Dust particles suspended in the atmosphere, known as aerosols, affect the earth's climate in two ways. They absorb and scatter solar radiation, and they affect the physical properties of clouds. Aerosols are thought to have a net cooling effect and thus they may mask the potential warming effects of anthropogenic increases in greenhouse gases. Despite their importance, aerosol-climate interactions represent a large source of uncertainty in understanding the climate system. A key reason for this uncertainty is that aerosols demonstrate high variability, both spatially and temporally, yet the extent of their variability has not been fully investigated. Constraints associated with conventional approaches to measuring total column aerosol-including the requirements for clear skies and costly equipment-have contributed to a paucity of aerosol data. Although the majority of anthropogenic aerosols (i.e. pollution) are emitted in the Northern Hemisphere, there are very few reliable long-term records of total column aerosol in the northern half of the globe. This research will employ a radiation-based model, together with satellite and climate data, to evaluate seasonal, interannual, and spatial variability of aerosols in Western Europe, regardless of cloud cover. A key product will be a more complete documentation of the amount and variability of aerosols than is currently available. Time series and spatial analyses will also be used to investigate the degree to which pollution may be augmenting the background aerosol load, and will permit detection of possible volcanic influences on the aerosol signal.
The results of this research will help explain climate change and variability in Western Europe reported by other investigators, and will also help elucidate the relative roles of aerosols and greenhouse gases in the climate system. This will permit improvements in how aerosols are represented in regional and global climate models. This research will therefore enhance our understanding of climate and climate change, and will help policy makers prepare informed climate change policies.
