Toward Direct Measurement of Atmospheric Nucleation
2007; American Association for the Advancement of Science; Volume: 318; Issue: 5847 Linguagem: Inglês
10.1126/science.1144124
ISSN1095-9203
AutoresMarkku Kulmala, Ilona Riipinen, Mikko Sipilä, Hanna E. Manninen, Tuukka Petäjä, Heikki Junninen, Miikka Dal Maso, Genrik Mordas, A. Mirme, Marko Vana, Anne Hirsikko, Lauri Laakso, Roy M. Harrison, Ian Hanson, Carl Leung, K. E. J. Lehtinen, Veli‐Matti Kerminen,
Tópico(s)Atmospheric Ozone and Climate
ResumoAtmospheric aerosol formation is known to occur almost all over the world, and the importance of these particles to climate and air quality has been recognized. Although almost all of the processes driving aerosol formation take place below a particle diameter of 3 nanometers, observations cover only larger particles. We introduce an instrumental setup to measure atmospheric concentrations of both neutral and charged nanometer-sized clusters. By applying the instruments in the field, we come to three important conclusions: (i) A pool of numerous neutral clusters in the sub–3 nanometer size range is continuously present; (ii) the processes initiating atmospheric aerosol formation start from particle sizes of ∼1.5 nanometers; and (iii) neutral nucleation dominates over the ion-induced mechanism, at least in boreal forest conditions.
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