Sonwalkar Vikas S, Reddy Amani
Department of Electrical Engineering, University of Alaska Fairbanks, Fairbanks, AK 99709, USA.
Geophysical Institute, University of Alaska Fairbanks, Fairbanks, AK 99709, USA.
Sci Adv. 2024 Aug 16;10(33):eado2657. doi: 10.1126/sciadv.ado2657.
Lightning-generated whistlers profoundly affect the energetic particle population in Earth's radiation belts, influencing space weather and endangering astronauts and satellites. We report the discovery of specularly reflected (SR) whistler in which the lightning energy injected into the ionosphere at low latitudes reaches the magnetosphere after undergoing a specular reflection in the conjugate ionosphere, contradicting previous claims that lightning energy injected at low latitudes cannot escape the ionosphere. SR whistlers provide a low-latitude channel to transport lightning energy to the magnetosphere. We calculate the relative contributions of SR, magnetospherically reflected, subprotonospheric, and ducted whistlers to the lightning energy reaching the magnetosphere. When SR whistlers are considered, the global lightning energy contribution to the magnetosphere doubles, implying that the previous estimates of the impact of lightning energy on radiation belts may need substantial revisions. Whistler dispersion and intensity analyses quantitatively confirm our results and suggest new remote-sensing methods of the magnetosphere, ionosphere, Earth-ionosphere waveguide, and lightning flashes.
闪电产生的啸声对地球辐射带中的高能粒子群体有深远影响，会影响空间天气并危及宇航员和卫星。我们报告了镜向反射（SR）啸声的发现，其中在低纬度地区注入电离层的闪电能量在共轭电离层中经历镜向反射后到达磁层，这与之前关于在低纬度地区注入的闪电能量无法逃离电离层的说法相矛盾。SR啸声提供了一个将闪电能量传输到磁层的低纬度通道。我们计算了SR、磁层反射、亚质子层和导管啸声对到达磁层的闪电能量的相对贡献。当考虑SR啸声时，全球闪电能量对磁层的贡献增加了一倍，这意味着之前对闪电能量对辐射带影响的估计可能需要大幅修正。啸声色散和强度分析定量地证实了我们的结果，并提出了磁层、电离层、地球-电离层波导和闪电闪光的新遥感方法。
