As part of an effort of the Global Atmosphere Watch (GAW) Scientific Advisory Group on Aerosols, a workshop was held in Hamburg in 2007 to develop a plan for a network of lidar networks called the GAW Aerosol Observation Network (GALION). The meeting consisted of representatives of the major atmospheric lidar observating groups from Europe, South America, Asia and North America. This paper will present the draft plan (a whitepaper which will be submitted to GAW) for GALION.

GALION is expected to be a confederation of existing networks operating on a common minimum schedule with quality assurance and comparibility provided through submission of data to a common data center (expected to be the World Data Center for Aerosols at JRC, Ispra, Italy). Some sites (EARLINET, for example) have been observing on the GALION schedule for some time and can be retroactively placed into the WDCA. Others, such as sites in the US, have begun observing on the GALION schedule this summer. The network envisages multiple levels of sophistication in the lidar technology in the early observations. In South America, network development and capacity building will be the early thrust and discussions of GALION occurred at the 4th Latin American Lidar Conference in June, 2007. This paper will discuss how development of GALION can be aided by participating networks.