With South America at center, a satellite image captures cloud patterns in the Western Hemisphere on the evening of May 31, 2009.
That same day Air France Flight 447 disappeared, probably off the easternmost coast of South America. The likely crash site is within the intertropical convergence zone, a belt of cloudy, rapidly changing weather that circles the globe near the Equator.
The plane's flight path took it through a tough-to-navigate breeding zone for thunderstorms near the Equator known as the intertropical convergence zone, or ITCZ.
Northern and southern trade winds crash into each other in the globe-encircling ITCZ. By pushing warm, buoyant equatorial air upward, the convergence helps fuel the zone's almost unceasing series of thousands of small storms.
