Upscaling Northern Peatland CO2 Fluxes Using Satellite Remote Sensing Data

Peatlands play an important role in the global carbon cycle as they contain a large soil stock. However, current climate change could potentially shift peatlands from being sinks to sources. Remote sensing methods provide opportunity monitor dioxide (CO2) exchange peatland ecosystems at scales under these changing conditions. In this study, we developed empirical models of CO2 balance (net ecosystem exchange, NEE), gross primary production (GPP), and respiration (ER) that be used for upscaling fluxes with remotely sensed data. Two three years eddy covariance (EC) data five Sweden Finland were compared modelled NEE, GPP ER based on vegetation indices 10 m resolution Sentinel-2 MSI land surface temperature 1 km MODIS To ensure precise match between EC observations, footprint model was applied derive footprint-weighted daily means indices. Average parameters all sites acquired leave-one-out-cross-validation procedure. Both gave high agreement EC-derived (R2 = 0.70 0.56, NRMSE 14% 15%, respectively). The performance NEE weaker (average R2 0.36 13%). Our findings demonstrate using optical thermal satellite sensor is feasible method northern boreal peatlands, although further studies are needed investigate sources unexplained spatial temporal variation fluxes.