This issue of Annales Geophysicae contains selected papers from the 11th International Symposium on Equatorial Aeronomy (ISEA-11) and the Climate and Weather of the Sun-Earth System (CAWSES) Mini-Workshop. ISEA-11 and the CAWSES Mini-Workshop were hosted by the Institute of Space Science at National Central University and were held at the Civil Servant’s Training Center in Taipei, Taiwan from 9–14 May 2005.