The monsoon trough is part of the Intertropical Convergence Zone ( ITCZ ) which extends into or through a monsoon circulation . The monsoon trough is that portion of the Intertropical Convergence Zone ( ITCZ ) which extends into or through a monsoon circulation , as depicted by a line on a weather map showing the locations of minimum sea level pressure , and as such , is a convergence zone between the wind patterns of the southern and northern hemispheres .