Data Assimilation Seminar
Dr. Tie Dai (Feb. 1, 2019, 15:30-)
|Affiliation||State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG), Institute of Atmospheric Physics (IAP), Chinese Academy of Sciences (CAS)|
|Title||Development and application of aerosol data assimilation in NICAM|
In contrast to traditional aerosol assimilation systems using a latitude and longitude parallel horizontal grid configuration (like their host models), we develop an aerosol data assimilation system based on the forecast model called Non-hydrostatic ICosahedral Atmospheric Model (NICAM) and the Local Ensemble Transform Kalman Filter (LETKF). The real observations of aerosol optical properties from both the polar orbiting satellite (MODIS) and the next-generation geostationary satellite (Himawari-8) are successfully assimilated to generate aerosol analysis and correct the initial conditions for short-term aerosol forecasting especially over the Eastern Asia. To assimilate asynchronous observations and avoid frequent switching between the assimilation and ensemble aerosol forecasts, the LETKF is also recently extended to the four dimensional LETKF (4D-LETKF), and our results indicate that the performance of the 4D-LETKF within an assimilation window time of 24 hours, is generally comparable to that of the LETKF and significantly enhance the computational efficiency. These results encourage us to more accurately recognize the aerosol impacts on the environment and climate by the aerosol assimilation.
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