We developed a new method to measure how particles absorb light as they change in size, which is critical for understanding their climate impact. Our approach uses a sensitive instrument that measures light absorption directly from particles in real time. By pairing this with a device that sorts particles by size, we achieved accurate size-resolved measurements. Our findings closely match theoretical models, offering a promising tool for future research into how particles influence climate.

This study examines new particle formation (NPF) in the Bolivian Andes at Chacaltaya mountain (CHC) and the urban El Alto–La Paz area (EAC). Days are clustered into four categories based on NPF intensity. Differences in particle size, precursor gases, and pollution levels are found. High NPF intensities increased Aitken mode particle concentrations at both sites, while volcanic influence selectively diminished NPF intensity at CHC but not EAC. This study highlights NPF dynamics in the Andes.

We assessed the performance of four cascade impactors for collecting and analyzing organic markers in airborne ultrafine particles (UFPs) under lab and field conditions. The cutoff was influenced by the impactor design and aerosol mixture. Two key factors caused variations in mass concentrations: the evaporation of semi-volatile compounds and the "bounce-off" of larger particles and fragments. Our findings reveal the challenges of analyzing organic marker mass concentrations in airborne UFPs.

Aersols are important in many parts of industry and research. To learn more about aerosols, especially when they contain nanoparticles, the Centrifugal Differential Mobility Anlayser (CDMA) presented here allows us to measure the mobility-equivalent diameter and the Stokes equivalent diameter at the same time. The result is a 2D property distribution that provides deeper information about the entire particle collective than the isolated measurement principles.