New Epb High-Resolution Simulation Diagnostics

In a recent paper [Dynamic spectral characteristics of high-resolution simulated equatorial plasma bubbles, Rino, Yokoyama, and Carrano, 10.1186/s40645-018-0243-0] we characterized the structure evolution of a representative development of 5 equatorial plasma bubbles (EPBs) simulated by High-Resolution Bubble (HIRB) model [A review on the numerical simulation of equatorial plasma bubbles toward scintillation evaluation and forecasting., Yokoyama, 10.1186/240645-017-08153-6]. A robust likelihood-based irregularity parameter estimation procedure was used to derive altitude and time dependent two-component power-law structure parameters [On the Characterization of Intermediate-Scale Ionospheric Structure, Rino and Carrano, 10.1029/2018RS006709]. The results verified a two-component structure. Measurements in offset planes verified the magnetic field line mapping of structure identified in the equatorial plane.

Because of the comingling of the structure from individual bubbles, it was difficult to isolate the structure evolution of an isolated EPB. A series of new single-EPB high-resolution simulations were generated by the HIRB model. The effects of increased ion density and structure decay accelerated by reversing the dynamo E field were investigated. This paper will summarize the new structure evolution results. The two-dimensional scintillation theory developed by Carrano and Rino [A theory of scintillation for two-component power law irregularity spectra: Overview and numerical results, 10.1002/2015RS005903] is used to predict the latitudinal distribution of equatorial nighttime scintillation. The results support the hypothesis that field-line mapping of equatorial plane structure can explain the observed latitudinal dependence of magnetic storm related nighttime equatorial scintillation proposed by Bhattacharyya, et al. [Effect of Magnetic Storm Related Thermospheric Changes on the Evolution of Equatorial Plasma Bubbles, Bhattacharyya, Fedrizzi, Fuller, Rowell, Gurram, Kakad, Sripathi, and Sunda, 10.1029/2018JA025995].