Applied Ensemble Forecast Sensitivity to Observation (EFSO) to LETKF system

The Korea Intitute of Atmospheric Prediction System (KIAPS) has been developing an ensemble data assimilation system based-on the 4-dimensional Local Ensemble Transform Kalman Filter (LETKF) for a global non-hydrostatic model formulated on the cubed-sphere. In this year, we tried to estimate the relative impact of observations on the short-range forecasts by implementing the EFSO (Kalnay et al. 2012) on KIAPS LETKF system. The EFSO is convenient since it uses the ensemble perturbations instead of the adjoint model to derive sensitivity of forecast errors to the analysis. In this presentation, the result of the EFSO applied to our data assimilation system will be shown.