Can Numerical Simulations of Equatorial Plasma Bubble Plume Structures be Simplified for Operational and Practical Usage?

Abstract

We argued the merits of having a simplified method to simulate equatorial plasma bubble (EPB) plume structures in the context of practical usage. The presence of EPBs in low-latitude ionosphere during nighttime hours is known to pose significant threat to technological systems that rely on global navigation satellite system (GNSS) and communication satellites (SATCOM). Such threat arises due to steep gradients in ionospheric total electron content (TEC) associated with EPBs and due to amplitude scintillations of radio signals by plasma density irregularities that reside within the EPBs. A capability to realistically model EPB plume structures in simulations would be helpful in providing better technical assessment regarding the severity of such ionospheric threats. A prospect of better assessment would emerge in this case because a realistic model of EPB plume structures could allow for non-stationary scintillation signals to be simulated. This is in contrast to standard phase-screen model of ionospheric scintillations, which typically only considers stationary fluctuations caused by uniformly distributed Fresnelscale plasma density irregularities, not irregularities that are localized within individual branches of the EPB plume structures. Although EPB plume structures can be modeled using first principle physics-based models, such physics-based models tend to be computationally demanding and this limitation could become a significant handicap for practical usage. High-performance computing facilities might be able to offer some remedy, but the aforementioned handicap would remain for those without access to such advanced facilities. In our recent research efforts, we have experimented on some options that utilize the diffusion-limited aggregation (DLA) fractal process to generate bifurcating structures that closely resemble typical EPB plume structures. We combined the numerical DLA algorithm with the International Reference Ionosphere (IRI) model, an empirical zonal drift velocity model, and quasi-dipole geomagnetic field model to simulate EPBs in 3-dimensional configuration. Initial tests of this modeling approach indicate promising results.