Linked from
The 12 pages that link to West African monsoon, each with the reason it gives.
SaharaRelated: Its northward reach helped sustain past lakes and vegetation in the Sahara.
SahelRelated: Its northward reach determines when and where the Sahel receives summer rain.
Gulf of GuineaRelated: Its ocean moisture supply helps drive the region’s rainy season.
Senegal RiverRelated: Its rains drive the river’s annual rise and flood pulse.