Global Carbon Assimilation System using a modified Ensemble Kalman filter
报告人： Xiaogu Zheng, Beijing Normal University
时间：2016-05-19 15:00 ~ 16:00
地点：Room 217, Guanghua Building 2
Abstract:
A Global Carbon Assimilation System based on the Ensemble Kalman filter (GCAS-EK) is developed for assimilating atmospheric CO2 data into an ecosystem model to simultaneously estimate the surface carbon fluxes and atmospheric CO2 distribution. This assimilation approach is similar to Carbon Tracker, but with several new developments, including inclusion of atmospheric CO2 concentration in state vectors, using the Ensemble Kalman filter (EnKF) with one-week assimilation windows, using analysis states to iteratively estimate ensemble forecast errors, and a maximum likelihood estimation of the inflation factors of the forecast and observation errors. The proposed assimilation approach is used to estimate the terrestrial ecosystem carbon fluxes and atmospheric CO2 distributions from 2002 to 2008. The results showed that this assimilation approach can effectively reduce the biases and uncertainties of the carbon fluxes simulated by the ecosystem model.
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