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

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.

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

Atmospheric Chemistry and Physics ◽

10.5194/acp-11-12959-2011 ◽

2011 ◽

Vol 11 (24) ◽

pp. 12959-12972 ◽

Cited By ~ 59

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

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Atmospheric new particle formation as source of CCN in the Eastern Mediterranean marine boundary layer

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-15-11143-2015 ◽

2015 ◽

Vol 15 (7) ◽

pp. 11143-11178 ◽

Cited By ~ 1

Author(s):

N. Kalivitis ◽

V.-M. Kerminen ◽

G. Kouvarakis ◽

I. Stavroulas ◽

A. Bougiatioti ◽

...

Keyword(s):

Organic Material ◽

Marine Boundary Layer ◽

Size Range ◽

Eastern Mediterranean ◽

Cloud Condensation Nuclei ◽

Cloud Droplet ◽

Particle Formation ◽

New Particle Formation ◽

Multiple Sources ◽

Marine Air

Abstract. While Cloud Condensation Nuclei (CCN) production associated with atmospheric new particle formation (NPF) is thought to be frequent throughout the continental boundary layers, few studies on this phenomenon in marine air exist. Here, based on simultaneous measurement of particle number size distributions, CCN properties and aerosol chemical composition, we present the first direct evidence on CCN production resulting from NPF in the Eastern Mediterranean atmosphere. We show that condensation of both gaseous sulfuric acid and organic compounds from multiple sources leads to the rapid growth of nucleated particles to CCN sizes in this environment during the summertime. Sub-100 nm particles were found to be substantially less hygroscopic than larger particles during the period with active NPF and growth (0.2–0.4 lower κ between the 60 and 120 nm particles), probably due to enrichment of organic material in the sub-100 nm size range. The aerosol hygroscopicity tended to be at minimum just before the noon and at maximum in afternoon, which was very likely due to the higher sulfate to organic ratios and higher degree of oxidation of the organic material during the afternoon. Simultaneously to the formation of new particles during daytime, particles formed in the previous day or even earlier were growing into the size range relevant to cloud droplet activation, and the particles formed in the atmosphere were possibly mixed with long-range transported particles.

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Atmospheric new particle formation as a source of CCN in the eastern Mediterranean marine boundary layer

Atmospheric Chemistry and Physics ◽

10.5194/acp-15-9203-2015 ◽

2015 ◽

Vol 15 (16) ◽

pp. 9203-9215 ◽

Cited By ~ 24

Author(s):

N. Kalivitis ◽

V.-M. Kerminen ◽

G. Kouvarakis ◽

I. Stavroulas ◽

A. Bougiatioti ◽

...

Keyword(s):

Organic Material ◽

Marine Boundary Layer ◽

Size Range ◽

Eastern Mediterranean ◽

Cloud Condensation Nuclei ◽

Cloud Droplet ◽

Particle Formation ◽

New Particle Formation ◽

Multiple Sources ◽

Marine Air

Abstract. While cloud condensation nuclei (CCN) production associated with atmospheric new particle formation (NPF) is thought to be frequent throughout the continental boundary layers, few studies on this phenomenon in marine air exist. Here, based on simultaneous measurement of particle number size distributions, CCN properties and aerosol chemical composition, we present the first direct evidence on CCN production resulting from NPF in the eastern Mediterranean atmosphere. We show that condensation of both gaseous sulfuric acid and organic compounds from multiple sources leads to the rapid growth of nucleated particles to CCN sizes in this environment during the summertime. Sub-100 nm particles were found to be substantially less hygroscopic than larger particles during the period with active NPF and growth (the value of κ was lower by 0.2–0.4 for 60 nm particles compared with 120 nm particles), probably due to enrichment of organic material in the sub-100 nm size range. The aerosol hygroscopicity tended to be at minimum just before the noon and at maximum in the afternoon, which was very likely due to the higher sulfate-to-organic ratios and higher degree of oxidation of the organic material during the afternoon. Simultaneous with the formation of new particles during daytime, particles formed during the previous day or even earlier were growing into the size range relevant to cloud droplet activation, and the particles formed in the atmosphere were possibly mixed with long-range-transported particles.

