A Study of the African 'Chimney' Region with Schumann Resonance Methods

用舒曼共振方法研究非洲“烟囱”地区

• 批准号: 0003346
• 负责人: Earle Williams
• 金额: $ 29.67万
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-12-01 至 2003-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0003346&HistoricalAwards=false
• 关键词: Study; African; Chimney; Region; Schumann

This grant supports continuing research on the interpretation of Schumann Resonance observations at several sites around the globe. The surface of the planet Earth and the ionosphere that surrounds it constitute a spherical capacitor, which serves as a resonant cavity for extremely low-frequency electromagnetic waves. The amplitude of the fundamental mode (about 8 Hz) is related to world-wide lightning activity. Observations of the Schumann Resonances (SR) at a given location reveal a background signal on which are superimposed transients caused by intense thunderstorms. The three main regions of global lightning activity are tropical Africa, tropical South America, and Indonesia. This work focuses on lightning in the first of these regions, the African convective or "chimney" zone. Observations at the SR field station in Rhode Island indicate a four-to-five day periodicity in lightning activity over Africa. Two possible explanations of this periodicity are African easterly waves or the global 5-day wave. One objective of the program is to analyze the SR data and supporting observations from satellites, rainfall observations, and global weather maps, to determine the cause of the periodicity. Another objective is to explain the apparent tendency for lightning to have positive polarity over the African continent and negative polarity offshore over the Atlantic Ocean.

这笔赠款支持在全球多个地点继续研究解释舒曼共振观测结果。地球表面和周围的电离层构成了一个球形电容器，充当极低频电磁波的谐振腔。基模的振幅（约 8 Hz）与全球闪电活动有关。在给定位置对舒曼共振 (SR) 的观测揭示了背景信号，其上叠加了由强烈雷暴引起的瞬变。 全球闪电活动的三个主要地区是热带非洲、热带南美洲和印度尼西亚。 这项工作的重点是第一个区域的闪电，即非洲对流或“烟囱”区域。 罗德岛州 SR 现场站的观测表明，非洲上空的闪电活动有四到五天的周期性。 这种周期性的两种可能的解释是非洲东波或全球五日波。 该计划的目标之一是分析 SR 数据并支持卫星观测、降雨观测和全球天气图，以确定周期性的原因。另一个目标是解释闪电在非洲大陆上空具有正极性和在大西洋近海上具有负极性的明显趋势。