[A-CG39] Global Carbon Cycle Observation and Analysis

[ACG39-04] Development of a near-real time simulation system of terrestrial fluxes with a process-based model

*Akihiko Ito^1,2,3 (1.University of Tokyo, 2.JAMSTEC, 3.NIES)

Keywords:Terrestrial carbon budget, Near-real time, Spatiotemporal variation

Early detection of anomalies in greenhouse gas budget is increasingly important for climate management. A near-real time system for early detection has been developed for atmospheric monitoring. Corresponding system for terrestrial ecosystem fluxes has not been well developed, although they are changing rapidly due to human and climatic impacts. This study proposes a near-real time simulation system of terrestrial fluxes using a process-based model, VISIT (Vegetation Integrative SImulator for Trace gases). The model is driven by an operational meteorological data, provisionally the Japanese Reanalysis for Three Quarters of a Century (JRA-3Q). Simulations as of January 2025 are conducted at hourly time step from 1950 to 2024, shortening the latency within one month. Spatial resolution is also provisionally 0.25 degree in latitude and longitude, and land cover and soil properties were derived from high-resolution global datasets. For operational use, a new re-start scheme was implemented to conduct multiple simulations at the same state when spin-up finished. The new real-time system allows us to assess diurnal to decadal variability in terrestrial fluxes, which can be used for a prior information for atmospheric inversion. Further developments are required to include fire and land use impacts, as well as validation with observational data.