Rainfall Anomalies in Greater Indonesia in relation to ENSO and other Factors

The greater Indonesian area suffered through one of its worst recorded droughts during the austral spring of 1997. The extreme El Nino conditions of that year have been associated with that (and many other) climate anomalies of the 1997-98 period. In fact, the link of Indonesian rainfall to Darwin sea level pressure was already discovered and discussed in the early decades of this century. It is noteworthy, however, that there have been drought years in Indonesia that do not fit the El Nino-drought paradigm, such as 1961. Furthermore, the strongest relationships between ENSO and Indonesian rainfall fall into the second half of the calendar year, during the traditional dry season, rather than during the wettest months early in the calendar year.

This presentation gives an overview of ENSO-rainfall relationships over the Maritime Continent since the 1880s. Since quite a few stations have recorded rainfall for more than a century, we can assess the stability of these associations during the active ENSO regimes of 1880-1920 and 1955-95, as well as during the more dormant ENSO regime in between. The impact of regional SST and circulation anomalies will be explored as well for the full record that is available in COADS.