A Step Forward to Global Segment CO2 Flux Estimation Benefiting from Large Swath of Coordinated CO2 and Solar-Induced Fluorescence Measurements from the TanSat-2 Mission

To improve understanding of the global carbon cycle, China is preparing to launch the next-generation carbon monitoring satellite, TanSat-2, which will collect column measurements of carbon dioxide (CO2) and methane (CH4). We investigate the potential of TanSat-2 observations for assessing anthropogenic carbon emissions and ecosystem carbon sinks. To achieve this objective, we introduce a new carbon flux estimation method that combines atmospheric measurements of CO2 and solar-induced fluorescence (SIF) to jointly constrain net primary productivity (NPP) and fossil fuel combustion (FF). We apply EOF (empirical orthogonal function) analysis to the NPP and FF inventories to identify dominant spatiotemporal patterns to reduce the size of the state vector and to help disaggregate the natural and FF sources of CO2. Using observing system simulation experiments (OSSEs)—we find that TanSat-2 CO2 and SIF observations lead to an NPP error reduction of up to 95