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

Abstract

<p><strong>Abstract.</strong> 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 (D<sub>pgmax</sub>) 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 D<sub>pgmax</sub> < 20 nm was observed in all of the events occurring in December, in approximately half of the NPF events occurring in April and only 2/27 of the NPF events occurring in June–August. New particles observed in the latter NPF events were too small to be activated as cloud condensation nuclei. Apparent new particle growth with D<sub>pgmax</sub> ≤ 50 nm was observed in the remaining NPF events. The 11/27 NPF events with D<sub>pgmax</sub> exceeded 75 nm were thereby analyzed in-depth. They are clearly three particle growth pattern classifications: one-stage growth, which is characterized by a continuous increase in D<sub>pgmax</sub> ≥ 80 nm (4/11 NPF events), and two-stage growth-A and growth-B, which are characterized by either no apparent growth (two-stage growth-A) or a shrinkage of particles (two-stage growth-B) in the middle 2–4 hours of the growth period (7/11 NPF events). Combining the observations of gaseous pollutants and the measured (or modeled) concentrations of particulate chemical species, the three growth patterns were discussed in terms of the spatial heterogeneity of NPF, the formation of secondary aerosols and the evaporation of semi-volatile particulates. Secondary organic species and NH<sub>4</sub>NO<sub>3</sub> were argued to be two major contributors to the growth in new particles, but NH<sub>4</sub>NO<sub>3</sub> likely contributed to growth only in the late afternoon and/or at nighttime.</p>

Increased new particle yields with largely decreased probability of survival to CCN size at the summit of Mt. Tai under reduced SO<sub>2</sub> emissions

“…6). The fitted equation was highly consistent with those derived for urban and marine atmospheres (Man et al, 2015;Zhu et al, 2017Zhu et al, , 2019Ma et al, 2020). The strong linear relationship between the apparent FR and NMINP suggested that H 2 SO 4 vapor was sufficient for nucleation, and the NPF intensity was very likely determined by the abundance of organic vapors available for participating in nucleation.…”

“…Relationship between the FR and NMINP in 106 cases of NPF events at Mt. Tai in this study and in urban and marine atmospheres in previous studies (Man et al, 2015;Zhu et al, 2017Zhu et al, , 2019Ma et al, 2020). The half-solid markers can be fitted linearly in previous studies.…”

Increased new particle yields with largely decreased probability of survival to CCN size at the summit of Mt. Tai under reduced SO<sub>2</sub> emissions

“…The fitted equation was highly consistent with those derived for urban and marine atmospheres (Man et al, 2015;Zhu et al, , 2019Ma et al, 2020). The strong linear relationship between the FR and NMINP suggested that H2SO4 vapor was sufficient for nucleation, and the NPF intensity was very likely determined by the abundance of organic vapors available for participating in nucleation.…”

Investigation of Particle Number Concentrations and New Particle Formation With Largely Reduced Air Pollutant Emissions at a Coastal Semi‐Urban Site in Northern China

“…Shen et al, 2011). In contrast, the averages nearly doubled (2.9-3.3 × 10 4 cm −3 ) in urban atmospheres over semi-arid and arid urban areas of China (e.g., Beijing and Urumchi), possibly because of reduced wet deposition and a higher occurrence frequency of NPF events (L. Ma et al, 2021;Peng et al, 2014;Wu et al, 2008). The t-PNC values in the nonheating season (April to October) and heating season (November to March in the following year) were also compared separately.…”

“…On the other hand, the reduced amount of sulfuric acid condensed on newly formed particles may also reduce the aerosol acidity, subsequently affecting the acid-enhanced uptake of semi-volatile organic species (Ding et al, 2011;Stangl et al, 2019). Ammonium nitrate has also been reported to promote the second-stage growth of new particles at nighttime (X. H. Liu et al, 2014;L. Ma et al, 2021;Man et al, 2015;Zhu et al, 2014).…”