Article Figures & Data
Figures
- FIGURE 1
A simplified-yet-realistic, and hence computationally efficient, EPB plume structure model would allow numerous scenarios of low-latitude ionospheric scintillation environments to be simulated. Such an enhanced capacity for conducting ensemble simulations may enable a more comprehensive geospace-environmental hazard characterization, in a Monte-Carlo statistical sense, which could benefit a wide range of modern technological systems that are reliant on satellite links around the equatorial area.
- FIGURE 2
(a) Plume structures of EPBs captured in experimental airglow observations, showing some branching and bifurcation patterns; (b) laboratory-based viscous fingering patterns observed in a Hele-Shaw cell, due to Saffman–Taylor instability; (c) numerical fractal structures generated by the DLA algorithm, which exhibit similar branching and bifurcation patterns; adapted from Makela & Kelley (2003) Halsey (2000b-c).
- FIGURE 3
Basic scheme for the simplified EPB plume structure model simulation: (a) fractal-like branching patterns numerically generated via the DLA algorithm; (b) background ionospheric density generated via the IRI model; (c) model simulation output with the DLA fractal branching patterns embedded onto the background ionospheric density distribution
- FIGURE 4
(a) 3-D view of the simulated EPB plume structures, showing the color-coded ionospheric density on the geomagnetic equatorial plane in the vertical direction and on a surface of maximum plasma density in the horizontal orientation; (b) the same set of simulated EPB plume structures over the South American and Atlantic sectors, represented in terms of ionospheric vertical TEC
- FIGURE 5
(a) Patterns of TEC depletions formed by the simulated EPB plume structures, represented in magnetic latitude, highlighting the characteristic inverse-C morphology of the plumes; (b, c, d) sample real-world observations of inverse-C-shaped EPB plume structures in airglow emission data; adapted from Kelley et al. (2003), Kil et al. (2009), and Comberiate & Paxton (2010)
Note: GLON: geographic longitude; MEQT: magnetic equator
- FIGURE 6
Sequential snapshots showing the growth of DLA-based simulated EPB plume structures from the bottomside nighttime F-region ionosphere to the topside
The growth progression of two representative plumes is tracked.
- FIGURE 7
Comparison of EPB plume structure growth between DLA-based simulations and a few select cases of physics-based simulations
- FIGURE 8
(a) Snapshot of IRI plasma density containing the DLA-based simulated EPB plume structures, with a cross-sectional cut line at 350-km altitude; (b) vertical TEC for various longitudes from the snapshot; (c) ionospheric plasma density along the cross-sectional cut line from the snapshot; (d) power spectral density of the TEC; (e) power spectral density of the ionospheric density at 350-km altitude
- FIGURE 9
(a) Snapshot of IRI plasma density containing the DLA-based simulated EPB plume structures, with a notional LOS pointing vertically at 60°W longitude; (b) keogram of vertical TEC as a function of longitude and UTC, with the dashed line denoting the location of the vertical LOS depicted in the above snapshot; (c) time series plot of TEC along the vertical LOS; (d) power spectral density of the LOS TEC; (e) time series plot of the net ΔTEC along the vertical LOS; (f) time series plot of the apparent TEC gradient
- FIGURE 10
Schematic diagram showing various computational modules involved in a batch run of DLA-based EPB plume structure simulations
Note: ZmF2 is the altitude of maximum ionopsheric plasma density
Tables
