Comparison of Eulerian Bin and Lagrangian Particle-Based Microphysics in Simulations of Nonprecipitating Cumulus
Comparison of Eulerian Bin and Lagrangian Particle-Based Microphysics in Simulations of Nonprecipitating Cumulus
复制标题
非降水积云模拟中欧拉宾和基于粒子的拉格朗日微物理的比较
DOI：
--
复制
发表时间：
2020
影响因子：
3.1
通讯作者：
W. Grabowski
中科院分区：
文献类型：
--
作者：
W. Grabowski
一个单一的nonepositing积云congestus设置应用于比较液滴光谱增长的扩散的水蒸气在欧拉箱和粒子为基础的拉格朗日微物理方案。箱微观物理学表示应用谱密度函数的液滴谱演变。在拉格朗日微物理学中，被称为超级水滴的计算粒子在时间和空间上被跟踪，每个超级水滴代表多个自然云滴。相同的云凝结核（CCN）激活和相同的液滴扩散增长的代表允许比较。搭载方法是用两个方案在一个单一的模拟，一个方案驱动的动态和其他一个搭载模拟流。搭载允许逐点比较液滴光谱预测的两个方案。结果表明，固有的局限性的两个微观物理模拟方法，数值扩散的欧拉方案和有限数量的超液滴的拉格朗日方案的影响。欧拉方案中的数值扩散导致云的上半部分被更多地稀释，从而减小云滴的平均半径。拉格朗日方案通常具有较大的液滴光谱特性的空间波动。一个显着更大的平均光谱宽度在整个云深的bin微物理是两个方案之间的最大差异。每个网格体积的超级液滴的数量增加四倍，光谱分辨率增加两倍，因此箱的数量对结果的影响很小，并且对模拟云属性之间的比较只提供微小的变化。
A single nonprecipitating cumulus congestus setup is applied to compare droplet spectra grown by the diffusion of water vapor in Eulerian bin and particle-based Lagrangian microphysics schemes. Bin microphysics represent droplet spectral evolution applying the spectral density function. In the Lagrangian microphysics, computational particles referred to as superdroplets are followed in time and space with each superdroplet representing a multiplicity of natural cloud droplets. The same cloud condensation nuclei (CCN) activation and identical representation of the droplet diffusional growth allow the comparison. The piggybacking method is used with the two schemes operating in a single simulation, one scheme driving the dynamics and the other one piggybacking the simulated flow. Piggybacking allows point-by-point comparison of droplet spectra predicted by the two schemes. The results show the impact of inherent limitations of the two microphysics simulation methods, numerical diffusion in the Eulerian scheme and a limited number of superdroplets in the Lagrangian scheme. Numerical diffusion in the Eulerian scheme results in a more dilution of the cloud upper half and thus smaller cloud droplet mean radius. The Lagrangian scheme typically has larger spatial fluctuations of droplet spectral properties. A significantly larger mean spectral width in the bin microphysics across the entire cloud depth is the largest difference between the two schemes. A fourfold increase of the number of superdroplets per grid volume and a twofold increase of the spectral resolution and thus the number of bins have small impact on the results and provide only minor changes to the comparison between simulated cloud properties.
影响因子：
5.5
作者：
Hoffmann, F.;Raasch, S.;Noh, Y.
通讯作者：
Noh, Y.
缩放大气模型以模拟 Pi 室中的湍流和云微物理
影响因子：
6.8
作者：
Thomas, Subin;Ovchinnikov, Mikhail;Yang, Fan;van der Voort, Dennis;Cantrell, Will;Krueger, Steven K.;Shaw, Raymond A.
通讯作者：
Shaw, Raymond A.