scholarly journals Measurement report: New particle formation characteristics at an urban and a mountain station in northern China

2021 ◽  
Vol 21 (23) ◽  
pp. 17885-17906
Author(s):  
Ying Zhou ◽  
Simo Hakala ◽  
Chao Yan ◽  
Yang Gao ◽  
Xiaohong Yao ◽  
...  
Keyword(s):  
Urban Areas ◽  
Formation Rate ◽  
Northern China ◽  
Particle Formation ◽  
Urban Site ◽  
New Particle Formation ◽  
Large Area ◽  
Air Mass ◽  
Mountain Site ◽  
Favorable Conditions

Abstract. Atmospheric new particle formation (NPF) events have attracted increasing attention for their contribution to the global aerosol number budget and therefore their effects on climate, air quality and human health. NPF events are regarded as a regional phenomenon, occurring over a large area. Most observations of NPF events in Beijing and its vicinity were conducted in populated areas, whereas observations of NPF events on mountaintops with low anthropogenic emissions are still rare in China. The spatial variation of NPF event intensity has not been investigated in detail by incorporating both urban areas and mountain measurements in Beijing. Here, we provide NPF event characteristics in summer 2018 and 2019 at urban Beijing and a comparison of NPF event characteristics – NPF event frequency, formation rate and growth rate – by comparing an urban Beijing site and a background mountain site separated by ∼80 km from 14 June to 14 July 2019, as well as giving insights into the connection between both locations. During parallel measurements at urban Beijing and mountain background areas, although the median condensation sink during the first 2 h of the common NPF events was around 0.01 s−1 at both sites, there were notable differences in formation rates between the two locations (median of 5.42 cm−3 s−1 at the urban site and 1.13 cm−3 s−1 at the mountain site during the first 2 h of common NPF events). In addition, the growth rates in the 7–15 nm range for common NPF events at the urban site (median of 7.6 nm h−1) were slightly higher than those at the mountain site (median of 6.5 nm h−1). To understand whether the observed events were connected, we compared air mass trajectories as well as meteorological conditions at both stations. Favorable conditions for the occurrence of regional NPF events were largely affected by air mass transport. Overall, our results demonstrate a clear inhomogeneity of regional NPF within a distance of ∼100 km, possibly due to the discretely distributed emission sources.

scholarly journals Measurement Report: New particle formation characteristics at an urban and a mountain station in Northern China

2021 ◽  
Author(s):  
Ying Zhou ◽  
Simo Hakala ◽  
Chao Yan ◽  
Yang Gao ◽  
Xiaohong Yao ◽  
...  
Keyword(s):  
Cloud Condensation Nuclei ◽  
Formation Rate ◽  
Regional Scale ◽  
Particle Formation ◽  
Urban Site ◽  
Anthropogenic Activity ◽  
New Particle Formation ◽  
Large Area ◽  
Air Mass ◽  
Mountain Site

Abstract. Atmospheric new particle formation (NPF) events have attracted increasing attention for their contribution to the global aerosol number budget, and therefore their effects on climate, air quality, and human health. NPF events are regarded as a regional phenomenon, occurring over a large area. However, the spatial variation of NPF intensity has not been investigated in detail by incorporating both urban and regional measurements. Urban environments have more heterogeneous and freshly emitted NPF precursors as compared to environments with less anthropogenic activity. Here, we provide a comparison of NPF event characteristics – NPF event frequency, particle formation rate, and growth rate – by comparing an urban Beijing site and a background mountain site separated by ~80 km from June 14 to July 14, 2019 as well as give insights into the connection between both locations. During the measurement period, 12 and 13 NPF events were observed at the urban and background mountain sites, respectively, with 9 NPF events observed on the same day at both sites. Although the median condensation sink during the first two hours of the common NPF events was around 0.01 s−1 at both sites, there were notable differences in particle formation rates between the two locations (median of 5.42 cm−3 s−1 at the urban site and 1.13 cm−3 s−1 at the mountain site during the first two hours of common NPF events). Yet, the particle growth rates in the 7–15 nm range for common NPF events were comparable (median of 7.6 nm.h−1 at the urban site and 6.5 nm.h−1 at the mountain site as median values). To understand whether the observed events were connected, we compared air mass trajectories as well as meteorological conditions at both stations. Favorable conditions for the occurrence of regional NPF events were largely affected by air mass transport. Overall, our results demonstrate a clear inhomogeneity of regional NPF within a distance of ~100 km, which should be considered in regional-scale aerosol models when estimating the budget of aerosol load and cloud condensation nuclei.

scholarly journals Global analysis of continental boundary layer new particle formation based on long-term measurements

