Impact of aerosol–radiation interaction on new particle formation

Abstract

Abstract. New particle formation (NPF) is thought to contribute half of the global cloud condensation nuclei. A better understanding of the NPF at different altitudes can help assess the impact of NPF on cloud formation and corresponding physical properties. However, NPF is not sufficiently understood in the upper mixing layer because previous studies mainly focused on ground-level measurements. In this study, the developments of aerosol size distribution at different altitudes are characterized based on the field measurement conducted in January 2019 in Beijing, China. We find that the partition of nucleation-mode particles in the upper mixing layer is larger than that at the ground, which implies that the nucleation processing is more likely to happen in the upper mixing layer than that at the ground. Results of the radiative transfer model show that the photolysis rates of the nitrogen dioxide and ozone increase with altitude within the mixing layer, which leads to a higher concentration of sulfuric acid in the upper mixing layer than that at the ground. Therefore, the nucleation processing in the upper mixing layer should be stronger than that at the ground, which is consistent with our measurement results. Our study emphasizes the influence of aerosol–radiation interaction on the NPF. These results have the potential to improve our understanding of the source of cloud condensation nuclei on a global scale due to the impacts of aerosol–radiation interaction.

Particle Number Size Distribution of Wintertime Alpine Aerosols and Their Activation as Cloud Condensation Nuclei in the Guanzhong Plain, Northwest China

“…In P2 episode, however, the effects of SO 2 on number concentration and GMD were different, suggesting that SO 2 played an important role in the formation of particles to increase the number concentration rather than their diameter growth. This was consistent with the study of formation of granular seeds after SO 2 was converted into sulfuric acid (Okuljar et al., 2021; Williamson et al., 2021; Zhao et al., 2021). However, compared to the positive correlation between SO 2 and particle number concentration, the concentration of NH 3 was negatively correlated with number concentration, which was related to the gradual increase of temperature and the decrease of RH in this episode.…”

“…The applicability of lognormal particle size distributions in describing the properties of aerosol size distributions has been discussed in several papers (Koponen, 2003; Monteiro dos Santos et al., 2021; Ueda et al., 2016; Q.‐R. Yu et al., 2019; Zhao et al., 2021). All the PNSD could be fitted using unimodal or bimodal lognormal modes: nucleation modes (<30 nm), Aitken mode (30–100 nm), and up to an accumulation mode (>100 nm) (Monteiro dos Santos et al., 2021).…”

“…Subsequently, the freshly formed clusters adsorb more gaseous molecules increasing their diameter, and gradually transit to nucleation mode and Aitken mode. Some researchers found that the number of aerosols from NPF can contribute to about half of the global CCN (Andreae et al., 2022; Cai et al., 2021; Franco et al., 2022; Zhao et al., 2021). According to the Köhler theory, the larger the particle is, the easier it is to be activated (Petters & Kreidenweis, 2007).…”

Vigorous New Particle Formation Above Polluted Boundary Layer in the North China Plain

“…Given the vertically varying cloud distribution and the vital role of NPF in the CCN budget, it is of great importance to understand the vertical profile of NPF. As revealed in previous studies, the NPF can be altitude-dependent (Boulon et al, 2011;Lai et al, 2022;Lampilahti et al, 2021;Quan et al, 2017;Zhao et al, 2021). Several aircraft measurement campaigns have been conducted to investigate the vertical distributions of NPF and reported large numbers of small particles at high altitude (Andreae et al, 2018;Krejci et al, 2005;Platis et al, 2016;Takegawa et al, 2020;Wang et al, 2016;Weigel et al, 2011;Williamson et al, 2019;Zhao et al, 2020).…”

“…Wang et al (2016) and Zhao et al (2020) showed that high concentrations of small particles formed by organic NPF in the lower free troposphere are transported into the boundary layer in the Amazon. Zhao et al (2021) demonstrated a preference to observe higher nucleation-mode particle concentrations in the upper mixing layer than at the ground, attributable to the vertical profile of ultraviolet radiation based on measurement at the tower-based platform with a maximum height of 350 m. Using tethered airship, Qi et al (2019) reported evidence of intensive NPF events above the planetary boundary layer (PBL) of megacities due to high oxidizing capacity, enough condensable vapors, and low condensation sink above the PBL. Boulon et al (2011) showed that NPF occurred more frequently at the higher elevation due to lower condensation sinks.…”