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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

Atmospheric Chemistry and Physics ◽

10.5194/acp-20-5911-2020 ◽

2020 ◽

Vol 20 (10) ◽

pp. 5911-5922 ◽

Cited By ~ 4

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.

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New particle formation in air mass transported between two measurement sites in Northern Finland

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-5-11929-2005 ◽

2005 ◽

Vol 5 (6) ◽

pp. 11929-11963 ◽

Cited By ~ 1

Author(s):

M. Komppula ◽

S.-L. Sihto ◽

H. Korhonen ◽

H. Lihavainen ◽

V.-M. Kerminen ◽

...

Keyword(s):

Growth Rates ◽

Particle Growth ◽

Particle Formation ◽

Distribution Data ◽

New Particle Formation ◽

Air Mass ◽

Air Masses ◽

Aerosol Dynamics ◽

Almost All ◽

Distinct Features

Abstract. This study covers four years of aerosol number size distribution data from Pallas and Värriö sites 250 km apart from each other in Northern Finland and compares new particle formation events between these sites. In eastern air masses almost all events were observed to start earlier at the eastern station Värriö, whereas in western air masses most of the events were observed to start earlier at the western station Pallas. This demonstrates that particle formation in a certain air mass type depends not only on the diurnal variation of the parameters causing the phenomenon (such as photochemistry) but also on some properties carried by the air mass itself. The correlation in growth rates between the two sites was relatively good, which suggests that the amount of condensable vapour causing the growth must have been at about the same level in both sites. The value of condensation sink was frequently much higher at the downwind station. It seems that secondary particle formation related to biogenic sources dominate in many cases over the particle sinks during the air mass transport between the sites. Two cases of transport from Pallas to Värriö were further analysed with an aerosol dynamics model. The model was able to reproduce the observed nucleation events 250 km down-wind at Värriö but revealed some differences between the two cases. The simulated nucleation rates were in both cases similar but the organic concentration profiles that best reproduced the observations were different in the two cases indicating that divergent formation reactions may dominate under different conditions. The simulations also suggested that organic compounds were the main contributor to new particle growth, which offers a tentative hypothesis to the distinct features of new particles at the two sites: Air masses arriving from Atlantic Ocean typically spent approximately only ten hours over land before arriving at Pallas, and thus the time for the organic vapours to accumulate in the air and to interact with the particles is relatively short. This can lead to low nucleation mode growth rates and even to suppression of detectable particle formation event due to efficient scavenging of newly formed clusters, as was observed in the case studies.

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Evaluation of the contribution of new particle formation to cloud droplet in urban atmosphere

10.5194/acp-2021-23 ◽

2021 ◽

Author(s):

Sihui Jiang ◽

Fang Zhang ◽

Jingye Ren ◽

Lu Chen ◽

Xing Yan ◽

...

Keyword(s):

