Simplify the following text for a Grade 12 native English-speaking person.
Original: All tropical waves form in the easterly flow along the equatorward side of the subtropical ridge or belt of high pressure which lies north and south of the Intertropical Convergence Zone ( ITCZ ) .
Simplified: All tropical waves form in the easterly flow along the southern side of the subtropical ridge or belt of high pressure which is located north and south of the Intertropical Convergence Zone ( ITCZ ) .