Suspended particulate matter in the atmosphere, commonly known as aerosol by the technical and scientific community, plays a role in climate change, air quality/human health, ozone depletion and the long-range transport and deposition of toxics and nutrients. Aerosols have many sources ranging from sea spray and mineral dust that are mechanically generated by wind at the Earth’s surface to sulphates, nitrates and organics produced primarily by chemical reaction of gases in the atmosphere producing non-volatile products that condense to form particles. In addition, semi-volatile substances such as certain herbicides and pesticides can simply condense on existing particles. Aerosols range in size from molecular clusters a few nm in diameter to dust and sea salt, which can be as large as tens of micrometers. The dynamics of aerosol production, transformation and removal that govern size distribution and composition are affected not only by clear air processes but also by interaction with clouds and precipitation. The complexity of aerosol processes in our environment is so great that it leads to large uncertainties in our quantitative understanding of their role in many of the major environmental issues listed above. This report is based on a workshop on a European Network of Networks (ENAN) in Emmetten, Switzerland on 28-29 April, 2009. It was a joint initiative of the Global Earth Observation and Monitoring (GEOmon) project of the European Community’s Sixth Research Framework Programme (FP6) and the Scientific Advisory Group for Aerosols of the Global Atmosphere Watch (GAW) Programme of the World Meteorological Organization (WMO).
Collection(s) and Series: GAW Report- No. 207
Format: Digital (Free)