Midlatitudinal Special Airglow Structures Generatewd by the Interaction Between Propagating Medium-Scale Traveling Ionospheric Disturbance and Nighttime Plasma Density Enhancement at Magnetically Quiet Time

This paper reports a special midlatitudinal medium-scale traveling ionospheric disturbance (MSTID) event, accompanied by a poleward surge of airglow depletion/enhancement and a bifurcation of depletion during the magnetically quiet period. These special structures were generated during a decreasing height of ionosphere with nighttime plasma density enhancement and increment of airglow emission intensity possibly caused by a passing-by midnight brightness wave. We suggest that the interaction of the passing-by MSTID and nighttime plasma density enhancement resulted in the poleward surge and bifurcation of airglow depletion. The nighttime plasma density enhancement could feed the high plasma density to interact with the airglow depletions of MSTID, causing the poleward surge and bifurcation of airglow depletion by the secondary gradient drift instability. The poleward surged airglow enhancement within two adjacent depletions of MSTID is also firstly reported in this study.

本文报道了一次特殊的中纬度中尺度行波电离层扰动（MSTID）事件，在磁静期间伴有气辉亏损/增强的向极涌动以及亏损的分叉。这些特殊结构是在电离层高度下降期间产生的，同时伴有夜间等离子体密度增强以及可能由午夜亮波经过所导致的气辉发射强度增加。我们认为，经过的MSTID与夜间等离子体密度增强的相互作用导致了气辉亏损的向极涌动和分叉。夜间等离子体密度增强能够提供高等离子体密度与MSTID的气辉亏损相互作用，通过二次梯度漂移不稳定性导致气辉亏损的向极涌动和分叉。本研究还首次报道了在MSTID的两个相邻亏损内的向极涌动的气辉增强。