Abstract Possible impacts of the La Ni?a and La Ni?a Modoki on the precipitation over the Indonesian region were investigated in this study. The analysis used monthly precipitation, sea surface temperature (SST), and pressure level wind for a period January 1948 to December 2013. The results clearly show the change in the distribution of precipitation associated with the La Ni?a Modoki event. The results show a remarkable different impact of those two flavors of La Ni?a event on the precipitation over the Indonesian region. During the boreal summer season in June-July-August (JJA) to boreal autumn season in September-October-November (SON), the La Ni?a Modoki caused a significant increase of precipitation almost all over the Indonesian region, in particular over the Kalimantan, Sulawesi, Papua, and central to northern parts of Sumatra Islands. The condition continued to the boreal winter season (December-January-February; DJF), although the affected regions were narrower compared to those during previous two seasons. The enhanced precipitation was related to warmer SST anomalies in the surrounding sea of the Indonesian region that triggered low-level wind convergence, and increased ascending convective branch of the Walker Circulation leading to enhanced atmospheric convection over the Indonesian region.
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