Decadal oscillation of autumn precipitation in Central Vietnam modulated by the East Pacific–North Pacific (EP–NP) teleconnection

Abstract

Autumn precipitation over Central Vietnam is associated with an increase in the occurrence of tropical cyclones that lead to frequent flooding and pose a significant threat to lives and property. The present analyses reveal a pronounced decadal oscillation of autumn precipitation in Central Vietnam within the 8-11 year frequency band that is modulated by the East Pacific-North Pacific (EP-NP) teleconnection. The negative phase of the EP-NP pattern is associated with a positive sea surface temperature (SST) anomaly in the South China Sea (SCS) that induces low-level convergence, enhances convection, and increases precipitation over Central Vietnam and adjacent islands including Hainan (China) and the Philippines. This circulation feature around the SCS is embedded in a large-scale circulation associated with SST anomalies across the Pacific Ocean-i.e., cooling in the Eastern and Central tropical Pacific sandwiched by warming in the North and South Pacific as well as the Western Pacific Ocean. The positive phase of the EP-NP features opposite SST and circulation anomalies, with the result being reduced rainfall in Central Vietnam. This out-of-phase relationship and shared decadal spectral coherence between the EP-NP index and autumn precipitation in Central Vietnam might be useful for future climate predictions and flood management.

Climatic variability of the Pacific and Atlantic Oceans and western US snowpack

“…Li et al . () studied the decadal variation of the Eastern Pacific and North Pacific on the precipitation of Vietnam, and identified a significant oscillation pattern that has ENSO‐like tropical Pacific variability.…”

“…ENSO effects are associated with an atmospheric short-wave train (shown as a red dashed line) that is associated with the Aleutian low pressures over the northwestern United States. Li et al (2015) studied the decadal variation of the Eastern Pacific and North Pacific on the precipitation of Vietnam, and identified a significant oscillation pattern that has ENSO-like tropical Pacific variability. Three significant SST regions in the Pacific Ocean were detected for all the predictor periods, and were significantly correlated with snowpack stations in the western United States.…”

“…Additional studies have argued about the teleconnections of decadal variabilities of oceanic‐atmospheric parameters with regard to the hydrology of different region (Dettinger and Diaz, ; Li et al, ). Wang et al .…”

“…Additional studies have argued about the teleconnections of decadal variabilities of oceanic-atmospheric parameters with regard to the hydrology of different region (Dettinger and Diaz, 2000;Li et al, 2015). Wang et al (2012) studied teleconnection pattern of multi-decadal drought variability between Great Basin, which extends through most of Nevada and several contiguous states, and warm-cool phases of interdecadal Pacific Oscillation.…”

Decadal fluctuations in the western Pacific recorded by long precipitation records in Taiwan

“…In addition to the interannual variability, the climate in the Asian-Pacific region also fluctuates with a prominent frequency of 10-to 20-years, referred to as quasi-decadal oscillation (QDO) (Hsu and Chen 2011;Li and Zhou 2014;Li et al 2015). Located in the northwestern Pacific, near the East Asian continent (Fig.…”