Measurement of the nucleation of atmospheric aerosol particles.
The formation of new atmospheric aerosol particles and their subsequent growth have been observed frequently at various locations all over the world. The atmospheric nucleation rate (or formation rate) and growth rate (GR) are key parameters to characterize the phenomenon. Recent progress in measurement techniques enables us to measure atmospheric nucleation at the size (mobility diameter) of 1.5 (±0.4) nm. The detection limit has decreased from 3 to 1 nm within the past 10 years. In this protocol, we describe the procedures for identifying new-particle-formation (NPF) events, and for determining the nucleation, formation and growth rates during such events under atmospheric conditions. We describe the present instrumentation, best practices and other tools used to investigate atmospheric nucleation and NPF at a certain mobility diameter (1.5, 2.0 or 3.0 nm). The key instruments comprise devices capable of measuring the number concentration of the formed nanoparticles and their size, such as a suite of modern condensation particle counters (CPCs) and air ion spectrometers, and devices for characterizing the pre-existing particle number concentration distribution, such as a differential mobility particle sizer (DMPS). We also discuss the reliability of the methods used and requirements for proper measurements and data analysis. The time scale for realizing this procedure is 1 year.
Department of Physics, University of Helsinki, Helsinki, Finland. markku.kulmala@helsinki.fi
Markku
M
Kulmala
Tuukka
T
Petäjä
Tuomo
T
Nieminen
Mikko
M
Sipilä
Hanna E
HE
Manninen
Katrianne
K
Lehtipalo
Miikka
M
Dal Maso
Pasi P
PP
Aalto
Heikki
H
Junninen
Pauli
P
Paasonen
Ilona
I
Riipinen
Kari E J
KE
Lehtinen
Ari
A
Laaksonen
Veli-Matti
VM
Kerminen
D000336:Aerosols / Q000032:analysis*; D000393:Air Pollutants / Q000032:analysis*; D001272:Atmosphere / Q000032:analysis*; D002623:Chemistry Techniques, Analytical / Q000295:instrumentation / Q000379:methods*; D004784:Environmental Monitoring / Q000295:instrumentation / Q000379:methods*; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis*
D000336:Aerosols; D000393:Air Pollutants; D052638:Particulate Matter