Impacts of different El Niño events in the decaying summer on the oceanic source of summer rainfall for eastern China: A perspective from stable isotope

Authors: PENG, PEIYI - Chongqing Academy Of Animal Sciences; CHEN, JIE - Wuhan University; Zhang, Xunchang

Submitted to: Journal of Water and Climate Change
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/3/2024
Publication Date: 7/1/2024
Citation: Peng, P., Chen, J., Zhang, X.J. 2024. Impacts of different El Niño events in the decaying summer on the oceanic source of summer rainfall for eastern China: A perspective from stable isotope. Journal of Water and Climate Change. 15(7). Article 3158. https://doi.org/10.2166/wcc.2024.062.
DOI: https://doi.org/10.2166/wcc.2024.062

Interpretive Summary: As the strongest interannual climate signals, various types and phases of El Niño–Southern Oscillation (ENSO) have different influences on oceanic source of summer precipitation in eastern China. The objective of this study is to investigate the impacts of ENSO types and phases (developing and decaying) on oceanic source contributions to summer precipitation in eastern China. Based on the precipitation isotopes dataset generated by isotope-enabled general circulation model (iGCMs) simulations, a three-component mixing model is employed to estimate the spatiotemporal contributions of oceanic moisture to precipitation from 1979 to 2016. Results show that the spatiotemporal patterns of oceanic moisture fraction anomalies during different phases and various types of ENSO are similar to those of advection fraction anomalies. Results also show that oceanic moisture fraction anomalies (ranging between -5% and 9%) present similar but less obvious spatiotemporal patterns to precipitation anomalies (ranging between -30% and 20%). The study established the linkage between ENSO phases and types and summer precipitation anomalies in eastern China. It provides useful information on planning and managing agricultural production in the region based on the development of the ENSO phases and types.

Technical Abstract: As the strongest interannual climate signals, various types and phases of El Niño–Southern Oscillation (ENSO) have different influences on oceanic source of summer precipitation for eastern China. The objective of this study is to investigate the impacts of ENSO types (Central Pacific El Niño, i.e., CPE; Eastern Pacific La Niña, i.e., EPL; Central Pacific La Niña, i.e., CPL; Eastern Pacific El Niño, i.e., EPE) and phases (developing and decaying) on oceanic sources of summer precipitation. Based on the precipitation isotopes dataset generated by isotope-enabled general circulation model (iGCMs) simulations, a three-component mixing model is employed to estimate the spatiotemporal contributions of oceanic moisture to precipitation from 1979 to 2016. Results show that the spatiotemporal patterns of contribution of oceanic moisture to precipitation during developing CPL (EPL) are opposite to that during developing CPE (EPE) under most circumstances. CPL, EPL and EPE in the decaying phases show similar oceanic moisture fraction anomaly patterns with their corresponding developing phases. The spatiotemporal patterns of oceanic moisture fraction anomalies during different phases and various kinds of ENSO are similar to those of advection fraction anomalies. Furthermore, oceanic moisture fraction anomalies (ranging between -5% and 9%) present similar spatiotemporal patterns but less obvious signals than precipitation anomalies (ranging between -30% and 20%), which contain anomalies of ENSO-induced evaporation and transpiration, under various ENSO events.