资源环境科技发展态势分析平台

The ratio (e-ratio) between net community production (NCP) and net primary production (NPP) is a useful index of carbon export efficiency. Seasonal variations of e-ratio are poorly documented due to the lack of field measurements. In this study the satellite-based NPP and Argo-Oxygen (O₂) based NCP were used to determine e-ratio in the subtropical gyres. Comparisons with long-term field measurements at the Hawaii Ocean Time-Series showed good agreement in annual mean and spring-summer (April-July) e-ratio. With the short-term tracer (O₂) the satellite/Argo approach revealed significant seasonal variations in NCP and e-ratio in the subtropical gyres of the North Pacific, North Atlantic, and South Pacific. The satellite/Argo-derived annual mean e-ratio in all three Northern Hemisphere sites were close to those from the temperature-based empirical model, but significantly lower in the South Pacific subtropical gyre where the sub-annual NCP variations were stronger.