2018 ◽  
Author(s):  
Tuomo Nieminen ◽  
Veli-Matti Kerminen ◽  
Tuukka Petäjä ◽  
Pasi P. Aalto ◽  
Mikhail Arshinov ◽  
...  
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Urban Areas ◽  
Global Analysis ◽  
Formation Rate ◽  
Particle Formation ◽  
Urban Environments ◽  
New Particle Formation ◽  
The World ◽  
Order Of Magnitude

Abstract. Atmospheric new particle formation (NPF) is an important phenomenon in terms of the global particle number concentrations. Here we investigated the frequency of NPF, formation rates of 10 nm particles and growth rates in the size range of 10–25 nm using at least one year of aerosol number size-distribution observations at 36 different locations around the world. The majority of these measurement sites are in the Northern Hemisphere. We found that the NPF frequency has a strong seasonal variability, taking place on about 30 % of the days in March–May and on about 10 % of the days in December–February. The median formation rate of 10 nm particles varies by about three orders of magnitude (0.01–10 cm−3 s−1) and the growth rate by about an order of magnitude (1–10 nm h−1). The smallest values of both formation and growth rates were observed at polar sites and the largest ones in urban environments or anthropogenically influenced rural sites. The correlation between the NPF event frequency and the particle formation and growth rate was at best moderate between the different measurement sites, as well as between the sites belonging to a certain environmental regime. For a better understanding of atmospheric NPF and its regional importance, we would need more observational data from different urban areas in practically all parts of the world, from additional remote and rural locations in Northern America, Asia and most of the Southern Hemisphere (especially Australia), from polar areas, and from at least a few locations over the oceans.

scholarly journals Characterization of ultrafine particle number concentration and new particle formation in urban environment of Taipei, Taiwan

2013 ◽  
Vol 13 (4) ◽  
pp. 8985-9016 ◽  
Author(s):  
H. C. Cheung ◽  
C. C.-K. Chou ◽  
W.-R. Huang ◽  
C.-Y. Tsai
Keyword(s):  
Growth Rate ◽  
Urban Areas ◽  
Formation Rate ◽  
Particle Formation ◽  
Number Concentration ◽  
New Particle Formation ◽  
Urban Background ◽  
Photo Oxidation ◽  
Nucleation Mode ◽  
Quadratic Relationship

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, PM (d ≤ 1 μm), and photolysis rate of ozone, J(O1D). The averaged number concentrations of total (Ntotal), accumulation mode (Nacu), Aitken mode (Ntotal), and nucleation mode (Nnuc) particles were 7.6 × 103 cm−3, 1.2 × 103 cm−3, 4.4 × 103 cm−3, and 1.9 × 103 cm−3, respectively. Accordingly, the ultrafine particles (UFPs, d ≤ 100 nm) accounted for 83% 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 ~60 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 the "urban background" levels during daytime, suggesting a substantial amount of nucleation mode particles produced from photochemical processes. Consistency in the time series of the nucleation mode particle concentration and the proxy of H2SO4 production, UVB·SO2, for new particle formation (NPF) events showed that photo-oxidation of SO2 was responsible for the formation of new particles in our study area. Moreover, analysis upon the diameter growth rate, GR, and formation rate of nucleation mode particles, J10−25, found that the values of GR (8.5 ± 6.8 nm h−1) in Taipei were comparable to other urban areas, whereas the values of J10−25 (2.2 ± 1.2 cm−3 s−1) observed in this study were around the low end of the range of new particle formation rate reported by previous investigations. It was revealed that the particle growth rate correlated exponentially with the photolysis of ozone, suggesting the condensable vapors were produced mostly from photo-oxidation reactions. In addition, this study also revealed that both GR and J10−25 exhibited quadratic relationship with the number concentration of particles. The quadratic relationship was inferred as a result of aerosol dynamics and featured NPF process in urban areas.

scholarly journals Global analysis of continental boundary layer new particle formation based on long-term measurements

2018 ◽  
Vol 18 (19) ◽  
pp. 14737-14756 ◽  
Author(s):  
Tuomo Nieminen ◽  
Veli-Matti Kerminen ◽  
Tuukka Petäjä ◽  
Pasi P. Aalto ◽  
Mikhail Arshinov ◽  
...  
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Urban Areas ◽  
Global Analysis ◽  
Formation Rate ◽  
Particle Formation ◽  
Urban Environments ◽  
New Particle Formation ◽  
The World ◽  
Order Of Magnitude

