Citation: | Sun, L. C., Xu, J. Y., Zhu, Y. J., Yuan, W., and Zhao, X. K. (2021). Case study of an Equatorial Plasma Bubble Event investigated by multiple ground-based instruments at low latitudes over China. Earth Planet. Phys., 5(5), 435–449. doi: 10.26464/epp2021048 |
Observational evidence is insufficient to understand how equatorial plasma bubbles (EPBs) form over low latitudes. The mechanism of plasma-density enhancement (formation of “plasma blobs”) at low latitudes is in dispute. In this paper, we use data from multiple ground-based instruments (one all-sky airglow imager, five digisondes, and one Fabry–Perot interferometer) to investigate the evolution of an EPB event that occurred at low latitudes over China on the night of 06 December 2015 (06-Dec-2015). We provide observational evidence that an enhanced equatorward wind most likely induced by a substorm could have initiated the Rayleigh–Taylor instability (RTI) that destabilized several EPB depletions in an upwelling region of a large-scale wave-like structure (LSWS) in the bottomside ionosphere. Those EPB depletions were forced to surge poleward, from nearly 10° to 19° magnetic latitude, two hours before midnight. Smaller-scale bifurcations evolved rapidly from tips of airglow depletions by a secondary