HLAFS显式云降水方案及其对暴雨和云的模拟(II)暴雨和云的模拟

在HLAFS业务数值预报模式的动力框架下,利用文章(I)所述的显式云降水方案,对一次暴雨过程和伴随着的云物蓝砸淮伪?雨过程和伴随着的云物泪果表明,显式方案对降水落区和强降水中心位置的预报较原HLAFS的大尺度饱和凝结方案有明显改进.模式能合理地揭示出暴雨发生、发展过程中的云系演变规律和云物理过程.冰相过程对降水、中尺度热力和动力场有明显影响,特别是冰相过程有利于降水的早期的形成速率.与卫星TBB资料的对比分析表明,引进显式方案后,模式能较合理地模拟出云系的轮廓、位置、范围、强度、生消和移向,模式模拟出的云顶温度与卫星测量出的云顶温度较为一致.

EXPLICIT CLOUD SCHEMES OF HLAFS AND SIMULATION OF HEAVY RAINFALL AND CLOUDS, PART II: SIMULATION OF HEAVY RAINFALL AND CLOUDS

Based on the explicit cloud schemes described in Part I, a heavy rainfall event is simulated and analyzed within the dynamical framework of HLAFS. The results show that including explicit cloud schemes in a mesoscale model improved the heavy rainfall forecast and the understanding of its mesoscale characteristics obviously. The simulation results of the explicit schemes were better than that of the old diagnostic cloud scheme of HLAFS for rainfall location. The mesoscale model including explicit schemes is able to reveal the cloud field evolution and cloud physical characteristics during heavy rainfall development. Ice phase cloud microphysics processes have significant effects on mesoscale processes and their thermal and dynamical structure, especially for precipitate production and maintenance of heavy rainfall during its early developing stage. The outline, location, strength, scale, formation and dissipation, and moving direction of a cloud system are well simulated in general compared with satellite TBB data. The simulated cloud top temperature is in agreement with Satellite TBB.