Abstract. Atmospheric new particle formation (NPF) is an important phenomenon in terms of global particle number concentrations. Here we investigated the frequency of NPF, formation rates of 10 nm particles, and growth rates in the size range of 10–25 nm using at least 1 year of aerosol number size-distribution observations at 36 different locations around the world. The majority of these measurement sites are in the Northern Hemisphere. We found that the NPF frequency has a strong seasonal variability. At the measurement sites analyzed in this study, NPF occurs most frequently in March–May (on about 30 % of the days) and least frequently in December–February (about 10 % of the days). The median formation rate of 10 nm particles varies by about 3 orders of magnitude (0.01–10 cm−3 s−1) and the growth rate by about an order of magnitude (1–10 nm h−1). The smallest values of both formation and growth rates were observed at polar sites and the largest ones in urban environments or anthropogenically influenced rural sites. The correlation between the NPF event frequency and the particle formation and growth rate was at best moderate among the different measurement sites, as well as among the sites belonging to a certain environmental regime. For a better understanding of atmospheric NPF and its regional importance, we would need more observational data from different urban areas in practically all parts of the world, from additional remote and rural locations in North America, Asia, and most of the Southern Hemisphere (especially Australia), from polar areas, and from at least a few locations over the oceans.

scholarly journals New particle formation events in semi-clean South African savannah

2010 ◽  
Vol 10 (12) ◽  
pp. 30777-30821 ◽  
Author(s):  
V. Vakkari ◽  
H. Laakso ◽  
M. Kulmala ◽  
A. Laaksonen ◽  
D. Mabaso ◽  
...  
Keyword(s):  
Growth Rate ◽  
Sulphuric Acid ◽  
Growth Rates ◽  
Formation Rate ◽  
Particle Formation ◽  
Size Distributions ◽  
New Particle Formation ◽  
Air Mass ◽  
History Analysis ◽  
Particle Formation And Growth

Abstract. This study is based on 18 months (20 July 2006–5 February 2008) of continuous measurements of aerosol particle size distributions, air ion size distributions, trace gas concentrations and basic meteorology in a semi-clean savannah environment in Republic of South Africa. New particle formation and growth was observed on 69% of the days and bursts of non-growing ions/sub-10 nm particles on additional 14% of the days. The new particle formation and growth rates were among the highest reported in the literature for continental boundary layer locations; median 10 nm formation rate was 2.2 cm−3s−1 and median 10–30 nm growth rate 8.9 nm h−1. The median 2 nm ion formation rate was 0.5 cm−3s−1 and the median ion growth rates were 6.2, 8.0 and 8.1 nm h−1 for size ranges 1.5–3 nm, 3–7 nm and 7–20 nm, respectively. Three different approaches were used to study the origin of the formation and growth rates: seasonal variation, air mass history analysis and estimated sulphuric acid contribution to the growth. The growth rates had a clear seasonal dependency with minimum during winter and maxima in spring and late summer and the air mass history analysis indicated the highest formation and growth rates to be associated with the area of highest VOC (Volatile Organic Compounds) emissions rather than the highest estimated sulphuric acid concentrations. The relative contribution of estimated sulphuric acid to the growth rate was decreasing with increasing particle size and could explain more than 20% of the observed growth rate only for the 1.5–3 nm size range. The implication is that the sulphuric acid alone is not enough to explain the growth, but the highest growth rates seem to originate in VOC emissions following from biological activity. The frequency of new particle formation, however, increased nearly monotonously with the estimated sulphuric acid reaching 100% at H2SO4 concentration of 4×107cm−3, which suggests the formation and growth to be independent of each other.

Connection of organics to atmospheric new particle formation and growth at an urban site of Beijing

2015 ◽  
Vol 103 ◽  
pp. 7-17 ◽  
Author(s):  
Z.B. Wang ◽  
M. Hu ◽  
X.Y. Pei ◽  
R.Y. Zhang ◽  
P. Paasonen ◽  
...  
Keyword(s):  
Particle Formation ◽  
Urban Site ◽  
New Particle Formation ◽  
Particle Formation And Growth

scholarly journals Long-term analysis of clear-sky new particle formation events and non-events in Hyytiälä

2016 ◽  
Author(s):  
Lubna Dada ◽  
Pauli Paasonen ◽  
Tuomo Nieminen ◽  
Stephany Buenrostro Mazon ◽  
Jenni Kontkanen ◽  
...  
Keyword(s):  
Formation Rate ◽  
Threshold Value ◽  
Particle Formation ◽  
New Particle Formation ◽  
Organic Vapors ◽  
Clear Sky ◽  
Sky Conditions ◽  
Oxidized Products ◽  
Condensation Sink

