Carbon Monitoring System Flux Net Biosphere Exchange 2020 (CMS-Flux NBE 2020)

Abstract

Abstract. Here we present a global and regionally resolved terrestrial net\nbiosphere exchange (NBE) dataset with corresponding uncertainties between\n2010–2018: Carbon Monitoring System Flux Net Biosphere Exchange 2020 (CMS-Flux NBE 2020). It is estimated using the NASA Carbon\nMonitoring System Flux (CMS-Flux) top-down flux inversion system that\nassimilates column CO 2 observations from the Greenhouse Gases Observing Satellite (GOSAT) and NASA s Observing Carbon Observatory 2 (OCO-2). The\nregional monthly fluxes are readily accessible as tabular files, and the\ngridded fluxes are available in NetCDF format. The fluxes and their\nuncertainties are evaluated by extensively comparing the posterior CO 2 \nmole fractions with CO 2 observations from aircraft and the NOAA\nmarine boundary layer reference sites. We describe the characteristics of\nthe dataset as the global total, regional climatological mean, and regional\nannual fluxes and seasonal cycles. We find that the global total fluxes of\nthe dataset agree with atmospheric CO 2 growth observed by the\nsurface-observation network within uncertainty. Averaged between 2010 and\n2018, the tropical regions range from close to neutral in tropical South\nAmerica to a net source in Africa; these contrast with the extra-tropics,\nwhich are a net sink of 2.5±0.3 \u2009Gt\u2009C/year. The\nregional satellite-constrained NBE estimates provide a unique perspective\nfor understanding the terrestrial biosphere carbon dynamics and monitoring\nchanges in regional contributions to the changes of atmospheric CO 2 \ngrowth rate. The gridded and regional aggregated dataset can be accessed at\n https://doi.org/10.25966/4v02-c391 (Liu et al., 2020).