653 Simulations of volcanic plumes with the ECMWF/MACC aerosol system Angela Benedetti 1 , Johannes W. Kaiser 1 , Jean-Jacques Morcrette 1 , Reima Eresmaa 1 and Sarah Lu 2 1 European Centre for Medium-Range Weather Forecasts, Reading, UK 2 NCEP Environmental Modeling Center, USA Research Department December 19, 2011