Abstract. New particle formation (NPF) events have been observed all around the world and are known to be a major source of atmospheric aerosol particles. Here we combine 20 years of observations in a boreal forest at the SMEAR II station (Station for Measuring Ecosystem-Atmosphere Relations) in Hyytiälä, Finland, by utilizing previously accumulated knowledge, and by focusing on clear-sky (non-cloudy) conditions. We first investigated the effect of cloudiness on NPF and then compared the NPF event and non-event days during clear-sky conditions. In this comparison we considered, for example, the effects of calculated particle formation rates, condensation sink, trace gas concentrations and various meteorological quantities. The formation rate of 1.5 nm particles was calculated by using proxies for gaseous sulfuric acid and oxidized products of low volatile organic compounds. As expected, our results indicate an increase in the frequency of NPF events under clear-sky conditions. Also, focusing on clearsky conditions enabled us to find a clear separation of many variables related to NPF. For instance, oxidized organic vapors showed higher concentration during the clear-sky NPF event days, whereas the condensation sink (CS) and some trace gases had higher concentrations during the non-event days. The calculated formation rate of 3 nm particles showed a notable difference between the NPF event and non-event days during clear-sky conditions, especially in winter and spring. For spring time, we are able to find a threshold value for the combined values of ambient temperature and CS, above which practically no clear-sky NPF event could be observed. Finally, we present a probability distribution for the frequency of NPF events at a specific CS and temperature.

scholarly journals Concentrations and fluxes of aerosol particles during the LAPBIAT measurement campaign at Värriö field station

2007 ◽  
Vol 7 (14) ◽  
pp. 3683-3700 ◽  
Author(s):  
T. M. Ruuskanen ◽  
M. Kaasik ◽  
P. P. Aalto ◽  
U. Hõrrak ◽  
M. Vana ◽  
...  
Keyword(s):  
Kola Peninsula ◽  
Aerosol Particle ◽  
Aerosol Particles ◽  
Particle Formation ◽  
Nucleation Event ◽  
New Particle Formation ◽  
Air Ions ◽  
Field Station ◽  
Air Mass ◽  
Measurement Campaign

Abstract. The LAPBIAT measurement campaign took place in the Värriö SMEAR I measurement station located in Eastern Lapland in the spring of 2003 between 26 April and 11 May. In this paper we describe the measurement campaign, concentrations and fluxes of aerosol particles, air ions and trace gases, paying special attention to an aerosol particle formation event broken by a air mass change from a clean Arctic air mass with new particle formation to polluted one approaching from industrial areas of Kola Peninsula, Russia, lacking new particle formation. Aerosol particle number flux measurements show strong downward fluxes during that time. Concentrations of coarse aerosol particles were high for 1–2 days before the nucleation event (i.e. 28–29 April), very low immediately before and during the observed aerosol particle formation event (30 April) and increased moderately from the moment of sudden break of the event. In general particle deposition measurements based on snow samples show the same changes. Measurements of the mobility distribution of air ions showed elevated concentrations of intermediate air ions during the particle formation event. We estimated the growth rates in the nucleation mode size range. For particles <10 nm, the growth rate increases with size on 30 April. Dispersion modelling made with model SILAM support the conclusion that the nucleation event was interrupted by an outbreak of sulphate-rich air mass in the evening of 30 April that originated from the industry at Kola Peninsula, Russia. The results of this campaign highlight the need for detailed research in atmospheric transport of air constituents for understanding the aerosol dynamics.

scholarly journals Characterization of Urban New Particle Formation in Amman—Jordan

Atmosphere ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 79 ◽  
Author(s):  
Tareq Hussein ◽  
Nahid Atashi ◽  
Larisa Sogacheva ◽  
Simo Hakala ◽  
Lubna Dada ◽  
...  
Keyword(s):  
Growth Rate ◽  
Eastern Mediterranean ◽  
Seasonal Pattern ◽  
Formation Rate ◽  
Particle Formation ◽  
New Particle Formation ◽  
Vapor Source ◽  
Back Trajectories ◽  
Pattern Maximum ◽  
The Mean

We characterized new particle formation (NPF) events in the urban background of Amman during August 2016–July 2017. The monthly mean of submicron particle number concentration was 1.2 × 104–3.7 × 104 cm−3 (exhibited seasonal, weekly, and diurnal variation). Nucleation mode (10–15 nm) concentration was 0.7 × 103–1.1 × 103 cm−3 during daytime with a sharp peak (1.1 × 103–1.8 × 103 cm−3) around noon. We identified 110 NPF events (≈34% of all days) of which 55 showed a decreasing mode diameter after growth. The NPF event occurrence was higher in summer than in winter, and events were accompanied with air mass back trajectories crossing over the Eastern Mediterranean. The mean nucleation rate (J10) was 1.9 ± 1.1 cm−3 s−1 (monthly mean 1.6–2.7 cm−3 s−1) and the mean growth rate was 6.8 ± 3.1 nm/h (4.1–8.8 nm/h). The formation rate did not have a seasonal pattern, but the growth rate had a seasonal variation (maximum around August and minimum in winter). The mean condensable vapor source rate was 4.1 ± 2.2 × 105 molecules/cm3 s (2.6–6.9 × 105 molecules/cm3 s) with a seasonal pattern (maximum around August). The mean condensation sink was 8.9 ± 3.3 × 10−3 s−1 (6.4–14.8 × 10−3 s−1) with a seasonal pattern (minimum around June and maximum in winter).

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