Global Thunderstorm Activity and its Effects on the Radiation Belts and the Lower Ionosphere

全球雷暴活动及其对辐射带和低电离层的影响

• 批准号: 0233955
• 负责人: Umran Inan
• 金额: $ 33.5万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-04-01 至 2006-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0233955&HistoricalAwards=false
• 关键词: Global; Thunderstorm; Activity; its; Effects

The project proposes an experimental study of thunderstorm coupling to the radiation belts, characterization of lightning flashes which lead to upward electrodynamic coupling, ionospheric variability and parameters, and global lightning and climatology. Newly discovered precipitation of radiation belt particles by magnetospherically reflecting whistler waves launched by lightning discharges will be measured via the associated localized and transient disturbances of the lower ionosphere. The latter disturbances are sensed remotely by means of their effect on the phase and amplitude of very low frequency (VLF) signals propagating in the nearby earth-ionosphere waveguide. Broadband ELF/VLF radio atmospherics measurements at the Antarctic base Palmer are proposed for the measurement of characteristics waveforms of sferics associated with upward electrodynamic coupling phenomena such as sprites. Recent results indicate that such measurements can be unique and used as a proxy measure for occurrences of intense upward coupling phenomena on a global scale. The unique location of Palmer station facilitates the measurements of sferics originating in lightning discharges over large regions of the globe, including the Americas, Africa, and the Atlantic and Pacific oceans. When used together with space-borne measurements, the highly accurate determinations of occurrence time and arrival bearings of sferics as measured at Palmer constitute a powerful new tool for assessment of global lightning activity. VLF observations at Palmer will provide crucial support to a separately funded (by the NSF/OPP) program, operating a VLF beacon transmitter at South Pole. Reception of the beacon signal at Palmer Station will allow the continuous measurement of relativistic electron precipitation from the outer radiation belts, an important component of worldwide efforts to assess "space weather". The proposed program is a part of the international collaboration with Stanford observations at Palmer (PA), complemented by and coordinated with observations at the British station Rothera, the Brazilian base Commandante Ferraz on King George Island (through the collaboration with the Centro de Radio-Astronomia e Aplicacoes Espaciais of Brazil), and at Negev Desert in Israel supported by the University of Tel Aviv. The proposed program complements similar observations carried by Stanford University in the northern hemisphere under the support from the NSF Atmospheric Sciences Division. Coordinated measurements in both the northern and southern hemispheres are needed to study the geomagnetic conjugacy of the phenomena under investigation.

该项目建议对雷暴与辐射带的耦合、导致向上电动力耦合的闪电的特征、电离层的可变性和参数以及全球闪电和气候学进行实验研究。新发现的由闪电发射的磁层反射哨声产生的辐射带粒子的降水将通过相关的低电离层的局部和瞬时扰动来测量。后一种干扰通过其对在附近的地球-电离层波导中传播的甚低频(VLF)信号的相位和幅度的影响而被远程感知。建议在南极帕尔默基地进行宽带ELF/VLF射电大气测量，以测量与精灵等向上电动力耦合现象有关的SERIC的特征波形。最近的结果表明，这种测量可以是独一无二的，并可作为全球范围内发生强烈向上耦合现象的替代测量。帕尔默站的独特位置便于对全球大片地区(包括美洲、非洲、大西洋和太平洋)的闪电放电所产生的SERIC进行测量。当与空间测量一起使用时，在帕尔默测量的发生时间和到达方位的高精度确定构成了评估全球闪电活动的一个强大的新工具。帕尔默的甚低频观测将为一个单独资助的(由NSF/OPP)项目提供关键支持，该项目将在南极运行一个甚低频信标发射机。帕尔默站接收到信标信号后，将能够连续测量来自外辐射带的相对论电子降水，这是评估“空间天气”的全球努力的一个重要组成部分。拟议的方案是与斯坦福大学在Palmer(PA)的国际合作的一部分，与在英国Rothera站、位于乔治王岛的巴西司令部Ferraz(通过与巴西天文中心的合作)以及在特拉维夫大学支持的以色列Negev沙漠的观测相补充和协调。拟议的计划是对斯坦福大学在北半球进行的类似观测的补充，该观测得到了美国国家科学基金会大气科学部的支持。需要在北半球和南半球进行协调测量，以研究所调查现象的地磁共轭。