Observation of regional new particle formation in the urban atmosphere
Open Access
- 1 January 2008
- journal article
- Published by Stockholm University Press in Tellus B: Chemical and Physical Meteorology
- Vol. 60 (4), 509-521
- https://doi.org/10.1111/j.1600-0889.2008.00365.x
Abstract
Long-term measurements of fine particle number-size distributions were carried out over 9.5 yr (May 1997–December 2006), in the urban background atmosphere of Helsinki. The total number of days was 3528 with about 91.9% valid data. A new particle formation event (NPF) is defined if a distinct nucleation mode of aerosol particles is observed below 25 nm for several hours, and it shows a growth pattern. We observed 185 NPF events, 111 d were clear non-events and most of the days (around 83.5%) were undefined. The observed events were regional because they were observed at Hyytiälä (250 km north of Helsinki). The events occurred most frequently during spring and autumn. The observed formation rate was maximum during the spring and summer (monthly median 2.87 cm-3 s-1) and the modal growth rate was maximum during late summer and Autumn (monthly median 6.55 nm h-1). The events were observed around noon, and the growth pattern often continued on the following day. The observation of weak NPF events was hindered due to pre-existing particles from both local sources. It is clear that regional NPF events have a clear influence on the dynamic behaviour of aerosol particles in the urban atmosphere. DOI: 10.1111/j.1600-0889.2008.00365.xKeywords
This publication has 19 references indexed in Scilit:
- Characteristics of regional nucleation events in urban East St. LouisAtmospheric Environment, 2007
- Indoor and outdoor particle size characterization at a family house in Espoo–FinlandAtmospheric Environment, 2005
- Global indirect aerosol effects: a reviewAtmospheric Chemistry and Physics, 2005
- Atmospheric particle formation events at Värriö measurement station in Finnish Lapland 1998-2002Atmospheric Chemistry and Physics, 2004
- A model for particle formation and growth in the atmosphere with molecular resolution in sizeAtmospheric Chemistry and Physics, 2003
- Bursts of Aitken mode and ultrafine particles observed at the top of continental boundary layer cloudsJournal of Aerosol Science, 2001
- On the photochemical production of new particles in the coastal boundary layerGeophysical Research Letters, 1999
- The potential for atmospheric mixing processes to enhance the binary nucleation ratePublished by American Geophysical Union (AGU) ,1998
- Binary Homogeneous Nucleation: Temperature and Relative Humidity Fluctuations, Nonlinearity, and Aspects of New Particle Production in the AtmosphereJournal of Applied Meteorology and Climatology, 1994
- The physical characteristics of sulfur aerosolsAtmospheric Environment (1967), 1978