Intertropical Convergence Zone: How it works

The devastating flooding and landslides that occurred in Japan on Friday, Saturday and Sunday were the result of record rainfall — in some places, a year's worth of rain fell over the weekend. The precipitation is being caused by the monsoon trough, a part of the Intertropical Convergence Zone, the area near the equator where winds from the northern and southern hemispheres converge, resulting in increased precipitation. This animation explains how the Intertropical Convergence Zone works.