Five-day oscillation in East African low-level jet

Abstract

EASTERN edges of the continents are favourable for the deflection of tropical easterlies from the winter hemisphere to the summer hemisphere. Low-level southerly jet stream along the East African coast is the most pronounced manifestation of this deflected air current which feeds into the Indian monsoon current. We have subjected the jet stream data to a smoothing process to filter out noise and then found that this jet stream has a well marked 5-d periodicity. We discuss here whether this 5-d period is related to the well-known 5-d pulsations of the Indian monsoon activity.