Variability of air ion concentrations in urban Paris

Santos, Vanessa Nascimento dos; Herrmann, Erik; Manninen, Hanna E.; Hussein, Tareq; Hakala, J.; Nieminen, Tuomo; Aalto, Pasi; Merkel, Maik; Wiedensohler, Alfred; Kulmala, Markku; Petäj̈ä, Tuukka; Hämeri, Kaarle

doi:10.5194/acp-15-13717-2015

Cited by 21 publications

(8 citation statements)

References 86 publications

(133 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In order to derive the maximum particle concentration, we plotted the time series of the PNC in different size ranges. We estimated the GR from the slope of the best-fitted line on the graph of mid-point diameter of particles versus the time of maximum concentration (Dos Santos et al, 2015;Pierce et al, 2014).…”

Section: Calculation Of Particles Growth Ratementioning

confidence: 99%

Differentiating between particle formation and growth events in an urban environment

2018

View full text Add to dashboard Cite

Abstract. Small aerosols at a given location in the atmosphere often originate in situ from new particle formation (NPF). However, they can also be produced and then transported from a distant location to the point of observation where they may continue to grow to larger sizes. This study was carried out in the subtropical urban environment of Brisbane, Australia, in order to assess the relative occurrence frequencies of NPF events and particle growth events with no NPF. We used a neutral cluster and air ion spectrometer (NAIS) to monitor particles and ions in the size range 2–42 nm on 485 days, and identified 236 NPF events on 213 days. The majority of these events (37 %) occurred during the daylight hours with just 10 % at night. However, the NAIS also showed particle growth with no NPF on many nights (28 %). Using a scanning mobility particle sizer (SMPS), we showed that particle growth continued at larger sizes and occurred on 70 % of nights, typically under high relative humidities. Most particles in the air, especially near coastal locations, contain hygroscopic salts such as sodium chloride that may exhibit deliquescence when the relative humidity exceeds about 75 %. The growth rates of particles at night often exceeded the rates observed during NPF events. Although most of these night time growth events were preceded by day time NPF events, the latter was not a prerequisite for growth. We conclude that particle growth in the atmosphere can be easily misidentified as NPF, especially when they are monitored by an instrument that cannot detect them at the very small sizes.

show abstract

Section: Calculation Of Particles Growth Ratementioning

confidence: 99%

Differentiating between particle formation and growth events in an urban environment

2018

View full text Add to dashboard Cite

show abstract

“…Cloud condensation nuclei are emitted to the atmosphere directly from both anthropogenic and biogenic sources (Després et al, 2012), but a significant fraction of CCN are formed by condensation growth of smaller particles (Merikanto et al, 2009;Kerminen et al, 2012;Paasonen et al, 2013;Dunne et al, 2016;Gordon et al, 2017). These smaller particles may originate from atmospheric new particle formation (NPF), anthropogenic combustion or other emissions.…”

mentioning

confidence: 99%

Comprehensive analysis of particle growth rates from nucleation mode to cloud condensation nuclei in boreal forest

et al. 2018

Self Cite

View full text Add to dashboard Cite

Abstract. Growth of aerosol particles to sizes at which they can act as cloud condensation nuclei (CCN) is a crucial factor in estimating the current and future impacts of aerosol–cloud–climate interactions. Growth rates (GRs) are typically determined for particles with diameters (dP) smaller than 40 nm immediately after a regional new particle formation (NPF) event. These growth rates are often taken as representatives for the particle growth to CCN sizes (dP > 50–100 nm). In modelling frameworks, the concentration of the condensable vapours causing the growth is typically calculated with steady state assumptions, where the condensation sink (CS) is the only loss term for the vapours. Additionally, the growth to CCN sizes is represented with the condensation of extremely low-volatility vapours and gas–particle partitioning of semi-volatile vapours. Here, we use a novel automatic method to determine growth rates from below 10 nm to hundreds of nanometres from a 20-year-long particle size distribution (PSD) data set in boreal forest. With this method, we are able to detect growth rates also at times other than immediately after a NPF event. We show that the GR increases with an increasing oxidation rate of monoterpenes, which is closely coupled with the ambient temperature. Based on our analysis, the oxidation reactions of monoterpenes with ozone, hydroxyl radical and nitrate radical all are capable of producing vapours that contribute to the particle growth in the studied size ranges. We find that GR increases with particle diameter, resulting in up to 3-fold increases in GRs for particles with dP ∼ 100 nm in comparison to those with dP ∼ 10 nm. We use a single particle model to show that this increase in GR can be explained with aerosol-phase reactions, in which semi-volatile vapours form non-volatile dimers. Finally, our analysis reveals that the GR of particles with dP < 100 nm is not limited by the condensation sink, even though the GR of larger particles is. Our findings suggest that in the boreal continental environment, the formation of CCN from NPF or sub-100 nm emissions is more effective than previously thought and that the formation of CCN is not as strongly self-limiting a process as the previous estimates have suggested.

