Verification of the T213 global spectral model of China National Meteorology Center over the East-Asia area

摘要

From September 2002, the global spectral model T213L31 has been put into operational use at the National Meteorology Center of China. To acquire a comprehensive assessment of T213's performance, four verifications have been implemented, (1) temporal analysis of its forecast accuracy series; (2) spatial analysis and lag correlation analysis of the forecast accuracy; (3) precipitation verification and (4) comparison between the models of T213, T106 (prior version of T213) and ECMWF. The verification illustrates that, after adopting a finer grid and improving many physical schemes, T213 has largely enhanced its forecast accuracy over its prior version. However, its forecast is still poorer than the ECMWF model, and T213 needs to especially improve its 3～5 days' forecast performance. The precipitation verification indicates that T213's forecast for light rain is up-to-standard (0.561 for 24 h forecast), but the forecast accuracy for the larger precipitation drops rapidly. The time series verification shows that the T213's daily forecast exhibits a seasonal trend: the forecast for summer is worse than other seasons and the forecast accuracy decreases to the minimum at July, which suggests the possible impact of the moisture forecast error on the decreases of weather forecast accuracy. This impact is confirmed by the spatial analysis and lag correlation analysis, which show that the specific humidity's forecast has a lagged influence on the accuracies of both the temperature forecast and the geo-potential height forecast, and therefore indicates that the further improvement on specific humidity forecasting and the related moisture parameterization schemes are the crucial points in the future development of the T213 model.