Understanding climate and terrestrial ecosystem responses to “summer El Niño”

The El Niño-Southern Oscillation (ENSO) is the most prominent year-to-year climate variability. Through atmospheric teleconnections, ENSO exerts impacts on Earth´s climate, ecosystems and human societies. ENSO anomalies usually develop in autumn, establish in winter, and decline quickly in spring.

However, an unusual type of El Niño that continues till the summer season emerged in recent years, e.g. in 2018/19, may have caused unprecedented damages.

The “summer El Niño” can potentially occur more often in the future, implied by the geological evidence of persistent ENSO peak shifts in the past.

However, the impacts induced by this novel feature of ENSO on global climate (e.g. teleconnection, monsoon and extreme weather) and terrestrial ecosystem (e.g. vegetation pattern, wildfire and carbon cycling) are still unknown.In this project, I will investigate the ENSO phase shift during the Holocene using proxy reconstructions and multiple climate model Holocene simulations, and design experiments with a state-of-art Earth System model to quantify how this dramatic shift in ENSO timing may lead to massive reorganizations in the coupled Earth system and their potential feedbacks onto ENSO intensity.

This study will advance our understanding of the interplay between climate, terrestrial ecosystem and ENSO, as a step towards better predictability of ENSO impacts, and helps to mitigate the future damages related to ENSO for decision-makers.