show abstract

“…Cloud condensation nuclei are emitted to the atmosphere directly from both anthropogenic (Paasonen et al, 2016) and biogenic sources (Després et al, 2012), but a significant fraction of CCN are formed by condensation growth of smaller particles (Merikanto et al, 2009;Kerminen et al, 2012;Paasonen et al, 2013;Dunne et al, 2016;Gordon et al, 2017). These smaller particles may originate from atmospheric new particle formation (NPF), anthropogenic combustion or other emissions.…”

Section: P Paasonen Et Al: Biogenic Growth Of Aerosols To Cloud Conmentioning

confidence: 99%

Comprehensive analysis of particle growth rates from nucleation mode to cloud condensation nuclei in Boreal forest

Paasonen¹,

Peltola²,

Kontkanen³

et al. 2018

Preprint

Self Cite

View full text Add to dashboard Cite

Abstract. Growth of aerosol particles to sizes at which they can act as cloud condensation nuclei (CCN) is a crucial factor in estimating the current and future impacts of aerosol cloud climate interactions. Growth rates are typically determined for particles with diameters (dP) smaller than 40&#8201;nm immediately after a regional new particle formation (NPF) event. These growth rates are often taken as representatives for the particle growth until CCN sizes (dP > 50&#8211;100&#8201;nm). In modelling frameworks, the concentration of the condensable vapours causing the growth is typically calculated with steady state assumptions, where the condensation sink is the only loss term for the vapours. Additionally, the growth to CCN sizes is represented with the condensation of extremely low-volatile vapours and gas-particle partitioning of semi-volatile vapours. Here, we use a novel automatic method to determine growth rates (GR) from below 10&#8201;nm to hundreds of nanometres from a 20-years long particle size distribution data set in Boreal forest. With this method, we are able to detect growth rates also at other times than immediately after a NPF event. We show that the GR increases with an increasing oxidation rate of monoterpenes, which is closely coupled with the ambient temperature. Based on our analysis, the oxidation reactions of monoterpenes with ozone, hydroxyl radical and nitrate radical all are capable of producing vapours that contribute to the particle growth in the studied size ranges. We find that GR increases with particle diameter, resulting in up to three-fold GRs for particles with dP ~&#8201;100&#8201;nm in comparison to those with dP ~&#8201;10&#8201;nm. We use a single particle model to show that this increase in GR can be explained with aerosol-phase reactions, in which semi-volatile vapours form non-volatile dimers. Finally, our analysis reveals that the GR of particles with dP&#8201;<&#8201;100&#8201;nm is not limited by the condensation sink, even though the GR of larger particles is. Our findings suggest that in the Boreal continental environment, the formation of CCN from NPF or sub-100&#8201;nm emissions is more effective than previously thought, and that the formation of CCN is not as strongly self-limiting process as the previous estimates have suggested.

show abstract

Variability of air ion concentrations in urban Paris

Cited by 21 publications

References 86 publications

Differentiating between particle formation and growth events in an urban environment

Differentiating between particle formation and growth events in an urban environment

Comprehensive analysis of particle growth rates from nucleation mode to cloud condensation nuclei in boreal forest

Comprehensive analysis of particle growth rates from nucleation mode to cloud condensation nuclei in Boreal forest

Contact Info

Product

Resources

About