Water Vapor ◽

Cloud Condensation Nuclei ◽

Aerosol Particles ◽

Cloud Droplet ◽

Particle Formation ◽

Urban Atmosphere ◽

Primary Sources ◽

New Particle Formation ◽

Multiple Sources ◽

Considerable Impact

Abstract. New particle formation (NPF) is a large source of cloud condensation nuclei (CCN) and cloud droplet in the troposphere. In this study, we quantified the contribution of NPF to cloud droplet number concentration (CDNC, or Nd) at typical updraft velocities (V) in clouds using a field campaign data of aerosol number size distribution and chemical composition observed on May 25–June 18, 2017 in urban Beijing. We show that the NPF drives the variations of CCN and cloud droplet and increases Nd by 30–33 % at V = 0.3–3 m s−1 in urban atmosphere. A markedly reduction in Nd is observed due to water vapor competition with consideration of actual environmental updraft velocity, decreasing by 11.8 ± 5.0 % at V = 3 m s−1 and 19.0 ± 4.5 % at V = 0.3 m s−1 compared to that from a prescribed supersaturation. The effect of water vapor competition becomes smaller at larger V that can provide more sufficient water vapor. Essentially, water vapor competition led to the reduction in Nd by decreasing the environmental maximum supersaturation (Smax) for the activation of aerosol particles. It is shown that Smax was decreased by 14.5–11.7 % for V = 0.3–3 m s−1. Particularly, the largest suppression of cloud droplet formation due to the water vapor competition is presented at extremely high aerosol particle number concentrations. As a result, although a larger increase of CCN-size particles by NPF event is derived on clean NPF day when pre-existing background aerosol particles are very low, there is no large discrepancy in the enhancement of Nd by NPF between the clean and polluted NPF day. We finally show a considerable impact of the primary sources when evaluating the NPF contribution to cloud droplet based on a case study. Our study highlights the importance of fully consideration of both the environmental meteorological conditions and multiple sources (i.e. secondary and primary) to evaluate the NPF effect on clouds and the associated climate effects in polluted regions.

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Basic characteristics of atmospheric particles, trace gases and meteorology in a relatively clean Southern African Savannah environment

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-8-6313-2008 ◽

2008 ◽

Vol 8 (2) ◽

pp. 6313-6353 ◽

Cited By ~ 1

Author(s):

L. Laakso ◽

H. Laakso ◽

P. P. Aalto ◽

P. Keronen ◽

T. Petäjä ◽

...

Keyword(s):

Growth Rates ◽

Cloud Condensation Nuclei ◽

Regional Climate ◽

Formation Rate ◽

Measurement Data ◽

Particle Growth ◽

Particle Formation ◽

New Particle Formation ◽

Total Particle ◽

Pm2.5 And Pm10

Abstract. We have analyzed one year (July 2006–July 2007) of measurement data from a relatively clean background site located in dry savannah in South Africa. The annual-median trace gas concentrations were equal to 0.7 ppb for SO2, 1.4 ppb for NOx, 36 ppb for O3 and 105 ppb for CO. The corresponding PM1, PM2.5 and PM10 concentrations were 9.0, 10.5 and 18.8 μg m−3, and the annual median total particle number concentration in the size range 10–840 nm was 2340 cm−3. Gases and particles had a clear seasonal and diurnal variation, which was associated with field fires and biological activity together with local meteorology. Atmospheric new-particle formation was observed to take place in more than 90% of the analyzed days. The days with no new particle formation were cloudy or rainy days. The formation rate of 10 nm particles varied in the range of 0.1–28 cm−3 s−1 (median 1.9 cm−3 s−1) and nucleation mode particle growth rates were in the range 3–21 nm h−1 (median 8.5 nm h−1). Due to high formation and growth rates, observed new particle formation gives a significant contribute to the number of cloud condensation nuclei budget, having a potential to affect the regional climate forcing patterns.

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Molecular understanding of the suppression of new-particle formation by isoprene

10.5194/acp-2020-51 ◽

2020 ◽

Cited By ~ 1

Author(s):

Martin Heinritzi ◽

Lubna Dada ◽

Mario Simon ◽

Dominik Stolzenburg ◽

Andrea C. Wagner ◽

...

Keyword(s):

