The causal influences of the North Atlantic Oscillation and the Indian Ocean Dipole on the El Niño–Southern Oscillation

Seminar by Prof. Thanh Le from Sejong University

22 August 2019
14:00 - 15:00

The Seminar is being held in Room 1010 (Jasmin) - Intergrated mechanical engineering building. Click here for the campus map.

The El Niño–Southern Oscillation (ENSO), the North Atlantic Oscillation (NAO) and the Indian Ocean Dipole (IOD) are primary sources of global and regional climate variability. Further understanding of possible connections between these climate modes is important for future prediction of extreme events and the associated impacts. Here, we provide evidences for the causal influences of the North Atlantic Oscillation and the Indian Ocean Dipole on the El Niño–Southern Oscillation using output of climate models from Coupled Model Intercomparison Project Phase 5 (CMIP5). The results show significant impact of IOD on ENSO in the 2006–2100 period for 10/22 models. We find robust causal effects of NAO on ENSO for 8 out of 10 models during preindustrial times of past 1000 years (i.e. 850-1850 period). The variations of NAO induce persistent influences on surface atmospheric circulation and temperature over central and eastern tropical Pacific during boreal summer, fall and winter and hence have effects on ENSO development. The results imply that NAO and IOD are potentially predictors of ENSO interannual variability.