The T63 Four-dimensional Data Assimilation Experiments in National Meteorological Center (NMC)

This paper describes an experimental scheme of the four-dimensional data assimilation system in NMC and its experimental results. The results indicate that this assimilation scheme is stable on computation. Using the initial condition provided by the scheme, the 7-day global forecasts were produced by T63L16 medium-range numerical weather prediction spectral model. Comparison of T63L16 prediction system with T42L9 operational one shows that T63 is better than T42.