以GRAPES—TCM为试验模式,对1109台风“梅花”进行了36次72h的预报试验,通过试验分析了2种边界层参数化方案——MRF方案与YSU方案在不同情况下对台风预报的影响。结果显示:“梅花”路径与强度对边界层方案的变化都表现出一定的敏感性,敏感性大小与对流参数化方案、台风的初始强度等因素有关,强度的敏感性比路径更明显;对弱台风的路径与强度,YSU方案的总体预报效果优于MRF方案,对于强台风,2种边界层方案中MRF方案的路径预报效果更好,哪种方案的强度预报效果更好与对流参数化方案有关;无论何种情况,YSU方案预报的“梅花”强度都明显强于MRF方案,YSU方案预报的降水及感热通量与潜热通量总体上大于MRF方案;YSU方案时更多的感热通量和潜热通量与该方案时边界层更强的湍流混合有关,更多的潜热通量导致更多的降水,从而释放更多的潜热,更多的潜热释放以及更多的感热通量导致台风强度更强。
The GRAPES-TCM is used to make prediction experiments for Typhoon Muifa (1109). Thirty six experiments are made and the integral time is 72 h. By experiments, the influence of two boundary layer parameterization schemes--MRF scheme and YSU scheme on typhoon prediction under different circumstances is analyzed. Theexperiment results show that Muifa track and intensity are both sensitive to the boundary layer scheme' s change. The sensitivity magnitude is related to some other factors such as convection parameterization scheme and typhoon initial intensity. The intensity sensitivity is greater than the track sensitivity. For weak typhoon, the track and intensity predictions with YSU scheme are overall better than that with MRF scheme. For strong typhoon, be- tween the two boundary layer schemes, MRF scheme's track prediction is better. Which scheme' s intensity pre- diction is better is related to the choice of the convection scheme. In all cases, Muifa intensity with YSU scheme is obviously stronger than that with MRF scheme, and the precipitation and the sensible heat flux and latent heat flux with YSU scheme are all greater than that with MRF scheme. When the boundary layer scheme is YSU scheme, the turbulence mixing in the boundary layer is more powerful, which leads to more sensible heat flux and more latent heat flux. More latent heat flux leads to more precipitation which releases more latent heat. More latent heat release and more sensible heat flux lead to stronger typhoon.