The Coupled Ocean-Atmosphere Response Experiment (COARE), the field effort of the Tropical Ocean Global Atmosphere (TOGA) program, recently entered its second phase. Included in this phase of the massive research effort is the addition of two U.S. aircraft from NASA and one aircraft each from Australia and the United Kingdom. NASA's ER-2, which can fly above 95% of the Earth's atmosphere, is being used to observe the upper regions of giant tropical convective cloud systems about 1500–2000 m above the ocean surface. The four aircraft join eight research vessels that have taken on new crews and scientists and are back in an observing position at sea.