Collaborative Research: Strategic Observations of Terrestrial Gamma-Ray Flashes and Related Phenomena

合作研究：地面伽马射线闪光及相关现象的战略观测

• 批准号: 1935989
• 负责人: David Smith
• 金额: $ 65万
• 依托单位: University of California-Santa Cruz
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-02-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1935989&HistoricalAwards=false
• 关键词: Collaborative; Research; Strategic; Observations; Terrestrial

This award supports investigation of understanding terrestrial gamma-ray flashes (TGFs) generated among a small fraction of lightning flashes generated inside thunderstorms. TGFs are extraordinarily powerful bursts of gamma radiation; gamma-rays are particles of invisible light, similar to x-rays but in this case with energies up to about 100 times higher than the x-rays used by doctors and dentists. Although TGFs are rare, the consequences of a direct hit by one of these flashes to a plane full of people are significant. The crew and passengers could receive a very high, sudden dose of dangerous radiation, possibly enough to cause immediate radiation sickness and a significant risk of cancer later in life. An unsolved and interesting problem in atmospheric physics regarding to TGFs is how, why, and when TGFs are produced. The research team seeks understanding of how the gamma-rays get as bright as they do and why (fortunately) they only happen in maybe one out of a thousand lightning flashes based on their current understanding of the ``building blocks'' of a TGF and how high-energy radiation might naturally happen during lightning. The investigation will potentially enable the team to predict involvement of TGFs in lightning flashes that interact with aircraft and provide valuable information on aviation risks for public safety. In this project, the research team will deploy a number of gamma-ray detectors (previously constructed under funding from NSF, NASA, and the Air Force) to ground-based sites, aircraft, and high-altitude balloons in order to gather new data on TGFs in places they have been seen before, such as the western coast of Japan in winter, summer thunderstorms in Florida, and the eyewalls of hurricanes. Each site and the method of observation have been chosen for measurements of TGFs close to their production locations. One of the key observations will be how bright TGFs can get and how faint they get. Currently temporal variations of TGF radiation intensity predicted by leading models have significant uncertainty. To address this uncertainty with consideration of a possible series of rapid bursts of radiation intensity with time, the fast response detector of plastic scintillators for observing each gamma-ray interaction will be used to determine the correct model physics. Combining measurements of lightning characteristics (mostly via radio emission) with complementary meteorological data, the team would be able to understand not only the detailed behavior of lightning that produces TGFs, but also lightning data of similar high quality for situations where a TGF did not get produced, which is equally important to understand.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该奖项支持对雷暴内部产生的一小部分闪电中产生的地面伽马射线闪光（TGF）的研究进行支持。 TGF 是异常强大的伽马辐射爆发；伽马射线是不可见光粒子，类似于 X 射线，但其能量比医生和牙医使用的 X 射线高出约 100 倍。尽管 TGF 很罕见，但这些闪光直接击中一架满载乘客的飞机的后果是严重的。机组人员和乘客可能会突然受到非常高剂量的危险辐射，可能足以立即引起放射病，并在以后的生活中存在患癌症的重大风险。 大气物理学中与 TGF 相关的一个未解决且有趣的问题是 TGF 的产生方式、原因和时间。研究小组试图了解伽马射线如何变得如此明亮，以及为什么（幸运的是）它们只在千分之一的闪电中发生，基于他们目前对 TGF 的“构建模块”的理解以及闪电期间如何自然发生高能辐射。这项调查可能使该团队能够预测 TGF 与飞机相互作用的闪电的参与情况，并为公共安全提供有关航空风险的宝贵信息。在这个项目中，研究团队将在地面站点、飞机和高空气球上部署一些伽马射线探测器（之前由 NSF、NASA 和空军资助建造），以收集新数据在以前见过的地方，例如冬季的日本西海岸、佛罗里达州夏季的雷暴以及飓风的风眼墙，都对 TGF 产生了影响。 每个地点和观察方法均已选择用于测量靠近其生产地点的 TGF。关键的观察结果之一是 TGF 可以变得多亮以及它们变得多暗。目前主要模型预测的 TGF 辐射强度的时间变化具有很大的不确定性。为了解决这种不确定性，考虑到随着时间的推移可能出现的一系列辐射强度快速爆发，用于观察每个伽马射线相互作用的塑料闪烁体快速响应探测器将用于确定正确的模型物理。将闪电特征测量（主要通过无线电发射）与补充气象数据相结合，该团队不仅能够了解产生 TGF 的闪电的详细行为，而且能够了解在 TGF 未获得的情况下类似高质量的闪电数据。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Fair Weather Neutron Bursts From Photonuclear Reactions by Extensive Air Shower Core Interactions in the Ground and Implications for Terrestrial Gamma‐ray Flash Signatures

• DOI: 10.1029/2020gl090033
• 发表时间: 2021-02
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: G. Bowers;X. Shao;William Blaine;B. Dingus;David M. Smith;J. Chaffin;J. Ortberg;H. Rassoul;Cheng Ho;L. Nellen;N. Fraija;C. Álvarez;J. C. Arteaga-Velázquez;V. Baghmanyan;E. Belmont-Moreno;K. Caballero-Mora;A. Carramiñana;S. Casanova;E. de la Fuente;M. González;F. Hueyotl-Zahuantitla;O. Martinez;J. Matthews;E. Moreno;M. Newbold;E. Pérez-Pérez-E.-Pérez-Pérez-1431205495;I. Torres

Special Classes of Terrestrial Gamma Ray Flashes From RHESSI

来自 RHESSI 的特殊类地面伽马射线闪光

• DOI: 10.1029/2020jd033043
• 发表时间: 2020
• 期刊: Journal of Geophysical Research: Atmospheres
• 作者: Smith, D. M.;Kelley, N. A.;Buzbee, P.;Infanger, A.;Splitt, M.;Holzworth, R. H.;Dwyer, J. R.
• 通讯作者: Dwyer, J. R.