Cross-Field Current Instabilities in Thin Ionization Layers and the Enhanced Aurora.

Johnson, J. R. ; Okuda, H.

Technical Information Center Oak Ridge Tennessee

关键词: Current instabilities;    Crossed fields;    Aurora;    Magnetic storms;    Ionosphere;   

RP-ID  :  DE2009959386

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

Nearly half of the time, auroral displays exhibit thin, bright layers known as 'enhanced aurora'. There is a substantial body of evidence that connects these displays with thin, dense, heavy ion layers in the E-region. Based on the spectral characteristics of the enhanced layers, it is believed that they result when wave-particle interaction heats ambient electrons to energies at or just above the 17 eV ionization energy of N2. While there are several possible instabilities that could produce suprathermal electrons in thin layers, there has been no clear theoretical investigation which examines in detail how wave instabilities in the thin ionization layers could develop and produce the suprathermal electrons. We examine instabilities which would occur in thin, dense, heavy ion layers using extensive analytical analysis combined with particle simulations.