Observation of ions and particles near busy roads using a neutral cluster and air ion spectrometer (NAIS)

Jayaratne, E.R.; Ling, Xuan; Morawska, Lidia

doi:10.1016/j.atmosenv.2013.11.045

Cited by 21 publications

(16 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The simultaneous decrease in small ion concentrations and increase in large ion concentrations and particle number (Fig. 2e-g) suggests that part of the small ion population was lost by attachment to aerosol particles as observed in previous studies (Hirsikko et al, 2007b;Jayaratne et al, 2014). The concentrations of positive small ions in the mornings of workdays (07:00) were about 26 % lower in comparison to the mornings of weekends (07:00) indicating that this fraction may have been lost by coagulation to pre-existing aerosol particles.…”

Section: Diurnal Cycles and Number Size Distributions Of Ionssupporting

confidence: 53%

“…Nevertheless, the number of studies focusing on the behaviour of air ions and particularly its association to NPF in urban areas around the world is still somewhat limited (e.g. Tiitta et al, 2007;Hirsikko et al, 2007b;Retalis et al, 2009;Tammet et al, 2014;Gagné et al, 2012;Herrmann et al, 2014;Backman et al, 2012;Crilley et al, 2014;Jayaratne et al, 2010Jayaratne et al, , 2014Ling et al, 2013;Ling et al, 2010;Siingh et al, 2013;Lee et al, 2012;Iida et al, 2006Iida et al, , 2008Pikridas et al, 2015), and actually only some of them measured ion size distributions. The main aim of this study was to determine the frequency and seasonal variations of NPF events in a megacity based on ion number size distribution measurements.…”

Section: N Dos Santos Et Al: Variability Of Air Ion Concentratiomentioning

confidence: 99%

See 1 more Smart Citation

Variability of air ion concentrations in urban Paris

et al. 2015

View full text Add to dashboard Cite

Abstract. Air ion concentrations influence new particle formation and consequently the global aerosol as potential cloud condensation nuclei. We aimed to evaluate air ion concentrations and characteristics of new particle formation events (NPF) in the megacity of Paris, France, within the MEGAPOLI (Megacities: Emissions, urban, regional and Global Atmospheric Pollution and climate effects, and Integrated tools for assessment and mitigation) project. We measured air ion number size distributions (0.8-42 nm) with an air ion spectrometer and fine particle number concentrations (> 6 nm) with a twin differential mobility particle sizer in an urban site of Paris between 26 June 2009 and 4 October 2010. Air ions were size classified as small (0.8-2 nm), intermediate (2-7 nm), and large (7-20 nm). The median concentrations of small and large ions were 670 and 680 cm −3 , respectively, (sum of positive and negative polarities), whereas the median concentration of intermediate ions was only 20 cm −3 , as these ions were mostly present during new particle formation bursts, i.e. when gas-to-particle conversion produced fresh aerosol particles from gas phase precursors. During peaks in traffic-related particle number, the concentrations of small and intermediate ions decreased, whereas the concentrations of large ions increased. Seasonal variations affected the ion population differently, with respect to their size and polarity. NPF was observed in 13 % of the days, being most frequent in spring and late summer (April, May, July, and August). The results also suggest that NPF was favoured on the weekends in comparison to workdays, likely due to the lower levels of condensation sinks in the mornings of weekends (CS weekdays 09:00: 18 × 10 −3 s −1 ; CS weekend 09:00: 8 × 10 −3 s −1 ). The median growth rates (GR) of ions during the NPF events varied between 3 and 7 nm h −1 , increasing with the ion size and being higher on workdays than on weekends for intermediate and large ions. The median GR of small ions on the other hand were rather similar on workdays and weekends. In general, NPF bursts changed the diurnal cycle of particle number as well as intermediate and large ions by causing an extra peak between 09:00 and 14:00. On average, during the NPF bursts the concentrations of intermediate ions were 8.5-10 times higher than on NPF non-event days, depending on the polarity, and the concentrations of large ions and particles were 1.5-1.8 and 1.2 times higher, respectively. Because the median concentrations of intermediate ions were considerably higher on NPF event days in comparison to NPF nonevent days, the results indicate that intermediate ion concentrations could be used as an indication for NPF in Paris. The results suggest that NPF was a source of ions and aerosol particles in Paris and therefore contributed to both air quality degradation and climatic effects, especially in the spring and summer.

show abstract

Section: Diurnal Cycles and Number Size Distributions Of Ionssupporting

confidence: 53%

Section: N Dos Santos Et Al: Variability Of Air Ion Concentratiomentioning

confidence: 99%

Variability of air ion concentrations in urban Paris

et al. 2015

View full text Add to dashboard Cite

show abstract

“…More details of all these monitoring sites may be found in Ling et al (2010). Some of the results from one of the two PSC OHVPL sites and one of the three freeway sites have been reported before in Jayaratne et al (2011) and Jayaratne et al (2014), respectively. The analysis in this paper extends these results to several other sites so that the results are more representative of each type of site and provides much better comparison.…”

Section: Site Description and Measurement Techniquesmentioning

confidence: 84%

Comparison of charged nanoparticle concentrations near busy roads and overhead high-voltage power lines

Jayaratne

Ling

Morawska

2015

Science of The Total Environment

Self Cite

View full text Add to dashboard Cite

“…These two studies are described in two earlier publications (Ling et al, 2013;Jayaratne et al, 2014).…”

Section: Methodsmentioning

confidence: 99%

“…We have included the clean rural site and the polluted roadside site. The latter point comprises measurements over a 30 min period near the curb of a busy motorway and the values are derived from Jayaratne et al (2014). The pyrotechnic event between 19:00 and 19:25 on 29 September (Fig.…”

Section: General Trends Of Cic Versus Pncmentioning

confidence: 99%

Suppression of Cluster Ions during Rapidly Increasing Particle Number Concentration Events in the Environment

Jayaratne

Ling

Morawska

2015

Aerosol Air Qual. Res.

View full text Add to dashboard Cite

We show that the cluster ion concentration (CIC) in the atmosphere is significantly suppressed during events that involve rapid increases in particle number concentration (PNC). Using a neutral cluster and air ion spectrometer, we investigated changes in CIC during three types of particle enhancement processes -new particle formation, a bushfire episode and an intense pyrotechnic display. In all three cases, the total CIC decreased with increasing PNC, with the rate of decrease being greater for negative CIC than positive. We attribute this to the greater mobility, and hence the higher attachment coefficient, of negative ions over positive ions in the air. During the pyrotechnic display, the rapid increase in PNC was sufficient to reduce the CIC of both polarities to zero. At the height of the display, the negative CIC stayed at zero for a full 10 min. Although the PNCs were not significantly different, the CIC during new particle formation did not decrease as much as during the bushfire episode and the pyrotechnic display. We suggest that the rate of increase of PNC, together with particle size, also play important roles in suppressing CIC in the atmosphere.

show abstract

Observation of ions and particles near busy roads using a neutral cluster and air ion spectrometer (NAIS)

Cited by 21 publications

References 18 publications

Variability of air ion concentrations in urban Paris

Variability of air ion concentrations in urban Paris

Comparison of charged nanoparticle concentrations near busy roads and overhead high-voltage power lines

Suppression of Cluster Ions during Rapidly Increasing Particle Number Concentration Events in the Environment

Contact Info

Product

Resources

About