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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

基本信息

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

项目摘要

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.

该补助金支持在地球仪的几个地点继续研究舒曼共振观测的解释。地球的表面和围绕它的电离层构成了一个球形电容器，作为极低频电磁波的谐振腔。基模的振幅（约8 Hz）与全球范围的闪电活动有关。舒曼共振（SR）在一个给定的位置的观测揭示了一个背景信号，其上叠加的瞬变引起的强烈雷暴。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。这项工作的重点是闪电在第一个这些地区，非洲对流或“烟囱”区。在罗得岛的SR野外观测站的观测表明，非洲上空闪电活动的周期为4至5天。这种周期性的两种可能解释是非洲东风波或全球5日波。该计划的一个目标是分析SR数据以及来自卫星的支持观测、降雨观测和全球天气图，以确定周期性的原因。另一个目的是解释闪电在非洲大陆上空具有正极性而在大西洋近海上空具有负极性的明显趋势。