The linkage of global GPP variation to ENSO during the satellite era

Terrestrial gross primary production (GPP) is the largest carbon flux entering into the biosphere from the atmosphere. It serves as the key driver of global carbon cycle and provides essential matter and energy for life on land. However, terrestrial GPP is still one of the most dynamic variables, which is poorly understood and difficultly predicted, especially at the annual scale. As leading internal climate oscillation, El Niño-Southern Oscillation (ENSO) periodically influences land climate, thus may strongly alter terrestrial GPP variations. Based on satellite data and ecosystem model, we comprehensively examined the impacts of ENSO on global GPP dynamics from 1982 to 2016. We especially focused on the time-lag effect of ENSO on annual GPP variation, and its spatial heterogeneity. Our conclusion about the contrasting responses of GPP to ENSO across hemispheres and climatic zones could help us to better understand the anomaly of global GPP. Climate system could be extremely complicated. Our efforts in linking ENSO with global GPP dynamics provide a simple framework to understand and predict climatic influences on carbon cycles.