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

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

Atmospheric Chemistry and Physics ◽

10.5194/acp-21-14293-2021 ◽

2021 ◽

Vol 21 (18) ◽

pp. 14293-14308

Author(s):

Sihui Jiang ◽

Fang Zhang ◽

Jingye Ren ◽

Lu Chen ◽

Xing Yan ◽

...

Keyword(s):

Water Vapor ◽

Cloud Condensation Nuclei ◽

Cloud Droplet ◽

Particle Formation ◽

Number Concentration ◽

Urban Atmosphere ◽

New Particle Formation ◽

High Background ◽

Effect Of Water ◽

Cloud Droplet Number Concentration

Abstract. The effect of new particle formation (NPF) on cloud condensation nuclei (CCN) varies widely in diverse environments. CCN or cloud droplets from NPF sources remain highly uncertain in the urban atmosphere; they are greatly affected by the high background aerosols and frequent local emissions. In this study, we quantified the effect of NPF on cloud droplet number concentration (CDNC, or Nd) at typical updraft velocities (V) in clouds based on field observations on 25 May–18 June 2017 in urban Beijing. We show that NPF increases the Nd by 32 %–40 % at V=0.3–3 m s−1 during the studied period. The Nd is reduced 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 calculated from constant supersaturations due to the water vapor competition effect, which suppresses the cloud droplet formation by decreasing the environmental maximum supersaturation (Smax). The effect of water vapor competition becomes smaller at larger V that can provide more sufficient water vapor. However, under extremely high aerosol particle number concentrations, the effect of water vapor competition becomes more pronounced. As a result, although a larger increase of CCN-sized particles by NPF events is derived on clean NPF days when the number concentration of preexisting background aerosol particles is very low, no large discrepancy is presented in the enhancement of Nd by NPF between clean and polluted NPF days. We finally reveal a considerable impact of the primary sources on the evaluation of the contribution of NPF to CCN number concentration (NCCN) and Nd based on a case study. Our study highlights the importance of full consideration of both the environmental meteorological conditions and multiple sources (i.e., secondary and primary) to evaluate the effect of NPF on clouds and the associated climate effects in polluted regions.

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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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New particle formation in the southern Aegean Sea during the Etesians: importance for CCN production and cloud droplet number

Atmospheric Chemistry and Physics ◽

10.5194/acp-17-175-2017 ◽

2017 ◽

Vol 17 (1) ◽

pp. 175-192 ◽

Cited By ~ 21

Author(s):

Panayiotis Kalkavouras ◽

Elissavet Bossioli ◽

Spiros Bezantakos ◽

Aikaterini Bougiatioti ◽

Nikos Kalivitis ◽

...

Keyword(s):

Water Vapor ◽

Eastern Mediterranean ◽

Cloud Condensation Nuclei ◽

Cloud Droplet ◽

Aegean Sea ◽

Particle Formation ◽

Cloud Formation ◽

Particle Nucleation ◽

Surface Winds ◽

New Particle Formation

Abstract. This study examines how new particle formation (NPF) in the eastern Mediterranean in summer affects CCN (cloud condensation nuclei) concentrations and cloud droplet formation. For this, the concentration and size distribution of submicron aerosol particles, along with the concentration of trace gases and meteorological variables, were studied over the central (Santorini) and southern Aegean Sea (Finokalia, Crete) from 15 to 28 July 2013, a period that includes Etesian events and moderate northern surface winds. Particle nucleation bursts were recorded during the Etesian flow at both stations, with those observed at Santorini reaching up to 1.5  ×  104 particles cm−3; the fraction of nucleation-mode particles over Crete was relatively diminished, but a higher number of Aitken-mode particles were observed as a result of aging. Aerosol and photochemical pollutants covaried throughout the measurement period; lower concentrations were observed during the period of Etesian flow (e.g., 43–70 ppbv for ozone and 1.5–5.7 µg m−3 for sulfate) but were substantially enhanced during the period of moderate surface winds (i.e., increase of up to 32 for ozone and 140 % for sulfate). We find that NPF can double CCN number (at 0.1 % supersaturation), but the resulting strong competition for water vapor in cloudy updrafts decreases maximum supersaturation by 14 % and augments the potential droplet number only by 12 %. Therefore, although NPF events may strongly elevate CCN numbers, the relative impacts on cloud droplet number (compared to pre-event levels) is eventually limited by water vapor availability and depends on the prevailing cloud formation dynamics and the aerosol levels associated with the background of the region.

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New Particle Formation in the South Aegean Sea during the Etesians: importance for CCN production and cloud droplet number

10.5194/acp-2016-330 ◽

2016 ◽

Cited By ~ 2

Author(s):

P. Kalkavouras ◽

E. Bossioli ◽

S. Bezantakos ◽

A. Bougiatioti ◽

N. Kalivitis ◽

...

