Diagnosis of Simulated Deep Convective Upscale Growth Errors and Their Causes

2018年底在阿根廷中部进行的自适应地面观测(Relampago)和云、气溶胶和复杂地形相互作用(Cacti)野外活动对带电、闪电和中/微尺度过程的遥感将研究根据卫星观测能够发展成世界上最高和最大的风暴。这些实地活动将把大量环境和雷达观测集中在受地形调节的风暴启动热点位置，在该位置，单个风暴单元成长为更大、更长寿命和更高影响的系统通常发生在启动地点附近，限制了风暴时间和地点的不可预测性，这一直困扰着以前的现场活动抽样战略。与Relampago和Cacti相关的研究主要集中在改善对拉丁美洲、美国和世界各地许多其他地点的高影响风暴的理解和预测。通过将精心设计的模型模拟与独特的Relampago和Cacti测量结果进行比较，该项目试图在高分辨率天气模式中确定风暴结构和生命周期偏差的根本原因，以便建立减轻这些偏差的方法。通过这一过程，将确定各种环境因素在控制孤立风暴的概率和演变为更具影响力的更大和更持久的系统方面的相对作用。与寿命较短的单细胞风暴相比，寿命较长的大型系统具有更大的社会影响，因为它们与洪水、大冰雹、破坏性大风和龙卷风等高影响天气有关，并对世界许多地区的降雨做出了重大贡献。2018年11月1日至12月15日的自适应地面观测(Relampago)野外活动对电化、闪电和中/微尺度过程的遥感活动，以及2018年8月15日至2019年4月30日的云、气溶胶和复杂地形相互作用(CACTI)实验，将提供全面的现场和遥感数据集，其固定和移动平台能够高度时空地描述阿根廷中部对流风暴及其周围的热动力、运动学和微物理条件的演变。这一地区经历了世界上一些最强烈和最有组织的对流系统，在Sierras de Córdoba地形屏障上集中和频繁地引发深对流，并有可预测的对流单体运动，频繁地在高地附近发展成更大、更长寿命的系统。在这个项目中，将使用Relampago-Cacti现场测量和一组精心设计的模式模拟来研究深对流升级发展为更大、更长寿命的中尺度对流系统的概率、时间、位置和形态。潜在的模型误差将与环境热力学和运动学条件、模型分辨率和微物理的模型参数有关。将研究潜在的模拟深对流高层增长偏差的原因，强调(I)环境热力学和运动学，(Ii)对流气流、微物理和冷池之间的相互作用，以及(Iii)中尺度环流发展对深对流云系的响应。将检验以下假设：1.地形引发的深对流单体高空发展的概率主要受冷池深度和强度以及中低层垂直风切变和不稳定程度的控制。在模拟中，初始深对流单体过于强烈和频繁，加上太大的边缘冰，会产生比观测到的更强或更丰富的冷池，导致比观测到的和过度组织的对流特征更频繁的高层增长。模拟的中尺度流动响应于偏置潜热和冷却分布，加强了模式的深对流高层增长和组织偏向。对流高层增长偏差在最好地再现观测到的对流上升气流运动学和微物理性质的模拟中是最有限的。

The Remote sensing of Electrification, Lightning, And Mesoscale/microscale Processes with Adaptive Ground Observations (RELAMPAGO) and Cloud, Aerosol, and Complex Terrain Interactions (CACTI) field campaigns in late 2018 in central Argentina will study storms that are capable of developing into the tallest and largest in the world according to satellite observations. These field campaigns will focus a large number of environmental and radar observations in a topographically regulated storm initiation hot spot location, where growth of individual storm cells into larger, longer-lived, and higher impact systems commonly occurs in close proximity to initiation locations, limiting unpredictability of storm timing and location that has plagued previous field campaign sampling strategies. Research associated with RELAMPAGO and CACTI is focused around improved understanding and prediction of high impact storms in Latin America, the US, and many other locations around the world.Through comparison of an ensemble of carefully designed model simulations with unique RELAMPAGO and CACTI measurements, this project seeks to identify root causes of storm structure and life cycle biases in high-resolution weather models, so that methods to mitigate these biases can be established. Through this process, the relative roles of various environmental factors in controlling the probability and evolution of isolated storms into more impactful larger and longer-lived systems will be established. Large and long-lived systems have much larger societal impacts than shorter lived, single cell storms because of their association with high-impact weather such as flooding, large hail, damaging winds, and tornadoes, and their significant contribution to rainfall in many regions of the world. Improved representation of their development and life cycle in weather and climate prediction models will improve forecasts that help communities make better-informed decisions that limit their negative impacts and accentuate their positive impacts.The Remote sensing of Electrification, Lightning, And Mesoscale/microscale Processes with Adaptive Ground Observations (RELAMPAGO) field campaign, from 1 November to 15 December 2018, and the Cloud, Aerosol, and Complex Terrain Interactions (CACTI) experiment, from 15 August 2018 to 30 April 2019, will provide comprehensive in situ and remote sensing datasets with fixed and mobile platforms capable of high spatiotemporal characterization of the evolution of thermodynamic, kinematic, and microphysical conditions in and around convective storms in central Argentina. This location experiences some of the most intense and organized convective systems in the world with focused and frequent deep convective initiation over the Sierras de Córdoba orographic barrier and predictable convective cell movement with frequent upscale growth into larger and longer-lived systems near the high terrain.In this project, the probability, timing, location, and morphology of deep convective upscale growth into larger, longer-lived mesoscale convective systems with high impact rainfall and severe weather will be examined using RELAMPAGO-CACTI field campaign measurements and an ensemble of carefully designed model simulations. Potential model errors will be related to environmental thermodynamic and kinematic conditions, model resolution, and model parameterization of microphysics. Causes for potential simulated deep convective upscale growth biases will be studied, highlighting the separate roles of (i) environmental thermodynamics and kinematics, (ii) interactions between convective drafts, microphysics, and cold pools, and (iii) mesoscale circulation development in response to the deep convective cloud system. The following hypotheses will be tested:1. The probability that orographically initiated deep convective cells grow upscale is primarily controlled by cold pool depth and strength coupled with low-mid level vertical wind shear and instability.2. Overly strong and frequent initial deep convective cells with too much large, rimed ice in simulations produce cold pools that are stronger or more abundant than observed, leading to more frequent upscale growth than observed and overly organized convective features.3. Simulated mesoscale flows responding to biased latent heating and cooling distribution reinforce model deep convective upscale growth and organization biases.4. Convective upscale growth biases are most limited in simulations that best reproduce observed convective updraft kinematic and microphysical properties.