Lightning and Thunderstorm Studies

GSTDTAP

项目编号	1720600
	Lightning and Thunderstorm Studies
	Paul Krehbiel
主持机构	New Mexico Institute of Mining and Technology
项目开始年	2017
	2017-08-01
项目结束日期	2020-07-31
资助机构	US-NSF
项目类别	Continuing grant
项目经费	638348(USD)
国家	美国
语种	英语
英文摘要	This is a continuation of ongoing research aimed at improving our understanding of lightning discharges and discharge processes, as well as the electrical structure of thunderstorms. The studies will be conducted utilizing the flash-continuous broadband VHF interferometer developed under our current NSF grant, along with 3-D Lightning Mapping Array (LMA) observations and fast and slow electric field change measurements. The observations are able to characterize lightning inside storms with unprecedented detail, both spatially and temporally. A particular initial focus of the studies will be obtaining ground-truth observations for validating optical observations of lightning from space, to be obtained by the Geosynchronous Lightning Mapper (GLM) on board the recently launched GOES-R satellite. Intellectual Merit: The studies will follow up on results obtained in the current grant that showed how high-power narrow bipolar events (NBEs) are produced - namely by a newly-recognized phenomenon called fast positive breakdown. Further investigation showed that the fast breakdown occurs with a wide range of strengths, hinting that potentially all lightning discharges are initiated by the fast positive process. The research will be aimed at substantiating and extending these results from additional observations of NBEs and flash initiation in Florida storms, currently being obtained in abundance at Kennedy Space Center. A particular focus in this regard will be determining how the negative breakdown of intracloud (IC) and negative cloud-to-ground (-CG) flashes develops subsequent to initiation. Another focus will be to home in on the source and cause of highly energetic terrestrial gamma ray flashes (TGFs). TGFs are increasingly being shown to occur during the initial stages on IC and -CG flashes. This has been further demonstrated by ongoing LMA and electric field change observations at the University of Utah's cosmic ray-detecting Telescope Array (TA), which has detected several possible downward TGFs. Additional studies, in this case utilizing the broadband interferometer, are to be obtained at the newly-established High Altitude Water Cherenkov (HAWC) gamma ray observatory, situated at 4 km altitude in southeastern Mexico. Different discharge processes and lightning types, such as precursor, screening, anomalous polarity, and lull discharges will be conducted. Broader Impacts: The GLM validation studies will valuably assist in understanding and interpreting the upcoming GLM observations, which will quickly become a major part of nowcasting in National Weather Service operations. The voluminous, state-of-the-art INTF and LMA data obtained from the KSC study will be archived at KSC and made available online for analysis by investigators and students at other institutions. As part of the GLM validation study, the Washington DC and Wallops VA LMA networks will be joined together and expanded northward to provide detailed lightning coverage over a large extent of the east coast region. Ongoing analysis of the Sakurajima volcano will be providing insights into the electrification processes of volcanic eruptions. Finally, development and dissemination of lightning mapping and related technology to other research communities and operational users will be continued.
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/71465
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Paul Krehbiel.Lightning and Thunderstorm Studies.2017.