The 30-50 day variation of convective activity over the western Pacific Ocean with emphasis on the northwestern region

Abstract

Coherent 30-50 day oscillations between regions north and south of 20°N were observed using the latitude-time (y-t) diagram of a convective index along 140°E over the entire 1979 summer. The oscillation in the northern region exhibits a relatively regular north-south movement of deep convective clouds, while the oscillation in the southern region shows enhancement or suppression fluctuations of broad and intensive deep convective clouds with a period of 30-50 days. The southward (northward) movement of the midlatitude oscillation coincides with the suppression (enhancement) of the tropical deep convective clouds. -from Authors