Measurements of Ice Nucleating Particles in Beijing, China

Abstract

Heterogeneous ice nucleating particle (INP) concentrations are reported for a site on the eastern margin of Beijing, China, during the period 4 May to 4 June 2018. INP concentrations were measured continuously at −20, −25, and −30 °C in a repeating cycle by a newly developed, automated continuous flow diffusion chamber, and reached concentrations as high as 2800 sL−1 during dust-impacted periods. Study average concentrations were 70 ± 70, 230 ± 290, and 430 ± 500 sL−1 at −20, −25, and −30 °C. There was no clear relationship between pollution periods, identified based on fine-mode particle concentration increases, and INP concentrations or characteristics. Other anthropogenic emissions, such as non-combustion industrial or agricultural activities play an unresolved role.