File : D3.17
Author : Matthias Kuhnert (UAber)
The main objective of the deliverable is to describe the observation based preoperational system that was built to support the verification of land CO2 fluxes reported on an annual basis by national inventory agencies to the UNFCCC. VERIFY achieved one system, which includes bottom up modeling and top down inversions as central parts, as well as additional data sets to complement these approaches. The main objective of the system is to provide each year (in October) an update of observation-based land CO2 fluxes (up to year - 1) that will then be compared to national inventories with synthesis factsheets prepared for the COP meeting each year. The successive steps are: i) first the input data for ecosystem model and inversions are gathered; ii) various bottom up models (from process-based to data driven) are then run; iii) the inversions are then performed using prior flux information from the bottom up models, and iv) all data set are processed in a coherent way to be compared against each other (including national inventories). As key demand the different flux estimates are spatially resolved to allow aggregation per countries or groups of countries. A few directions of improvements were highlighted: e.g. the needs for more precise spatial input data set links to ecosystem management, the need for more atmospheric data and better transport models to reduce inversion uncertainties. One highlight of the preoperational system in VERIFY is the data management, which secures the access of all data to all users (upon registration) and visualizes the results to stakeholders and scientists. One objective of the project was to provide a preoperational system that is transferable to an operational infrastructure such as ICOS or Copernicus in order to improve the national inventories. This requires a precise timeline about the sequence of all steps which has been proposed following a similar approach than the one of the Global Carbon Budget.
