鞠永茂,王汉杰,钟中,宋帅. 2008. 一次梅雨锋暴雨云物理特征的数值模拟研究[J]. 气象学报, 66(3):381-395, doi:10.11676/qxxb2008.036
一次梅雨锋暴雨云物理特征的数值模拟研究
A simulation study on the characteristics of cloud microphysics of rain storm in a meiyu front.
投稿时间:2006-11-16  
DOI:10.11676/qxxb2008.036
中文关键词:  MM5,梅雨锋,暴雨,Goddard云物理方案,TRMM
英文关键词:MM5,Meiyu front, Torrential rain, Goddard cloud microphysical process, TRMM
基金项目:国家重点基础研究发展规划项目(2006CB400505)和国家自然科学基金(NSFC)项目(40675040)
作者单位
鞠永茂 解放军理工大学气象学院南京, 211101 
王汉杰 中国科学院东亚区域气候 环境重点实验室北京, 100029 
钟中 解放军理工大学气象学院南京, 211101 
宋帅 中国科学院东亚区域气候 环境重点实验室北京, 100029 
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全文下载次数: 1995
中文摘要:
      利用中尺度数值模式MM5(V3.6),选用模式中不同的显式云物理方案,对2003年7月4—5日发生在江淮流域的梅雨锋暴雨过程进行了数值模拟,并根据模拟结果对造成此次暴雨过程的对流云团的微物理特征进行了分析。研究结果表明:(1)具有详细云物理过程的中尺度模式MM5对短时强降水过程具有较好的模拟能力,提高MM5模式的分辨率,可以更好地模拟短时梅雨锋暴雨过程,模式中的Goddard云物理方案的模拟结果要优于Reisner方案和Schultz方案。(2)梅雨锋对流云团是一种复杂的固、液、气三相混合体结构,在云体区域内的平均质量密度分布中,水汽的质量密度最大,其次是霰,而冰晶、雪、云水和雨水的质量密度较小且数值大小彼此接近,各种相态粒子质量密度峰值出现的高度随时间无明显变化。雨水、云冰和霰的质量密度随时间演变规律与地面降水强度的变化特征相一致,近地面层水汽密度随时间的演变规律比地面降水强度提前1—2个小时,水汽通量的辐合对暴雨时段内水汽的补充和维持起到了重要的作用。(3)除了最基本的云水向雨水转化的云微物理过程之外,此次降水过程还显示,在中层500—700 hPa范围内雪、冰晶等冰相粒子首先转化为霰粒子,而霰和云水的结合进一步加速(剧)云水向雨水的转换,成为短时特大暴雨形成不可或缺的动力机制,云物理过程中的相变潜热与对流运动的正反馈机制是促进暴雨维持和发展的最重要热力因子。
英文摘要:
      A heavy rainfall in the meiyu front during July 4-5, 2003 is simulated by use of the non hydrostatic meso-scale model MM5 (V3.6) with different explicit cloud microphysical parameterization schemes. The characteristics of microphysical processes of convective cloud are studied based on the model outputs. The simulation study reveals that: (1) the mesoscale model MM5 is capable of simulating the instant heavy rainfall in the meiyu front. The rainfall simulation is significantly improved when the model resolution is increased. And the Goddard scheme is better than the Reisner or Schultz scheme. (2) The convective cloud in meiyu front has a comprehensive structure composing of solid, liquid and vapor phases of water, the mass density of water vapor is the largest one in the cloud; the next one is graupel, while those of ice, snow, rain water, and cloud water are almost equal. The mass density peak heights for different coagulations are almost unchangeable during the heavy rainfall period. The mass density variations of rainwater, cloud ice and graupel are consistent with that of ground precipitation, while that of water vapor in the low levels is 1-2 hours earlier than ground precipitation. (3) The main contribution to the water vapor budget in the atmosphere is the convergence of vapor flux through advection and convection, which provides the main vapor source of the precipitation. Except the basic process of the conversion of cloud water into rainwater, there is an additional cloud micro-physical process that is dynamically indispensable for the formation of instant heavy rainfall. In this process, the ice phase crystals between 500-700 hPa converse into graupels first and then the enhanced mixing of graupels and cloud water accelerates the conversion of cloud water into rainwater. The positive feedback mechanism between latent heat release and convection is the most important thermal factor promoting the maintenance and development of the heavy rain.
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