资源环境科技发展态势分析平台

This study applies Orbiting Carbon Observatory‐2 (OCO‐2) column‐averaged dry‐air mole fractions of CO₂ (XCO₂) to constrain CO₂ fluxes during the 2018 Kilauea volcano eruption. CO₂ enhancements (∆XCO₂) of 1–2 parts per million were observed far downwind of the eruption coincident with elevated sulfur dioxide (SO₂) concentrations. The estimated CO₂ emission rate was 77.1±49.6 kilotons per day (kt day^‐1) on 11 July 2018 with most of the uncertainty from modeled winds and XCO₂ retrievals. This emission rate is higher compared to flux estimates made with ground‐based measurements (30‐40 kt day^‐1). However, cross‐sectional flux estimates made using OCO‐2 XCO₂ observations will inherently be larger than ground‐based measurements near the source as these estimates comprise all sources of CO₂ in the vicinity of the eruption (e.g., vegetation and soil burning). This study for the first time uses satellite XCO₂ data ~200 km downwind to estimate CO₂ emissions from a major volcanic eruption.