Effects of El Niño-induced climate change on CO2 concentrations and the carbon cycle in East Asia

This study examined the effects of 2009/10 and 2015/16 El Niño events on meteorological states and the carbon cycle in East Asia, using surface CO2 observational data and high-resolution meteorological and CO2 concentration data simulated in the Weather Research and Forecasting model coupled with Chemistry over the 10-year period (2009–2018). The growth rate of atmospheric CO2 concentrations and net ecosystem exchange flux in East Asia were significantly positively correlated with the Niño3.4 SST index six to nine months and five to seven months, respectively, after the El Niño peak. Temperature anomalies exhibited distinct spatial characteristics, with negative (positive) anomalies in the developing (decaying) summer of the El Niño. The temperature anomalies mainly led to changes in vegetation respiration, which subsequently contributed to a rapid increase in atmospheric CO2 concentrations after El Niño. The findings for the interactions between El Niño and the carbon cycle provide fundamental insights for enhancing our understanding of the potential impacts of future climate variability on the carbon cycle in East Asia.