Assessing the changes of precipitation extremes in Peninsular Malaysia

The rise of global surface temperature due to warming climate is expected to increase the intensity and occurrence of extreme precipitation events. Previous studies in Southeast Asia revealed complex variations in changes of precipitation extremes. This study presents a spatial-temporal analysis on changes of precipitation extremes in Peninsular Malaysia by utilizing long-term daily rainfall records at 64 observed stations during 1989-2018. The modified Mann-Kendall and Sen's slope tests were performed to detect the significance and magnitude of trends in eight extreme precipitation indices recommended by the Expert Team on Climate Change Detection and Indices. Statistically significant increasing trends are observed for four of these extreme indices in the annual assessment. Spatial analysis demonstrates an obvious contrast between wet and dry regions in patterns of precipitation extremes. Seasonal analysis reveals the intensity and frequency of wet extremes are enhanced significantly during the northeast monsoon season. Significant correlations are found between precipitation extremes and El Nino-Southern Oscillation, particularly in the northern, eastern and southwest regions. Collectively, the evidence presented suggests that the occurrence of precipitation extremes in Peninsular Malaysia tends to be more frequent and intense over the year and is closely associated with the combined effects of tropical monsoon cycles and El Nino-Southern Oscillation.

Automated summary

This study analyzes the changes of precipitation extremes in Peninsular Malaysia based on long-term rainfall records. The findings show that the intensity and occurrence of extreme precipitation events have increased in response to the rise of global surface temperature. The study also reveals regional and seasonal variations in precipitation extremes in Peninsular Malaysia and their correlation with the El Nino-Southern Oscillation.