The Intertropical Convergence Zone (ITCZ) is a zone of low-pressure near the equator where two easterly trade winds originating from the Northern and Southern hemispheres converge. This zone of enhanced convection, cloudiness, and rainfall constitutes the rising branch of the meridional Hadley circulation (Fig. 2.4.1). The non-uniform distribution of land and sea introduces zonal asymmetries in heating, which drive an eastwest overturning, known as the Walker circulation, wherein air rises at longitudes of the heating and sinks at the other longitudes. The three-quasi permanent centers of the rising branch of the Walker circulation are located over Indonesia, central Africa, and the Amazon basin (Fig. 2.4.2). From satellite data, the ITCZ can be identified as a meandering band of cold infrared effective temperature and high albedo located over the warmest equatorial region