ENSO and PDO Influence to Climate Variability in Monsoon Region of Indonesia

Abstract

Climate variability can be identified based on two climate parameters: Outgoing Longwave Radiation (OLR) and Precipitable Water (PW). South of Indonesia (2-10°S, 90-15°E) is a rainfall monsoon region with relatively homogeneous characteristics in seasonal variations. However, the region has some certain sensitivities in responding variability from intraseasonal to interannual. Using the method of Empirical Mode Decomposition (EMD), S-Transform and Wavelet for 30 years monthly data of OLR and PW (1980-2011), it was found that both of data indicate signal strengthening after 2010 which is related to Tropical Multi-decadal Mode. Regional response from Intraseasonal to interannual variations confirm that both parameters are sensitive to 1-3 monthly (Intraseasonal Variation) related to MJO, 6 month and 1 year related to monsoon, the 2-7 year variability associated with El Niño Southern Oscillation (ENSO) on short term and medium scale period, whereas 10 yearly due to ENSO in longterm scale period and probably represent the phenomenon of the solar cycle. However it may be suggested that the 15 and 30 year variability would probably corresponded with ENSO and the Pacific Decadal Oscillation (PDO).