Parameterization of Cloud Microphysics Based on the Prediction of Bulk Ice Particle Properties. Part I: Scheme Description and Idealized Tests
Parameterization of Cloud Microphysics Based on the Prediction of Bulk Ice Particle Properties. Part I: Scheme Description and Idealized Tests
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DOI：
10.1175/jas-d-14-0065.1
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发表时间：
2015-01
影响因子：
3.1
通讯作者：
H. Morrison;J. Milbrandt
中科院分区：
文献类型：
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作者：
H. Morrison;J. Milbrandt
提出了一种冰相微物理参数化的方法，并用于发展一种新的体相微物理方案。所有的冰相粒子都由几种在时间和空间中自由演化的物理性质来代表。该方案采用了四个冰混合比变量，总质量，雾凇质量，雾凇体积，和数量，允许4个自由度的粒子属性使用一个单一的类别。这种方法代表了与传统微物理方案的重大偏离，在传统微物理方案中，冰相水凝物被划分为各种预定义的类别（例如，云、冰、雪和雹）。新方案的液相部分采用标准的两阶矩两类方法。所提出的方法和新的预测粒子特性（P3）计划的完整描述。从理想化模式模拟的二维飑线的结果，说明该计划的整体行为。尽管它使用了一个单一的冰相类别，该方案模拟了真实的广泛的粒子特性在不同地区的飑线，与观测到的冰粒子在真实的飑线。敏感性试验表明，雾淞质量分数和雾淞密度的预报对模拟飑线结构和降水有重要意义。
A method for the parameterization of ice-phase microphysics is proposed and used to develop a new bulk microphysics scheme. All ice-phase particles are represented by several physical properties that evolve freely in time and space. The scheme prognoses four ice mixing ratio variables, total mass, rime mass, rime volume, and number, allowing 4 degrees of freedom for representing the particle properties using a single category. This approach represents a significant departure from traditional microphysics schemes in which ice-phase hydrometeors are partitioned into various predefined categories (e.g., cloud ice, snow, and graupel) with prescribed characteristics. The liquid-phase component of the new scheme uses a standard two-moment, twocategory approach. The proposed method and a complete description of the new predicted particle properties (P3) scheme are provided. Results from idealized model simulations of a two-dimensional squall line are presented that illustrate overall behavior of the scheme. Despite its use of a single ice-phase category, the scheme simulates a realistically wide range of particle characteristics in different regions of the squall line, consistent with observed ice particles in real squall lines. Sensitivity tests show that both the prediction of the rime mass fraction and the rime density are important for the simulation of the squall-line structure and precipitation.