Keyword(s):

Water Vapor ◽

Cloud Droplet ◽

Aegean Sea ◽

Particle Formation ◽

Number Concentration ◽

Cloud Formation ◽

Particle Nucleation ◽

New Particle Formation ◽

Cloud Droplet Number Concentration ◽

Measurement Period

Abstract. We examine the concentration levels and size distribution of submicron aerosol particles along with the concentration of trace gases and meteorological variables over the central (Santorini) and south Aegean Sea (Crete) from 15 to 28 July 2013, a period that includes Etesian events and moderate northern winds. Particle nucleation bursts were recorded during the Etesian flow at both stations, with those observed at Santorini reaching up to 1.5 × 104 particles cm−3. On Crete (at Finokalia station), the fraction of nucleation-mode particles was diminished, but a higher number of Aitken-mode was observed as a result of the downward mixing and photochemistry. Aerosol and photochemical pollutants covaried throughout the measurement period: lower concentrations were observed during the period of strong Etesian flow (e.g. 43–70 ppbv for ozone, 1.5–5.7 μg m−3 for sulfate), but were substantially enhanced during the period of moderate winds (i.e., increase of up to 32 % for ozone, and 140 % for sulfate). To understand how new particle formation (NPF) affects cloud formation, we quantify its impact on the CCN levels and cloud droplet number concentration. We find that NPF can double CCN number (at 0.1 % supersaturation) but the resulting strong competition for water vapor in cloudy updrafts decreases maximum supersaturation by 14 % and augments the potential droplet number only by 12 %. Therefore, although NPF events may strongly elevate CCN numbers, the relative impacts on cloud droplet number (compared to pre-event levels) is eventually limited by water vapor availability and depends on the prevailing cloud formation dynamics and the aerosol levels associated with the background in the region.

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Studying new particle formation from chemical emissions from sea surface using ship-borne air-sea-interaction tanks

10.5194/egusphere-egu21-8110 ◽

2021 ◽

Author(s):

Maija Peltola ◽

Manon Rocco ◽

Neill Barr ◽

Erin Dunne ◽

James Harnwell ◽

...

Keyword(s):

Marine Biology ◽

Cloud Condensation Nuclei ◽

Aerosol Particles ◽

Chemical Species ◽

Particle Formation ◽

Biological Properties ◽

The European Union ◽

New Particle Formation ◽

Aerosol Formation ◽

Horizon 2020

Even though oceans cover over 70% of the Earth&#8217;s surface, the ways in which oceans interact with climate are not fully known. Marine micro-organisms such as phytoplankton can play an important role in regulating climate by releasing different chemical species into air. In air these chemical species can react and form new aerosol particles. If grown to large enough sizes, aerosols can influence climate by acting as cloud condensation nuclei which influence the formation and properties of clouds. Even though a connection of marine biology and climate through aerosol formation was first proposed already over 30 years ago, the processes related to this connection are still uncertain.To unravel how seawater properties affect aerosol formation and to identify which chemical species are responsible for aerosol formation, we built two Air-Sea-Interaction Tanks (ASIT) that isolate 1000 l of seawater and 1000 l of air directly above the water. The used seawater was collected from different locations during a ship campaign on board the R/V Tangaroa in the South West Pacific Ocean, close to Chatham Rise, east of New Zealand. Seawater from one location was kept in the tanks for 2-3 days and then changed. By using seawater collected from different locations, we could obtain water with different biological populations. To monitor the seawater, we took daily samples to determine its chemical and biological properties.The air in the tanks was continuously flushed with particle filtered air. This way the air had on average 40 min to interact with the seawater surface before being sampled. Our air sampling was continuous and consisted of aerosol and air chemistry measurements. The instrumentation included measurements of aerosol number concentration from 1 to 500 nm and&#160; chemical species ranging from ozone and sulphur dioxide to volatile organic compounds and chemical composition of molecular clusters.Joining the seawater and atmospheric data together can give us an idea of what chemical species are emitted from the water into the atmosphere and whether these species can form new aerosol particles. Our preliminary results show a small number of particles in the freshly nucleated size range of 1-3 nm in the ASIT headspaces, indicating that new aerosol particles can form in the ASIT headspaces. In this presentation, we will also explore which chemical species could be responsible for aerosol formation and which plankton groups could be related to the emissions of these species. Combining these results with ambient data and modelling work can shed light on how important new particle formation from marine sources is for climate.Acknowledgements: Sea2Cloud project is funded by European Research Council (ERC) under the European Union&#8217;s Horizon 2020 research and innovation programme (Grant agreement No. 771369).

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New particle formation events observed at King Sejong Station, Antarctic Peninsula – Part 1: Physical characteristics and contribution to cloud condensation nuclei

10.5194/acp-2018-1180 ◽

2018 ◽

Author(s):

Jaeseok Kim ◽

Young Jun Yoon ◽

Yeontae Gim ◽

Jin Hee Choi ◽

Hyo Jin Kang ◽

...

