Toward direct measurement of atmospheric nucleation.

Atmospheric 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.

Relationship between different size classes of particulate matter and meteorology in three European cities.

Evidence on the correlation between particle mass and (ultrafine) particle number concentrations is limited. Winter- and spring-time measurements of urban background air pollution were performed in Amsterdam (The Netherlands), Erfurt (Germany) and Helsinki (Finland), within the framework of the EU funded ULTRA study. Daily average concentrations of ambient particulate matter with a 50% cut off of 2.

Resuspended dust episodes as an urban air-quality problem in subarctic regions.

Objectives: This paper describes the resuspension of road dust in an urban subarctic environment and focuses especially on the effect of wind speed on the formation of resuspended dust episodes.

Methods: The study was conducted in Kuopio, Finland, in the spring of 1995. There were 36 daily measurements of mass concentrations of fine particulate matter (PM2.