Eyjafjallaj?kull volcano ash plume detection in the frame of the new constituting lidar network Leonet

Eyjafjallajkull volcano eruptions of ash plumes starting on April 2010 paralyzed completely air traffic in Europe for several days. During the crisis, Leosphere collected 24/7 real time measurements of the backscatter profiles, taken by ALS polarizations lidars spread from Denmark to South of France in order to provide quick looks of the sky at regular intervals for different met agencies and for the Volcanic Ash Advisory Centres (VAAC) coordinated by UK MetOffice. Moreover, Meteo France supported by other institutions such as CNRS (Centre National de la Recherche Scientifique), CEA (Commissariat ? l'Energie Atomique), CNES (Centre National d'?tudes Spatiales) and Leosphere performed several test flights over France and North Atlantic with an airborne Lidar. These unique data allowed detection and identification of ash plume and provided a guidance regarding the decision-making chain. The ash mass concentration and its calculation were also discussed. ? 2010 Copyright SPIE - The International Society for Optical Engineering.