The International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) was formed to take advantage of the synergy between several coordinated experiments to study the emissions of aerosols and ozone precursors, their chemical transformations and removal during transport to and over the North Atlantic. The capabilities represented by the consortium will allow an unprecedented characterization of the key atmospheric processes. The combined research conducted in the programs that make up ICARTT will focus in three main areas: regional air quality, intercontinental transport, and radiation balance in the atmosphere.