Continued Analysis of Convective System Evolution Using Convection-permitting Grid Spacing Weather Research and Forecasting (WRF) Simulations

使用允许对流网格间距天气研究和预报 (WRF) 模拟继续分析对流系统演化

• 批准号: 1222383
• 负责人: William Gallus
• 金额: $ 53.2万
• 依托单位: Iowa State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-11-01 至 2016-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1222383&HistoricalAwards=false
• 关键词: Continued; Analysis; Convective; System; Evolution

This research team will investigate the predictability and upscale evolution of mesoscale convective systems (MCSs) and explore techniques designed to improve quantitative and probabilistic precipitation forecasts of these systems, which serve as a pivotal source of both beneficial and sometimes damaging warm-season rainfall over much of the central U.S. and its associated agricultural belt. Research will focus on numerical model simulations employing fine-mesh "convection-allowing" grid spacings (CAGS) of 2-4 km which explicitly represent thunderstorm-scale circulations and related precipitation processes. Two main research thrusts are planned. The first will emphasize understanding the errors present in simulations from the Weather Research and Forecasting (WRF) model of the nocturnal low-level jet (LLJ), planetary boundary layer (PBL) evolution, and stratiform rain region development and how these features impact simulated MCS evolution. The second thrust will involve evaluations of basic issues related to low-level jet intensity and the role they play in the growth of MCSs. An extensive archive of in-house WRF simulations, output from simulations run by outside collaborators, and data from various observational sources would be incorporated, with intellectual merit centered on advancement of the understanding of (1) relationship of LLJ simulation accuracy to prediction of MCSs; (2) impacts of cloud-solar radiation deficiencies within the PBL on MCS simulations; (3) the role of cloud microphysics and near-storm winds on prediction of MCS evolution; and (4) evaluation of neighborhood methodologies applied to ensemble output to improve convective rainfall prediction.Broader impacts of this research will come through expected improvements in forecasts of warm-season convection, which bring considerable societal benefit due to the disruptive nature of severe weather and flooding events. The researchers plan to work closely with NOAA/National Weather Service personnel to increase the research to operations aspect of the work. Education would also be emphasized, with multiple students involved in the research.

该研究小组将调查中尺度对流系统（MCS）的可预测性和高档演变，并探索旨在改善这些系统的定量和概率降水预报的技术，这些系统是美国中部大部分地区及其相关农业带暖季降雨的关键来源。 研究将侧重于采用2-4公里细网格“允许对流”网格间距的数值模式模拟，这种网格间距明确表示雷暴尺度环流和相关降水过程。 计划开展两项主要研究。 第一个将强调理解从天气研究和预报（WRF）模型的夜间低空急流（LLJ），行星边界层（PBL）的演变，层状雨区的发展，以及这些功能如何影响模拟MCS演变的模拟中存在的错误。 第二个重点将涉及与低空急流强度有关的基本问题的评估，以及它们在MCS增长中所起的作用。 一个广泛的内部WRF模拟档案，外部合作者运行的模拟输出，以及来自各种观测来源的数据将被纳入，其智力价值集中在以下方面的理解：（1）LLJ模拟精度与MCS预测的关系;（2）PBL内云-太阳辐射不足对MCS模拟的影响;（3）云微物理和近风暴风在MCS演变预报中的作用;以及（4）评估应用于集合输出以改进对流降雨预报的邻域方法。这项研究的更广泛影响将通过预期的暖季对流预报的改进来实现，由于恶劣天气和洪水事件的破坏性，这带来了相当大的社会效益。 研究人员计划与NOAA/国家气象局人员密切合作，将研究增加到工作的操作方面。 教育也将受到重视，多名学生参与研究。