Impact of the 1997-98 EL NIÑO Event on Lightning Activity over Indonesia

The 1997-98 El Niño is one of the strongest Et Niño Southern Oscillation (ENSO) events of this century. The major impact of the sea surface temperature (SST) change during this El Niño event was the shift in the convection activity from the western to the central and eastern Pacific affecting the response of rain-producing cumulonimbus. As a result, convective rainfalls were suppressed near the western Pacific regions and maritime continents including Indonesia. On the other hand, the lightning activity during EL Niño period increased in contrast (on the average of 57%). As observed by the Tropical Rainfall Measuring Mission (TRMM) Lightning Imaging Sensor (LIS) and Precipitation Radar (PR), the convective storms during El Niño were more intense. This was supported by the facts that the El Niño's storms had greater vertical developments and thicker zones containing ice phase precipitation.