Interdecadal Variability in Myanmar Rainfall in the Monsoon Season (May–October) Using Eigen Methods

In this study, we investigated the interdecadal variability in monsoon rainfall Myanmar region. The gauge-based gridded dataset of Global Precipitation Climatology Centre (GPCC) and Climatic Research Unit version TS4.0 (CRU TS4.0) were used (1950–2019) to investigate summer using empirical orthogonal function (EOF), singular value decomposition (SVD), correlation approaches. results reveal relatively negative anomalies during 1980s, 1990s, 2000s, whereas strong positive identified for 1970s 2010s. dominant spatial mode showed a dipole pattern with total variance 47%. power spectra principal component (PC) from EOF revealed significant peak decadal timescales (20–30 years). positively correlated Atlantic multidecadal oscillation (AMO) negatively Pacific (PDO). that extreme (flood) events occurred phase PDO below-average (drought) PDO. cold (warm phase) AMO was generally associated (positive) rainfall. first SVD indicated warm AMO, suggesting enhanced about 53% square covariance fraction related heavy rain over study region except central eastern parts. second demonstrated sea surface temperature (SST) equatorial (El Niño pattern) SST North Ocean, implying deficit 33% fraction, which could be dry El conditions (drought). third SSTs (La Niña caused enhance 6.7% flood conditions. Thus, extra-subtropical phenomena may affect average trends by enhancing cross-equatorial moisture trajectories into Ocean.