I was reading about tropical cyclones and tropical waves and there I saw a study mentioning its relationship with MJO activities. I saw several research papers which discuss about MJO waves. They only mention that a rising sinking pattern travels eastward at a given speed every 40-60 days.
I could not find any detailed mechanism about how these waves are generated near Africa and Western Indian Ocean. How is the wet-dry pattern formed? Does it have any relation with the high radiation in Northern hemisphere summers? If there is any, do these waves emerge during Southern hemisphere summers too?