other hand, NPF events at coastal and cruise measurement sites had little impact on potential production of CCN. This study provides a large dataset of aerosol size distribution in diversified atmosphere of China, improving our general understanding of emission, secondary formation, new particles formation and corresponding CCN activity of submicron aerosols in Chinese environments.


2021 ◽  
Author(s):  
Anastasiia Demakova ◽  
Olga Garmash ◽  
Ekaterina Ezhova ◽  
Mikhail Arshinov ◽  
Denis Davydov ◽  
...  

&lt;p&gt;New Particle Formation (NPF) is a process in which a large number of particles is formed in the atmosphere via gas-to-particle conversion. Previous research shows the important role of formation of new particles for atmosphere, clouds and climate (Kerminen, V.-M. et al. 2018).&lt;/p&gt;&lt;p&gt;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160; There exist measurements from different parts of the world which show that NPF is happening worldwide (Kerminen, V.-M. et al. 2018). Measurements at SMEAR II station in Hyyti&amp;#228;l&amp;#228;, Finland (Hari P. and Kulmala M., 2005), show that NPF is a common process in Finland&amp;#8217;s boreal forests. However, measurements at Zotto station in Siberia, Russia, show that NPF events are very rare in that area (Wiedensohler A. et al., 2018). Measurements in Siberian boreal forests are sparse. We have conducted new measurements at Fonovaya station near Tomsk (Siberia, Russia) using Neutral cluster Air Ion Spectrometer (NAIS), Particle Size Magnifier (PSM), Differential Mobility Particle Sizer (DMPS) and the Atmospheric Pressure interface Time-Of-Flight mass spectrometer (APi-TOF). Those instruments measure aerosol particle number size distribution (NAIS, DMPS), ion number size distribution (NAIS), size distribution of small particles (PSM) and chemical composition of aerosol particles (APi-TOF). The novelty of this work is that such complex measurements have not been done in Siberia before.&lt;/p&gt;&lt;p&gt;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160; Here we report the first results of our research on NPF phenomenon in Siberian boreal forest. We present detailed statistics of NPF events, as well as formation rates (J) and growth rates (GR) of aerosol particles. The results from Fonovaya station are compared with those from SMEAR II station and from SMEAR Estonia station in J&amp;#228;rvselja, Estonia.&lt;/p&gt;&lt;p&gt;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160; &amp;#160;&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;Literature&lt;/p&gt;&lt;ul&gt;&lt;li&gt;[1] Kerminen V.-M. et al. &amp;#8220;Atmospheric new particle formation and growth: review of field observations&amp;#8221;. In: Environmental Research Letters 10 (2018), p. 103003.&lt;/li&gt; &lt;li&gt;[2] Wiedensohler A. et al. &amp;#8220;Infrequent new particle formation over the remote boreal forest of Siberia&amp;#8221;. In: Atmospheric Environment 200 (2019), pp. 167&amp;#8211;169.&lt;/li&gt; &lt;li&gt;[3] Dada L. et al. &amp;#8220;Long-term analysis of clear-sky new particle formation events and nonevents in Hyyti&amp;#228;l&amp;#228;&amp;#8221;. In: Atmospheric Chemistry and Physics 10 (2017), pp. 6227&amp;#8211;6241.&lt;/li&gt; &lt;/ul&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;


2010 ◽  
Vol 136 (649) ◽  
pp. 944-961 ◽  
Author(s):  
Justin R. Peter ◽  
Steven T. Siems ◽  
Jørgen B. Jensen ◽  
John L. Gras ◽  
Yutaka Ishizaka ◽  
...  

