The result , the lead-lag correlation between PC1 and the Nino3.4 of DJF
shows correlation coefficients are negative (Fig. 5b). The negative correlation between
the PC1 and Nino3.4 indicates the increasing (decreasing) of rainfall over Thailand
6 related to cool (warm) phase of ENSO.
The significant correlations present six months before and after the winter season
that implies the warming SST anomalous over the SA of the Pacific Ocean triggers more
rainfall over the Indochina and after that the rainfall sends signal back to that area of the
Ocean.
From these analyses, they show that the forcing of SST anomalous in the Pacific
Ocean affects rainfall variability over the Indochina. The ENSO does not play a greater role
on rainfall variability comparing to the SA in the North Pacific Ocean. These agree with the
relationship between rainfall in the Southeast Asia and ENSO that shows the large variation
of rainfall over the Borneo (Juneng and Tangang, 2005). Nevertheless, the influence of ENSO
on rainfall variability over the Indochina in this study was shown by the data analysis.
Another perspective given by the modeling is important to give more understanding.
Moreover, the Pacific Decadal Oscillation would be of interest for study further due to it
related to the SST in the North Pacific. There are the plenty of understandings required for
more understanding of climate variability over the Indochina such as the mechanism of SST
forcing affects the rainfall variability.