Airborne Studies in the North Dakota Thunderstorm Project

北达科他州雷暴项目中的机载研究

• 批准号: 8721820
• 负责人: John Marwitz
• 金额: $ 13.38万
• 依托单位: University of Wyoming
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-02-01 至 1991-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8721820&HistoricalAwards=false
• 关键词: Airborne; Studies; North; Dakota; Thunderstorm

How hail is produced in deep convective storms has been studied for several years, but many questions still remain. It is well-known that hailstones begin their growth around small ice particles which are referred to as hailstone embryos. Results over the last decade have drawn attention to an area in severe storms known as feeder cells. These are small convective clouds that form near the main storm cell and eventually are absorbed ("feed") into the main convective cell. It is speculated that, at least in some types of hailstorms, these feeder cells are the main producers of the embryos that eventually grow into large hail. In conjunction with the National Oceanic and Atmospheric Administration, the National Science Foundation will participate in a field program to study hailstorms. This project, known as the North Dakota Thunderstorm Project, will be held during the Summer of 1989. As part of this research effort, the Principal Investigator intends to study two aspects of embryo production. First, using in situ aircraft measurements, the microphysical characteristics of feeder cells will be investigated. This will include experimental seeding with artificial ice nuclei in the feeder cells to investigate the effects of premature nucleation on microphysical processes. The second area of investigation will focus on a phenomenon known as fine scale reflectivity patterns. These are areas of enhanced radar echo return and have been thought to be a source of hailstone embryos. Through direct sensing, the Principal plans to investigate the hypothesis that these are indeed areas of high concentration of embryos and that these embryos often find their way into the regions of the storm where large hail is produced. //

人们对深对流风暴中冰雹是如何产生的进行了多年的研究，但仍然存在许多问题。 众所周知，冰雹开始在小冰粒周围生长，这些小冰粒被称为冰雹胚胎。 过去十年的结果引起了人们对严重风暴地区（称为馈线区）的关注。 这些是在主风暴单体附近形成的小型对流云，最终被吸收（“供给”）到主对流单体中。 据推测，至少在某些类型的冰雹中，这些饲养细胞是最终成长为大冰雹的胚胎的主要生产者。 美国国家科学基金会将与国家海洋和大气管理局合作参与研究冰雹的实地计划。 这个项目被称为北达科他州雷暴项目，将于 1989 年夏季进行。作为这项研究工作的一部分，首席研究员打算研究胚胎生产的两个方面。 首先，将利用飞机现场测量来研究饲养细胞的微物理特性。 这将包括在饲养细胞中用人造冰核进行实验播种，以研究过早成核对微物理过程的影响。 研究的第二个领域将集中于一种称为细尺度反射率图案的现象。 这些是雷达回波返回增强的区域，被认为是冰雹胚胎的来源。 通过直接传感，校长计划调查以下假设：这些确实是胚胎高度集中的区域，并且这些胚胎经常进入产生大冰雹的风暴区域。 //