Influence of the Pacific and Indian Ocean climate drivers on the rainfall in Vietnam

Abstract

Rainfall in Vietnam is strongly influenced by climate drivers which are caused by anomalies in sea surface temperature (SST), sea level pressure (SLP) or geopotential height in the Pacific and the Indian Ocean. This paper analyses the rainfall records at different sites in various regions of Vietnam to determine the influence of the three major climate drivers, the ENSO (El Niño–Southern Oscillation), IPO (Interdecadal Pacific Oscillation) and IOD (Indian Ocean Dipole) and their interaction on the rainfall at each of these sites. A statistical technique called Bayesian model averaging (BMA) is used to discuss and address the uncertainties problem in model and variable selection when fitting observed rainfall data with climate drivers' indices. The results show that the ENSO, IPO and IOD and their interaction overall have very minor roles in influencing the rainfall in Northern Vietnam but they have some influences on the rainfall in the central and southern parts of Vietnam. Furthermore, seasonality analysis shows the spring rainfall in Vietnam is strongly influenced by the ENSO, IOD and ENSO*IOD interaction, with ENSO*IOD interaction strongest in the north. The situation in summer is similar but the IOD is most dominant compared to the ENSO and ENSO*IOD interaction. In autumn, the IOD and ENSO influences on rainfall are weaker while the IPO has strong influence in the Central and Southern Vietnam and no climate driver has any influence in the north. And during winter, the IPO, ENSO and IPO*ENSO interaction are associated with rainfall variability across Vietnam while the IOD influence is insignificant. The results also confirm the previous studies on the teleconnection roles of SST in the Pacific and Indian Oceans on rainfall variability in Vietnam.

Factors affecting interannual variation in late summer rainfall in the Red River Delta of Vietnam

“…However, the anomalous SST over the tropical western Pacific is not statistically significant in the wet years, while a small area of the anomalous SST over the tropical western Pacific is statistically significant at the 90% confidence level in the dry years. These results imply that ENSO has a minor effect on the interannual variation in late summer rainfall in the RRD, which is in good agreement with previous studies (Nguyen et al, 2014;Duc et al, 2018).…”

“…To the best of our knowledge, no efforts have been made to explore the interannual variation in late summer rainfall in the RRD. Most previous studies focused on the interannual relationship between middle or whole summer rainfall in the RRD and ESNO (Nguyen et al, 2014;Gobin et al, 2016;Duc et al, 2018). To fill this gap, the interannual variation in late summer rainfall in the RRD and the possible factors inducing rainfall variability are investigated in this study.…”

Rainwater isotopes in central Vietnam controlled by two oceanic moisture sources and rainout effects

“…In addition to variability across mainland Southeast Asia, studies also investigated the effects of ENSO and the IOD on local rainfall amount. They found a strong spatial variability in the relation of SST anomalies and rainfall anomalies across the Peninsula 36 and throughout the seasons 84 . This emphasises that rainfall amount and do not necessarily correspond, since the impact of ENSO on appears to be consistent across the Peninsula, whereas ENSO induced rainfall variability is spatially heterogeneous 85 .…”

Spatiotemporal Trend Analysis of Precipitation Extremes in Ho Chi Minh City, Vietnam During 1980–2017

“…Although the study only provided brief information about the spatial distribution of trends in extreme precipitation indices, which was primarily based on the magnitude of trends and did not consider the significance and stability of trends, the findings were consistent with our results in term The negative correlations of intensity and frequency of extreme rainfall and ENSO and PDO indicate that HCMC is prone to having higher amounts of rainfall and more extreme events during La Niña and PDO cool phase, and vice versa during El Niño and PDO warm phase. Duc et al (2018) stated that ENSO has significant effects on rainfall in South Vietnam. Moreover, Nguyen-Thi et al (2012) mentioned that ENSO (La Niña events) has strong effects on rainfall due to tropical cyclones in Vietnam.…”