Keyword(s):

Antarctic Peninsula ◽

Cloud Condensation Nuclei ◽

Aerosol Particles ◽

Particle Formation ◽

Physical Characteristics ◽

Weddell Sea ◽

New Particle Formation ◽

Condensation Nuclei ◽

Source Rate ◽

The Mean

Abstract. The physical characteristics of aerosol particles during a particle burst observed at King Sejong Station in Antarctic Peninsula from March 2009 to December 2016 were analyzed. This study focuses on the seasonal variation in parameters related to particle formation such as the occurrence, formation rate (FR) and growth rate (GR), condensation sink (CS), and source rate of condensable vapor. The number concentrations during new particle formation (NPF) events varied from 1707 cm−3 to 83 120 cm−3, with an average of 20 649 ± 9290 cm−3, and the duration of the NPF events ranged from 0.6 h to 14.4 h, with a mean of 4.6 ± 1.5 h. The NPF event dominantly occurred during austral summer period (~ 72 %). The mean values of FR and GR of the aerosol particles were 2.79 ± 1.05 cm−3 s−1 and 0.68 ± 0.27 nm h−1, respectively showing enhanced rates in the summer season. The mean value of FR at King Sejong Station was higher than that at other sites in Antarctica, at 0.002–0.3 cm−3 s−1, while those of growth rates was relatively similar results observed by precious studies, at 0.4~4.3 nm h−1. The average values of CS and source rate of condensable vapor were (6.04 ± 2.74) × 10−3 s−1 and (5.19 ± 3.51) × 104 cm−3 s−1, respectively. The contribution of particle formation to cloud condensation nuclei (CCN) concentration was also investigated. The CCN concentration during the NPF period increased approximately 9 % compared with the background concentration. In addition, the effects of the origin and pathway of air masses on the characteristics of aerosol particles during a NPF event were determined. The FRs were similar regardless of the origin and pathway, whereas the GRs of particles originating from the Antarctic Peninsula and the Bellingshausen Sea, at 0.77 ± 0.25 nm h−1 and 0.76 ± 0.30 nm h−1, respectively, were higher than those of particles originating from the Weddell Sea (0.41 ± 0.15 nm h−1).

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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

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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Investigating three patterns of new particles growing to cloud condensation nuclei size in Beijing's urban atmosphere

10.5194/acp-2019-1151 ◽

2020 ◽

Author(s):

Liya Ma ◽

Yujiao Zhu ◽

Mei Zheng ◽

Yele Sun ◽

Lei Huang ◽

...

Keyword(s):

Cloud Condensation Nuclei ◽

Particle Formation ◽

Urban Atmosphere ◽

New Particle Formation ◽

Condensation Nuclei ◽

Median Diameter ◽

New Particles

Abstract. The growth of newly formed particles with diameters from ~ 10 nm to a larger size was investigated in Beijing's urban atmosphere on 10–23 December 2011, 12–27 April 2012 and through June–August 2014. The maximum geometric median diameter (Dpgmax) of newly formed particles in 11/27 new particle formation (NPF) events through June–August exceeded 75 nm, and the grown new particles may contribute to the population of cloud condensation nuclei. In contrast, no apparent growth in new particles with Dpgmax

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New particle formation events persistently reduce cloud droplets in boundary layer clouds

10.5194/egusphere-egu2020-13194 ◽

2020 ◽

Author(s):

David Patoulias ◽

Kalliopi Florou ◽

Spyros N. Pandis ◽

Athanasios Nenes

Keyword(s):

Cloud Condensation Nuclei ◽

Cloud Droplet ◽

Particle Formation ◽

New Particle Formation ◽

Cloud Droplets ◽

Convective Clouds ◽

Boundary Layer Clouds ◽

Stratiform Clouds ◽

Local Warming ◽

Climate Cooling

&#913; considerable fraction of cloud condensation nuclei (CCN) originates from new particle formation (NPF). Because of this, NPF events themselves are thought to also increase CCN and cloud droplet number (CDN) and contribute to climate cooling. High resolution state-of-the-art simulations over Europe however portray a different view: radiatively important stratiform clouds influenced by NPF events experience a systematic and substantial decrease in droplet number during and after nucleation events. The drop in CDN occurs because particles present prior to the NPF experiences slower growth during and after each event (as the condensable material is consumed by the growth of the NPF particles that do not typically activate), leading to fewer CCN at the low supersaturation levels characteristic of stratiform clouds (~0.1%). Convective clouds, however, tend to experience a modest increase in cloud droplet number &#8211; consistent with established views on the NPF-cloud link. Our results are corroborated by published observational evidence and all together reshape our conceptual understanding of NPF events on clouds, where droplets in stratiform clouds tend to be reduced (leading to local warming from reductions in cloud albedo) but enhance in convection. Combined, these effects could bear important impacts on cloud structure following NPF events.

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