Simulation of non-local effects of convection with the hybrid mass flux convection scheme HYMACS
Simulation of non-local effects of convection with the hybrid mass flux convection scheme HYMACS
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使用混合质量通量对流方案 HYMACS 模拟对流的非局部效应
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
A. Bott
中科院分区：
文献类型：
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作者：
V. Kuell;A. Bott
本文提出了混合质量通量对流格式HYMACS，用于模拟非流体静力数值天气预报模式中对流部分分解的湿对流。与经典的质量通量格式不同，HYMACS由于上升气流和下降气流产生净对流质量通量，并产生网格尺度压力梯度力。因此，作为网格尺度的反应，环境沉降可能覆盖多个网格柱。在这里，HYMACS被扩展到阵风锋和细胞运输和老化的非局部影响，以一种对流细胞也可以直接在亚网格尺度上通信的方式，而不是仅通过网格尺度平均值传递信息。该方法利用参数化对流单元的阵风锋亚网格尺度信息，通过向相邻的网格列分配“触发奖励”来启动二次单元。此外，对对流单体分配了一个单体年龄，以参数化云顶高度和降水的时间发展。然后在网格尺度上传输该细胞年龄以模拟对流细胞的平流。通过理想化实验和实际案例实验证明了HYMACS的扩展。
The hybrid mass flux convection scheme HYMACS has been proposed to simulate moist convection in non-hydrostatic numerical weather prediction models with grid sizes at which convection is partially resolved. Different to classical mass flux schemes HYMACS produces a net convective mass flux due to updrafts and downdrafts with resulting grid-scale pressure gradient forces. Thus, as a grid-scale reaction the environmental subsidence may cover several grid columns. Here, HYMACS is extended concerning the non-local effects of gust fronts and cell transport and aging in a way that convective cells can communicate also directly on the subgrid-scale without passing information only via grid-scale averages. Subgrid scale information of gust fronts from parameterized convective cells is used to initiate secondary cells by distributing a "trigger bonus" to neighboring grid columns. In addition, a cell age is assigned to convective cells to parameterize a temporal development in cloud top height and precipitation. This cell age is then transported on the grid-scale to simulate the advection of convective cells. The extentions of HYMACS are demonstrated by means of both idealized and real case experiments.