Comparison of the Moist Parcel-in-Cell (MPIC) model with large-eddy simulation for an idealized cloud
Comparison of the Moist Parcel-in-Cell (MPIC) model with large-eddy simulation for an idealized cloud
复制标题
潮湿包裹细胞 (MPIC) 模型与理想化云的大涡模拟的比较
DOI：
10.1002/qj.3532
复制
发表时间：
2019
影响因子：
8.9
通讯作者：
Böing S
中科院分区：
文献类型：
--
作者：
Böing S
湿热的上升是用来测试最近开发的基本上拉格朗日模式模拟湿对流。在这种单元格内湿包裹（MPIC）模型中，使用多个包裹来表示每个网格单元格中的流动。这样做的优点是，地块提供了一个有效和明确的亚网格尺度流的表示。该模型与欧拉大涡模拟进行了比较，该模型采用了一个版本的气象局NERC云模型（MONC），该模型在更传统的欧拉方案中求解相同的方程。这两种模型对潜热释放和蒸发的影响进行了相同的理想化模拟，而不是特定的大气状况。使用这两种方法，在热力发展的整个过程中，动力学特征的演变相似。由MPIC模式捕获的小尺度涡旋的亚网格尺度特性可以在更精细的网格上显式重建。因此，当使用与MONC相同的网格间距时，MPIC模拟可以解决较小的特征，这对于云中湍流的详细研究很有用。体属性的收敛性也用于比较两个模型。大多数这些属性收敛迅速，虽然液态水的概率分布函数收敛缓慢，网格分辨率在MPIC。这可能意味着目前的包裹混合机制的实现低估了小尺度混合。最后，它显示了如何拉格朗日包裹可以用来研究云空气的起源在MPIC一致的方式。
The ascent of a moist thermal is used to test a recently developed essentially Lagrangian model for simulating moist convection. In this Moist‐Parcel‐In‐Cell (MPIC) model, a number of parcels are used to represent the flow in each grid cell. This has the advantage that the parcels provide an efficient and explicit representation of subgrid‐scale flow. The model is compared against Eulerian large‐eddy simulations with a version of the Met Office NERC Cloud model (MONC) which solves the same equations in a more traditional Eulerian scheme. Both models perform the same idealized simulation of the effects of latent heat release and evaporation, rather than a specific atmospheric regime.Dynamical features evolve similarly throughout the development of the thermal using the two approaches. Subgrid‐scale properties of small‐scale eddies captured by the MPIC model can be explicitly reconstructed on a finer grid. MPIC simulations thus resolve smaller features when using the same grid spacing as MONC, which is useful for detailed studies of turbulence in clouds.The convergence of bulk properties is also used to compare the two models. Most of these properties converge rapidly, though the probability distribution function of liquid water converges only slowly with grid resolution in MPIC. This may imply that the current implementation of the parcel mixing mechanism underestimates small‐scale mixing.Finally, it is shown how Lagrangian parcels can be used to study the origin of cloud air in a consistent manner in MPIC.