EPB Plume Feature Requirement Reference in Literature EPB plume structures start growing at the bottom of the ionospheric F-layer, at an altitude of approximately 150–170 km e.g., Dungey (1956) EPB plume structures typically start to grow shortly after the local sunset period, around 19:00–20:00 SLT e.g., Woodman & LaHoz (1976) EPB plume structures can grow past the altitude of the ionospheric F-peak, and the plume growth would then stagnate e.g., Krall et al. (2010a) The higher the F10.7 solar flux index is, the greater the apex height of the EPB plumes would typically be e.g., Joshi et al. (2022) EPB plume structures generally map north and south from the equatorial plane along geomagnetic field lines e.g., Tsunoda (1980) After initial growth and full development, EPB plumes tend to drift horizontally in the eastward direction e.g., Abdu et al. (1985); Huang et al. (2010) EPB plumes typically develop a westward tilt over time as a result of sheared drift velocity e.g., Kil et al. (2009) EPB plume structures start decaying after local midnight and disappear entirely by the sunrise period e.g., Krall et al. (2010b) Simulation Parameter Variable Content Unit calendar date (year, month, day) yearQ = 2011, monthQ = 03, dayQ = 14 – center longitude of simulation domain lonCTR = −60 deg western longitude limit of simulation domain lonWlim = lonCTR − 65 deg eastern longitude limit of simulation domain lonElim = lonCTR + 65 deg planetary K-index Kp = 2.33 – solar flux index F10.7 = 180 sfu altitude lattice/grid size dh = 10 km longitude lattice/grid size dlon = 0.1 deg time step size dt = 0.05 hr option whether or not to use emulated LSWS pattern for the initial aggregation site use_lsws = ‘Y’ logical option whether or not to use F10.7-dependent EPB apex height ceiling use_apexadjust = ‘Y’ logical wavenumber of emulated LSWS pattern klsws = 2π/5.0 rad / deg lon vertical amplitude of emulated LSWS pattern amplsws = 20 km floor altitude for the DLA fractal process* hminbub = 130 km floor altitude for the DLA fractal process# hminbub = 150 km ceiling altitude for the DLA fractal process† hmaxbub = 497.12 + 6.09 × F10.7 km ceiling altitude for the DLA fractal process‡ hmaxbub = 950 km number of Brownian random-walking “virtual particles” (DLA building blocks) allocated for every 25° longitude of simulation domain 
– - TABLE 3
Summary of Computational Runtimes (MATLAB Implementation on a Laptop Computer) These runtimes cover a 24-hr period, with a time step of 3 min. The simulation domain covers a longitude span of 130°, latitude span of 40°, and altitude range of 0–1100 km.
Module No. Purpose / Description Runtime 1* Initialize simulation parameters 0.001 s 2† Construct EPB plume structures using DLA 682.83 s = 11.4 min 3‡ Render 2-D and 3-D graphics of plume geometry 14091.59 s = 235 min = 3.9 hr 4A* Run IRI model (along vertical plane at magnetic equator) 373.03 s = 6.2 min 4B* Run IRI model (along horizontal plane of ionospheric peaks) 945.89 s = 15.8 min 4C* Run IRI model (along multiple flat horizontal planes) 6408.10 s = 107 min = 1.8 hr 5A‡ Render 2-D graphics of EPB plume structures in terms of Ne 1460.54 s = 24.4 min 5B‡ Render 3-D graphics of EPB plume structures in terms of Ne 8167.83 s = 136 min = 2.3 hr 5C‡ Render 2-D graphics of EPB plume structures in terms of TEC 5248.57 s = 87.5 min = 1.5 hr
Jump to section
- Article
- Abstract
- 1 INTRODUCTION
- 2 BIFURCATING PLUME STRUCTURES OF EPBS
- 3 A SIMPLIFIED OPTION FOR AN EPB PLUME STRUCTURE MODEL
- 4 COMPARATIVE ANALYSIS AND CHARACTERIZATION
- 5 BASIC COMPUTATIONAL PERFORMANCE ASSESSMENT
- 6 POTENTIAL APPLICATIONS
- 7 FURTHER IMPROVEMENTS AND OTHER POTENTIAL ROLES
- 8 SUMMARY AND CONCLUSION
- HOW TO CITE THIS ARTICLE
- CONFLICT OF INTEREST
- ACKNOWLEDGMENTS
- Footnotes
- REFERENCES
- Figures & Data
- Supplemental
- References
- Info & Metrics
Related Articles
Cited By...
- No citing articles found.