2013 ◽  
Vol 13 (17) ◽  
pp. 8935-8946 ◽  
Author(s):  
H. C. Cheung ◽  
C. C.-K. Chou ◽  
W.-R. Huang ◽  
C.-Y. Tsai

Abstract. An intensive aerosol characterization experiment was performed at the Taipei Aerosol and Radiation Observatory (TARO, 25.02° N, 121.53° E) in the urban area of Taipei, Taiwan, during July 2012. Number concentration and size distribution of aerosol particles were measured continuously, which were accompanied by concurrent measurements of mass concentration of submicron particles, PM1 (d ≤ 1 μm), and photolysis rate of ozone, J(O1D). The averaged number concentrations of total (Ntotal), accumulation mode (Nacu), Aitken mode (NAitken), and nucleation mode (Nnuc) particles were 13.9 × 103 cm−3, 1.2 × 103 cm−3, 6.1 × 103 cm−3, and 6.6 × 103 cm−3, respectively. Accordingly, the ultrafine particles (UFPs, d ≤ 100 nm) accounted for 91% of the total number concentration of particles measured in this study (10 ≤ d ≤ 429 nm), indicating the importance of UFPs to the air quality and radiation budget in Taipei and its surrounding areas. An averaged Nnuc / NOx ratio of 192.4 cm−3 ppbv−1 was derived from nighttime measurements, which was suggested to be the characteristic of vehicle emissions that contributed to the "urban background" of nucleation mode particles throughout a day. On the contrary, it was found that the number concentration of nucleation mode particles was independent of NOx and could be elevated up to 10 times of the "urban background" levels during daytime, suggesting a substantial amount of nucleation mode particles produced from photochemical processes. Averages (± 1σ) of the diameter growth rate (GR) and formation rate of nucleation mode particles, J10, were 11.9 ± 10.6 nm h−1 and 6.9 ± 3.0 cm−3 s−1, respectively. Consistency in the time series of the nucleation mode particle concentration and the proxy of H2SO4 production, UVB · SO2/CS, for new particle formation (NPF) events suggested that photooxidation of SO2 was likely one of the major mechanisms for the formation of new particles in our study area. Moreover, it was revealed that the particle growth rate correlated exponentially with the photolysis of ozone, implying that the condensable vapors were produced mostly from photooxidation reactions. In addition, this study also revealed that Nnuc exhibited a quadratic relationship with J10. The quadratic relationship was inferred as a result of aerosol dynamics and featured NPF processes in urban areas.


2007 ◽  
Vol 7 (3) ◽  
pp. 677-684 ◽  
Author(s):  
M. Ehn ◽  
T. Petäjä ◽  
W. Birmili ◽  
H. Junninen ◽  
P. Aalto ◽  
...  

Abstract. The volatility of sub-micrometer atmospheric aerosol particles was studied in a rural background environment in Finland using a combination of a heating tube and a scanning mobility particle sizer. The analysis focused on nanoparticles formed through nucleation which were subsequently observed during their growth in the diameter range between 5 and 60 nm. During the 6 days of new particle formation shown in detail, the concentrations of newly formed particles increased up to 10 000 cm−3. The number of nucleation mode particles measured after volatilization in the heating tube at 280°C was up to 90% of the total number under ambient conditions. Taking into account the absolute accuracy of the size distribution measurements, all ambient particles found in the rural atmosphere could have a non-volatile core after volatilization at 280°C. As the regional new particle formation events developed over time as a result of further vapor condensation, the newly formed particles grew at an average growth rate of 2.4±0.3 nm h−1. Importantly, the non-volatile cores of nucleation mode particles were also observed to grow over time, however, at a lower average growth rate of 0.6±0.3 nm h−1. One implication of the volatility analysis is that the newly formed particles, which have reached ambient diameters of 15 nm, are unlikely to consist of sulfuric acid, ammonium sulfate, and water alone. A relatively constant ratio between the growth rate of the ambient particles as well as their non-volatile cores indicates that non-volatile matter is formed only gradually in the growing particles. The non-volatile fraction of the particles showed some correlation with the ambient temperature. The composition and formation mechanism of this non-volatile material in nucleation mode particles are, to date, not known.


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