WP4 is comprised from two networking activities; Networking atmospheric gas and aerosol observations and Connecting the volcanological community with Volcanic Ash Advisory Centres. Together they will improve source parameters to be included in volcanic ash dispersion models. WP4 aims to connect Volcanological Research Institutes (VRI) with Volcanological Observatories (VO) and to interact with operational institutions such as Volcanic Ash Advisory Centres (VAAC), thereby facilitating databases, models/software or instruments across Europe, making European science more competitive.