Evaluating and Improving Convection-Permitting Simulations of the Life Cycle of Convective Storms using Polarimetric Radar Data

对流风暴是恶劣天气的罪魁祸首，例如大冰雹、山洪暴发和强风。决定这些事件破坏性有多大的一个关键因素是对流系统内的云微物理。云微物理过程直接促成了大冰雹和大降水的形成，但也改变了由于潜热和潜冷而形成对流的环境。对流风暴结构的这些变化也会影响到哪些微物理过程是活跃的，以及风暴中的什么地方。这些复杂的相互作用的存在在最近的许多出版物中都有报道。然而，到目前为止，还没有系统的研究方法来研究云微物理-对流动力学相互作用。在这个项目中，我们将对云微物理过程与对流系统结构之间的相互作用及其对生命周期和由此产生的恶劣天气的影响进行系统的分析。ICON(~1公里分辨率)模式模拟将与从双极化雷达资料中发现的微物理过程、风暴结构和生命周期进行对比。本项目的主要目的是为改进强对流天气事件的允许对流模拟提供一个框架。这将通过1)量化哪些云微物理过程对破坏性降水的产生最重要，2)评估ICON模拟的对流风暴的生命周期、风暴结构和微物理过程与偏振雷达观测的对比情况，3)研究风暴结构和生命周期对微物理过程表示的敏感性。因此，ICON模式将被修改为输出3D微物理过程速率。微物理“搭载”也将被纳入，以区分纯粹的微物理效应和耦合的微物理-动力学效应。在本项目结束时，我们将能够总结ICON目前模拟对流风暴及其破坏性降水的能力，确定哪些过程对破坏性降水的产生最重要，并提出改进建议，以解决目前模式系统中的缺陷。最终结果将不仅是提高对真实对流和模拟对流的理解，而且还将提出具体建议，以提高预测对流造成的破坏性降水的技能。

Convective storms are responsible for severe weather, for example large hail, flash flooding and strong wind gusts. A critical factor that determines how damaging these events are is the cloud microphysics within the convective system. The cloud microphysics processes directly contribute to the formation of large hail and rain, but, additionally, modify the environment in which the convection develops due to latent heating and cooling. These changes to the structure of the convective storm also then affect which microphysical processes are active, and where in the storm. The existence of these complex interactions have been reported in numerous recent publications. However, to date there are no studies taking a systematic approach to investigating the cloud microphysics – convective dynamics interactions. In this project, we will perform a systematic analysis of the interactions between cloud microphysics processes and convective system structure and the effects on the lifecycle and resulting severe weather. Model simulations with ICON (~1 km resolution) will be evaluated against the microphysics processes, storm structure and lifecycle found from dual-polarization radar data.The main aim of this project is to provide a framework for the improvement of convection-permitting simulation of severe convective weather events. This will be achieved by 1) quantifying which cloud microphysics processes are most important for the production of damaging precipitation, 2) evaluation of how well the life cycle, storm structure and microphysical processes of convective storms simulated by ICON compares to polarimetric radar observations 3) investigation of the sensitivity of the storm structure and lifecycle to the representation of microphysical processes.Therefore, the ICON model will be modified to output the 3D microphysical process rates. Microphysical “piggybacking” will also be incorporated, to separate purely microphysical effects from coupled microphysical-dynamical effects.At the conclusion of this project, we will be in a position to summarise the current ability of ICON to simulate convective storms and their damaging precipitation, identify which processes are most important for the production of the damaging precipitation, and recommend improvements to address current shortcomings in the model system. The end result will be not just an improved understanding of both real and modelled convection, but also specific recommendations to increase skill of predicting damaging precipitation from convection.