EARLINET: A European Aerosol Research Lidar Network to establish an aerosol climatology

The European Aerosol Research Lidar Network (EARLINET) has been established in 2000 to derive a comprehensive and statistically relevant quantitative data base of the aerosol vertical distribution over Europe. For this purpose, regular lidar measurements have been performed at 22 locations in 13 European countries. Most of the measurements have been taken on a fixed schedule at preselected times and days to avoid a fair weather bias in the statistics. Additional measurements have been performed to investigate special topics like Saharan dust outbreaks, temporal cycles, the modification of aerosol on its way through Europe or long range transport of aerosol to Europe. All instruments have been quality controlled in extensive intercomparison experiments. The algorithms used to derive aerosol backscatter and extinction have been tested separately using synthetic lidar data. The EARLINET quality assurance is presented in detail in MPI report 337. This report gives the main results of the EARLINET project which have been achieved up to spring 2003. Most relevant topics are - data base on aerosol vertical profiles and backtrajectories - temporal cycles of the aerosol distribution - observation of special events, e.g. Saharan dust and forest fires - impact of the aerosol vertical distribution on satellite retrievals - aerosol modification during transport over Europe - influence of orography on aerosol vertical transport - stratospheric aerosol - differences between rural and urban aerosol - effect of aerosol on UV-B radiation - statistical analysis of the aerosol vertical profiles - lidar ratio statistical analysis - long range transport of aerosol to Europe - algorithms to derive aerosol microphysics from lidar dat