Studies of Convection, Microphysics and Lightning in the Deep Convective Clouds and Chemistry Experiment (DC3)

深对流云中的对流、微物理和闪电研究及化学实验（DC3）

• 批准号: 1429925
• 负责人: Steven Rutledge
• 金额: $ 67.53万
• 依托单位: Colorado State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-01 至 2018-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1429925&HistoricalAwards=false
• 关键词: Studies; Convection; Microphysics; Lightning; Deep

With this award, the investigators will carry out comprehensive studies of the data collected during the Deep Convection, Clouds and Chemistry Experiment (DC3) conducted during May-June 2013. DC3 collected a comprehensive dataset on cloud dynamics, microphysics and chemistry in a variety of convective events, over three regions, the southeast U.S., the Southern Great Plains and over the semi-arid region of eastern Colorado. The research will address two of the overarching goals of the DC3 program; understanding the gross electrical structure of storms and why particular storms have a so-called "inverted" electrical polarity; and improving our understanding regarding the production of Nitrogen Oxides (NOx) by lightning. The work concerning the electrical structure of storms will utilize comprehensive Doppler and polarimetric radar and lightning mapping network data obtained in DC3 and will include a small sample of storms affected by the High Park wildfire in Colorado. Under the objective to improve how lightning-generated NOx is handled in cloud-chemistry models, the research team will use Lightning Mapping Array observations of total lightning flash rates to improve flash rate parameterizations, contribute to storm scale budget studies aimed at estimating the amount of NOx produced per lightning flash, and refine assumptions regarding where the lightning-generated NOx is "released" into the storm. The research team will relate detailed observations of ice particle types in anvil clouds (aggregates of frozen droplets) to the adjacent deep convection. Under this award, the research team will develop a number of collaborations to enhance this research, including collaborations with scientists that are conducting cloud-chemistry simulations of several DC3 cases using the Weather Research Forecasting-Chemistry (WRF-Chem) model.This research will contribute to the knowledge base regarding the coupling between cloud dynamics, microphysics and electrification/lightning. The research will utilize state of the art radar and lightning mapping information in order to improve our understanding of so-called "inverted" charge structures where positive electrical charge resides in the storm mid-levels, opposed to the more typical structure where negatively-charged hydrometeors resides at mid-levels. Utilizing the comprehensive measurements from DC3,the research team will also address the lightning-NOx problem, that is, quantifying the amount of NOx released in a storm produced by lightning. This work will be done from the point of view of improving required parameterizations for these processes in cloud-chemistry models. Hence this work will be interdisciplinary in nature, bringing together cloud physics and atmospheric chemistry specialists. This work will also improve our understanding as to how deep convection contributes to anvil ice water contents and ice particle types. Hence this work may lead to a better understanding regarding the radiative properties of anvils attached to strong convection. DC3 observations are expected to advance our understanding regarding storm dynamics, microphysics and electrification. Knowledge of these processes will provide a basis for improving the manner by which lightning-generated NOx (LNOx) is considered in cloud-chemistry models. The role of LNOx in contributing to upper tropospheric ozone, a greenhouse gas, can then be improved. In general DC3 results are expected to improve our understanding regarding the impact of deep convection on the chemical composition of the UTLS (upper troposphere-lower stratosphere). Experimental data from the DC3 project will provide important datasets for model comparison exercises and assessment reports.

有了这笔奖金，研究人员将对2013年5月至6月进行的深对流、云和化学实验（DC 3）期间收集的数据进行全面研究。DC 3收集了一个关于云动力学、微物理学和化学的综合数据集，这些数据集发生在三个地区，美国东南部，南部大平原和科罗拉多东部的半干旱地区。该研究将解决DC 3计划的两个总体目标;了解风暴的总体电气结构以及为什么特定风暴具有所谓的“反转”电极性;并提高我们对闪电产生氮氧化物（NOx）的理解。有关风暴电结构的工作将利用在DC 3获得的全面多普勒和偏振雷达和闪电测绘网络数据，并将包括受科罗拉多高公园野火影响的风暴的一小部分样本。在改善云化学模型中如何处理闪电产生的氮氧化物的目标下，研究小组将使用闪电映射阵列对总闪电率的观测来改善闪电率参数化，为旨在估计每次闪电产生的氮氧化物数量的风暴规模预算研究做出贡献，并完善关于闪电产生的氮氧化物“释放”到风暴中的假设。研究小组将详细观察砧云（冻结液滴的聚集体）中的冰粒类型与邻近的深对流。根据该奖项，研究团队将开展一系列合作，以加强这项研究，包括与正在使用天气研究预报-化学（WRF-Chem）模型对几个DC 3案例进行云化学模拟的科学家合作，这项研究将有助于建立云动力学，微物理学和电气化/闪电之间耦合的知识库。这项研究将利用最先进的雷达和闪电测绘信息，以提高我们对所谓的“反向”电荷结构的理解，即正电荷驻留在风暴中层，而不是更典型的结构，即带负电荷的水凝物驻留在中层。利用DC 3的综合测量，研究小组还将解决闪电-NOx问题，即量化闪电产生的风暴中释放的NOx量。这项工作将从改进云化学模式中这些过程所需的参数化的角度进行。因此，这项工作将是跨学科的性质，汇集云物理学和大气化学专家。这项工作也将提高我们的理解，深对流如何有助于砧冰水含量和冰粒类型。因此，这项工作可能会导致更好地了解有关的辐射特性的砧连接到强对流。DC 3的观测有望推进我们对风暴动力学、微物理学和电气化的理解。这些过程的知识将为改进云化学模型中考虑闪电产生的NOx（LNOx）的方式提供基础。这样，LNOx在促成对流层上层臭氧这一温室气体方面的作用就可以得到改善。 一般来说，DC 3的结果预计将提高我们的理解深对流的UTLS（对流层上部-平流层下部）的化学成分的影响。DC 3项目的实验数据将为模型比较工作和评估报告提供重要的数据集。