Growth Rates ◽

Cloud Condensation Nuclei ◽

Formation Rate ◽

Organic Aerosol ◽

Particle Formation ◽

Early Growth ◽

Chemical System ◽

Particle Nucleation ◽

New Particle Formation ◽

Ambient Conditions

Abstract. Nucleation of atmospheric vapors produces more than half of global cloud condensation nuclei and so has an important influence on climate. Recent studies show that monoterpene (C10H16) oxidation yields highly-oxygenated products that can nucleate with or without sulfuric acid. Monoterpenes are emitted mainly by trees, frequently together with isoprene (C5H8), which has the highest global emission of all organic vapors. Previous studies have shown that isoprene suppresses new-particle formation from monoterpenes, but the cause of this suppression is under debate. Here, in experiments performed under atmospheric conditions in the CERN CLOUD chamber, we show that isoprene reduces the yield of highly-oxygenated dimers with 19 or 20 carbon atoms – which drive particle nucleation and early growth – while increasing the production of dimers with 14 or 15 carbon atoms. The dimers (termed C20 and C15, respectively) are produced by termination reactions between pairs of peroxy radicals (RO2·) arising from monoterpenes or isoprene. Compared with pure monoterpene conditions, isoprene reduces nucleation rates at 1.7 nm (depending on the isoprene/monoterpene ratio) and approximately halves particle growth rates between 1.3 and 3.2 nm. However, above 3.2 nm, C15 dimers contribute to secondary organic aerosol and the growth rates are unaffected by isoprene. We further show that increased hydroxyl radical (OH·) reduces particle formation in our chemical system rather than enhances it as previously proposed, since it increases isoprene derived RO2· radicals that reduce C20 formation. RO2· termination emerges as the critical step that determines the HOM distribution and the corresponding nucleation capability. Species that reduce the C20 yield, such as NO, HO2 and as we show isoprene, can thus effectively reduce biogenic nucleation and early growth. Therefore the formation rate of organic aerosol in a particular region of the atmosphere under study will vary according to the precise ambient conditions.

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Analysis of new particle formation (NPF) events at nearby rural, urban background and urban roadside sites

Atmospheric Chemistry and Physics ◽

10.5194/acp-19-5679-2019 ◽

2019 ◽

Vol 19 (8) ◽

pp. 5679-5694 ◽

Cited By ~ 8

Author(s):

Dimitrios Bousiotis ◽

Manuel Dall'Osto ◽

David C. S. Beddows ◽

Francis D. Pope ◽

Roy M. Harrison

Keyword(s):

Urban Environment ◽

Growth Rates ◽

General Pattern ◽

Particle Growth ◽

Particle Formation ◽

Atmospheric Conditions ◽

New Particle Formation ◽

Urban Background ◽

Air Masses ◽

Condensation Sink

Abstract. New particle formation (NPF) events have different patterns of development depending on the conditions of the area in which they occur. In this study, particle size distributions in the range of 16.6–604 nm (7 years of data) were analysed and NPF events occurring at three sites of differing characteristics – rural Harwell (HAR), urban background North Kensington (NK), urban roadside Marylebone Road (MR), London, UK – were extracted and studied. The different atmospheric conditions in each study area not only have an effect on the frequency of the events, but also affect their development. The frequency of NPF events is similar at the rural and urban background locations (about 7 % of days), with a high proportion of events occurring at both sites on the same day (45 %). The frequency of NPF events at the urban roadside site is slightly less (6 % of days), and higher particle growth rates (average 5.5 nm h−1 at MR compared to 3.4 and 4.2 nm h−1 at HAR and NK respectively) must result from rapid gas-to-particle conversion of traffic-generated pollutants. A general pattern is found in which the condensation sink increases with the degree of pollution of the site, but this is counteracted by increased particle growth rates at the more polluted location. A key finding of this study is that the role of the urban environment leads to an increment of 20 % in N16–20 nm in the urban background compared to that of the rural area in NPF events occurring at both sites. The relationship of the origin of incoming air masses is also considered and an association of regional events with cleaner air masses is found. Due to lower availability of condensable species, NPF events that are associated with cleaner atmospheric conditions have lower growth rates of the newly formed particles. The decisive effect of the condensation sink in the development of NPF events and the survivability of the newly formed particles is underlined, and influences the overall contribution of NPF events to the number of ultrafine particles in an area. The other key factor identified by this study is the important role that pollution, both from traffic and other sources in the urban environment (such as heating or cooking), plays in new particle formation events.

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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

10.5194/acp-2019-519 ◽

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.

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