Secondary instability generated on the equatorial plasma bubbles wall due to an interaction with midnight brightness wave

Abstract

Interaction between Equatorial Plasma Bubbles (EPBs) and midnight Brightness wave (MBW) was observed over Bom Jesus da Lapa (13.3° S, 43.5° W; Quasi-Dipole geomagnetic latitude of 14.1° S), using OI 630 nm all-sky images. On the night of December 22nd, 2019, an EPB was seen propagating eastward in its fossil stage until it interacted with an MBW. After the interaction, the west walls of EPBs generated secondary instabilities that can be associated with gradient drift instability (GDI) and/or Kelvin–Helmholtz instabilities (KHI). We suggest that the MBW contributed to generate a shear in the EPBs walls due to changes in the thermospheric dynamics, such as neutral wind in the F layer height. Furthermore, spectral analysis of the all-sky images suggests that GDI and/or KHI generated turbulence and helped to dissipate the EPBs.Graphical