Interaction of these easterly winds from the Pacific
with south-westerly flow from the Indian Ocean then produce stronger than normal convergence
and rainfall in Southeast Asia during the La Nina event,
and reduced rainfall during the El Nino events.
Fig.6: Composite maps of the differences between the La Nina and El Nino wind speed anomalies at 850 hPa level and sea level pressure anomalies for the (a) weak-ENSO periods and (b) strong-ENSO periods from 1971 to 2010.