English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The concentrations of neutral and charged sub-3nm clusters and theirconnection to new particle formation (NPF) were investigated during thePEGASOS campaign (7 June–9 July 2012) at the San Pietro Capofiumemeasurement station in the Po Valley, Italy. Continuous high concentrationsof sub-3nm clusters were detected during the measurement period, althoughthe condensation sink was relatively high (median value 1.1 × 10−2 s−1). The median cluster concentrations were 2140and 7980 cm−3 in the size bins of 1.5–1.8 and 1.8–3 nm,and the majority of them were electrically neutral. NPF events wereobserved during the measurement period frequently, on 86 % of the days.The median growth rates of clusters during the events were 4.3,6.0 and 7.2 nm h−1 in the size ranges of 1.5–3,3–7 and 7–20 nm. The median formation rate of 1.6 nmclusters was high, 45 cm−3 s−1, and it exceeded the medianformation rate of 2 nm clusters by 1 order of magnitude. The ion-inducednucleation fraction was low; the median values were 0.7 % at 1.6 nm and3.0 % at 2 nm. On NPF event days the neutral cluster concentration had amaximum around 09:00 (local winter time), which was absent on a non-eventday. The increase in the cluster concentrations in the morning coincidedwith the increase in the boundary layer height. At the same time radiation,temperature and SO2 concentration increased, and RH and condensationsink decreased. The concentrations of neutral and charged clusters wereobserved to have a positive correlation with sulfuric acid proxy, indicatingthe significance of sulfuric acid for the cluster formation in San PietroCapofiume. The condensation sink had a negative correlation with theconcentration of charged clusters but no clear relation to the neutralcluster concentration. This finding, together with back-trajectory analysis,suggests that the precursor vapors of the clusters and background aerosolparticles, acting as their sink, have possibly originated from the samesources, including e.g., power plants and industrial areas in the Po Valley

High concentrations of sub-3nm clusters and frequent new particle formation observed in the Po Valley, Italy, during the PEGASOS 2012 campaign