[A-CG40] Earth System Observation Impacts on Climate and Ocean Predictions

[ACG40-08] Impact of Ocean Data Assimilation on Sub-Seasonal Forecasts of the Operational Global Coupled Model in Taiwan

*Ming-En Hsieh¹, Hsi-Hsien Tseng^1,2, Chung-Wei Lee², Yun-Chuan Shao³, Yu-Heng Tseng^1,3, Jen-Her Chen² (1.Ocean Center, National Taiwan University, Taiwan, 2.Marine Meteorology and Climate Division, Central Weather Administration, Taiwan, 3.Institute of Oceanography, National Taiwan University, Taiwan)

Keywords:global coupled model, ocean data assimilation, sub-seasonal forecast

In recent years, Central Weather Administration (CWA) in Taiwan has been developing a global coupled ocean–atmosphere model, in collaboration with National Taiwan University. This system is currently operational in the latest version of CWA’s Global Ensemble Prediction System (GEPS) to enhance extended-range weather forecasting. The atmosphere is initialized using a 6-hour cycling data assimilation from the finite-volume cube-sphere global forecast system (FV3GFS), while the ocean is initialized with HYCOM global analyses. To improve model performance, the operational ocean data assimilation system EnKF-C, developed by the Australian Bureau of Meteorology (BoM), is implemented. We evaluate the impacts of assimilating remote and in-situ oceanographic observations on sub-seasonal forecasts within this coupled model system. The verification scores and the capability of predicting Madden-Julian Oscillation (MJO) are compared for several data denial experiments.