An international Symposium celebrating 20 years of global atmospheric research enhanced by NDACC/ NDSC observations will be held the November 7–10, 2011 in Saint Paul, Reunion Island, France. The symposium is being organized by the Observatoire de Physique de l'Atmosphere de la Reunion. Attendees will be given the opportunity to visit the Maido Observatory which is scheduled to begin operations in early 2012. A Symposium web site will be available in March 2011 for registration, abstract submission, and booking. The abstract deadline is June 10, 2011. Second Announcement.