Different characteristics of new particle formation between urban and deciduous forest sites in Northern Japan during the summers of 2010–2011

Abstract

Abstract. To investigate new particle formation (NPF) events in urban and forest environments, number size distributions of ultrafine particles were measured at an urban site and a deciduous forest site in Sapporo, Northern Japan, during the summers of 2011 and 2010, respectively. The burst of nucleation mode particles at the urban site typically started in the morning (07:00-11:30 local time, LT) with simultaneous increases in SO 2 and O 3 concentrations and the UV index under clear (sunny) weather conditions. The growth rates of nucleated particles at the urban site ranged from 5.0 to 7.8 nm h −1 with an average of 6.3 ± 1

Hygroscopic properties of newly formed ultrafine particles at an urban site surrounded by deciduous forest (Sapporo, northern Japan) during the summer of 2011

“…An NPF event was defined as a sharp increase in the N nuc /number concentration of ultrafine particles (N UFP : 7-100 nm) ratios of > 0.5 with elevated N UFP (refer to Fig. 3 in Jung et al, 2013). Increases in the number concentrations of humidified particles at a dry D p of 20 nm were observed during the NPF event periods (Fig.…”

“…Agarwal et al (2010) reported that most of dicarboxylic acids, α-dicarbonyls, levoglucosan, water-soluble organic carbon (WSOC), and inorganic ions (i.e., SO 2− 4 , NH + 4 , and K + ) were abundant in fine particles (PM 1.1 ) collected at the Sapporo urban site during the summer of 2005. Using particle size distributions during the summer of 2011, Jung et al (2013) showed that the burst of nucleation mode particles typically started in the morning (07:00-11:30 LT) at the same urban site, with simultaneous increases in concentrations of SO 2 , O 3 , and the UV index under clear weather conditions.…”

“…The Mode D p of freshly formed nucleation mode particles was obtained from particle number size distributions averaged over the 1 h period from the beginning of the burst of nucleation mode particles. Similarly, the Mode D p of nucleated particles that had grown to Aitken mode sizes, hereafter referred to as the Aitken mode particles, was obtained from particle number size distribution averaged over the 1 h period before the end of a linear growth of the Mode D p of freshly formed nucleation mode particles (Jung et al, 2013). The Mode D p of freshly formed nucleation mode particles ranged from 12 to 24 nm, with an average of 16 ± 3 nm, whereas the Mode D p of particles after particle growth ranged from 38 to 48 nm, with an average of 44 ± 5 nm ( Table 1).…”

“…However, the hygroscopic properties of freshly nucleated particles have rarely been studied, especially in an urban area adjacent to a deciduous forest. Jung et al (2013) measured particle number size distributions at an urban site in Sapporo, northern Japan, using a scanning mobility particle sizer (SMPS) during the summer of 2011, and discussed the factors controlling the burst of nucleation mode particles and the subsequent growth. As the burst of nucleation mode particles is mainly caused by the growth of nucleated clusters (< 1 nm) into a detectable size (> 3 nm), we define particles generated by the burst of nucleation mode particles during the NPF event as freshly formed nucleation mode particles.…”

Contribution from biogenic organic compounds to particle growth during the 2010 BEACHON-ROCS campaign in a Colorado temperate needleleaf forest

“…It provides an opportunity to study biogenic SOA formation at a rural-urban interface . Various studies have indicated that biogenic SOA formation in forest environments can be enhanced by the inflow of anthropogenic pollutants (Boy et al, 2008;Hoyle et al, 2011;Jung et al, 2013). The modeling tool used in this study is the chemical-transport column model SOSAA (model to Simulate Organic vapors, Sulfuric Acid and Aerosols; Zhou et al, 2014).…”