Annual and interannual variation in boreal forest aerosol particle number and volume concentration and their connection to particle formation |
| |
| Authors: | MIIKKA DAL MASO ANTTI HYVÄRINEN MIKA KOMPPULA PETER TUNVED VELI-MATTI KERMINEN HEIKKI LIHAVAINEN YRJÖ VIISANEN HANS-CHRISTEN HANSSON MARKKU KULMALA |
| |
| Institution: | Department of Physical Sciences, University of Helsinki, P.O. Box 64, 00014 Helsinki, Finland;;Finnish Meteorological Institute, P.O. Box 503, 00101 Helsinki, Finland;;Department of Applied Environmental Science, Stockholm University, SE-10691 Stockholm, Sweden;;ICG-II, Forschugszentrum Jülich, 52425 Jülich, Germany |
| |
| Abstract: | We investigated size-resolved submicrometre aerosol particle number and volume concentration time series as well as aerosol dynamic parameters derived from Differential Mobility Particle Sizer (DMPS) measurements at five background stations in the Nordic boreal forest area. The stations in question were Aspvreten, Hyytiälä and Utö in southern Finland and Sweden, and Värriö and Pallas in the Finnish Lapland. The objective of our investigation was to identify and quantify annual and interannual variation observable in the time series. We found that the total number and mass concentrations were much lower at the Lapland stations than at the southern stations and that the total particle number was strongly correlated to particle formation event frequency. The annual total number concentration followed the annual distribution of particle formation events at the southern stations but much less clearly at the Lapland stations. The volume concentration was highest during summer, in line with higher condensation growth rates; this is in line with the assumption that a large part of the particle volume is produced by oxidized plant emissions. The decrease of sulphate emissions in Europe was not visible in our data set. Aerosol dynamic parameters such as condensation sink, condensation sink diameter and the power law exponent linking coagulation losses and condensation sink are presented to characterize the submicron Nordic background aerosol. |
| |
| Keywords: | |
|
|
