GFDL - Geophysical Fluid Dynamics Laboratory

Initialization Methodology for Short-term Forecast ? Ensemble Kalman Filter (EnKF)

The GFDL global High-Resolution Atmospheric model (HiRAM) has been used for studying the relationship between climate-change, hurricane seasonal predictions, and inter-seasonal hurricane activities. It is currently being developed to perform short to mid-range tropical cyclone (TC) forecasts, with focus on improving both the tracks and intensity skills. The ensemble Kalman filter (EnKF) data assimilation technique, which eliminates the adjoint or 3D variational minimization while providing the flow-dependent background error covariance automatically, is chosen as the initialization methodology.  Key elements of the software enabling the parallel execution of EnKF within GFDL’s modeling framework (FMS) has been successfully implemented and tested using a low resolution configuration of the forecast model.  The next development phase that incorporates the assimilation of observed sea level pressure and at higher resolutions is ongoing.