Author(s)

M. Pohjola, A. Kousa, P. Aarnio, T. Koskentalo, J. Kukkonen, J. Harkonen & A. Karppinen

Abstract

Meteorological interpretation of measured urban PM, _ and PM,_ conce £*^ AU Helsinki Metropolitan Area urban PM, _ and PM,_ concentrations in the £*^ AU M. Pohjola^, A. Kousa\ P. Aarnio\ T. Koskentalo\ J. KukkonenJ. Harkonen^ & A. Karppinen^ ^Helsinki Metropolitan Area Council, Finland ^Finnish Meteorological Institute, Air Quality Research, Finland Abstract We have analysed PM]5 and PMio concentrations, determined at the urban air quality measurement network in the Helsinki Metropolitan Area during 1997 - 1998. The data includes PIVbs concentrations measured at two locations (urban traffic and urban background sites), and PM,o concentrations measured at five locations (two urban and one suburban traffic, urban background and regional background sites). The seasonal and diurnal variation of PM%5 and PMio concentrations at the measurement sites in 1997 - 1998 are interpreted in terms of relevant meteorological variables. 1 Introduct

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