A project within BIBEX. STARE is an aircraft– and ground–based measurement programme initiated in May 1990 by a committee of scientists from Europe, Brazil and the U.S. to investigate the sources of trace gases, their atmospheric transport, and the chemical processes in the atmosphere which lead to elevated levels of O3, CO, and other trace gases over the southern tropical Atlantic Ocean. The field campaigns conducted under STARE were TRACE-A, SAFARI, and SA'ARI.