A review on the numerical simulation of equatorial plasma bubbles toward scintillation evaluation and forecasting

Yokoyama, T.

doi:10.1186/s40645-017-0153-6

Cited by 72 publications

(53 citation statements)

References 84 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the growth phase the perturbation electric field associated with the instability is expected to get modified. The growth time of RT plasma instability is nearly 10-60 min (Kelley et al, 1979;Yokoyama, 2017), which is of the same order as that of F-ESF durations reported here for the early phase. It is known that the ambient electric field is a key parameter that plays an important role in the initial linear growth of RT plasma instability (Kelley et al, 1981).…”

Section: Duration Of Active Phase Of Esfsupporting

confidence: 80%

Evolution of Freshly Generated Equatorial Spread F (F‐ESF) Irregularities on Quiet and Disturbed Days

et al. 2018

View full text Add to dashboard Cite

We examined the seasonal and solar flux dependence of the occurrence of freshly generated intermediate scale (100 m to few km) equatorial spread F (ESF) irregularities during magnetically quiet (Q) and disturbed (D) periods. We utilized long‐term (1992–2006 and 2013–2015) amplitude scintillation data on a 251 MHz signal recorded at Tirunelveli (dip lat. 1.5°N ). Also, ionosonde data (1990–2003) recorded at Trivandrum (dip lat. 0.5°N) are used. The presence of fresh ESF (F‐ESF) is identified using the maximum cross‐correlation between intensity variations recorded by two spaced receivers on a magnetic east‐west baseline. We find distinct differences in the seasonal and solar flux dependence of the usual postsunset (<22 LT) generation of F‐ESF on both Q‐ and D‐days. Interesting feature is that F‐ESF linked moderate–strong scintillations are more prevalent on D‐days as compared to Q‐days in both early (18–22 LT) and later (>22 LT) phase of evolution of the irregularities. It directly hints toward the difference in the spatial structuring (spatial scales) of F‐ESF on D‐days as compared to Q‐days. On D‐days, the occurrence of F‐ESF is more likely around midnight and early‐morning hours in all seasons. Whereas on Q‐days, the postmidnight F‐ESF is found to occur mainly during solstices of low solar activity. The possible sources for the generation of F‐ESF around midnight on Q‐days of solstices during low solar activity are examined. We also find that perturbation electric field linked with F‐ESF on D‐days sustains for longer time, which results in longer durations of the active phase of equatorial plasma bubbles.

show abstract

Section: Duration Of Active Phase Of Esfsupporting

confidence: 80%

Evolution of Freshly Generated Equatorial Spread F (F‐ESF) Irregularities on Quiet and Disturbed Days

et al. 2018

View full text Add to dashboard Cite

show abstract

“…Recent results from high‐resolution physics‐based equatorial plasma bubble (EPB) simulations illustrate the structure characteristics. Figure , which is taken from Yokoyama (), shows a representative EPB structure that resulted from bottomside zonal perturbations applied 1 hr earlier. The structure development is mapped along magnetic field lines that terminate at low altitudes in opposite hemispheres.…”

Section: Introductionmentioning

confidence: 99%

A Configuration Space Model for Intermediate‐Scale Ionospheric Structure

et al. 2018

Self Cite

View full text Add to dashboard Cite

Stochastic ionospheric structure is characterized by spectral density functions (SDFs), which are formally the average intensity of Fourier transformations of the electron density structure. Structure elongation along magnetic field lines is typically accommodated by constraining contours of constant spatial correlation to field‐aligned ellipsoidal surfaces. Structure realizations are generated by imposing the square root of the SDF onto uncorrelated random Fourier modes. The approach has been used successfully for interpreting both in situ and remote propagation diagnostics. However, the only connection to the field‐aligned structures generated by the underlying instability mechanism is the correlation scale. This paper introduces a configuration space model that constructs realizations as summations of field‐aligned elemental striations with a prescribed scale and peak electron density. We show that by choosing the contributing scales according to a bifurcation rule and imposing a power law intensity scaling, the corresponding SDF closely approximates an inverse power law. Thus, configuration space realizations can be structured to reproduce prescribed or measured SDFs from one‐dimensional scans. Stochastic variation comes from an imposed random distribution of striation locations, which are defined by their intercept in a reference slice plane. To conform more directly to physics‐based simulations, the striations can be interpreted as voids in the background electron density. The model is designed to support propagation simulations with arbitrary propagation angles relative to the local magnetic field direction. Relations between in situ structure and diagnostic measurements as well as phase screen equivalence can be explored.

show abstract

“…Firstly, physics-based predictions must have the ability to predict the occurrence of EPBs by simulating the background ionospheric conditions; particularly the daily changes in the upward plasma drift near sunset. The next challenge is to then numerically model the formation and small-scale structure(s) of the EPBs themselves (see review by Yokoyama, 2017). In achieving both of these challenges, an EPB prediction capability would be able to forecast the occurrence of EPBs, their spatial extent and their impact on radio waves.…”

Section: A41 Ionospheric Scintillation Predictionmentioning

confidence: 99%

Application usability levels: a framework for tracking project product progress

Halford

Kellerman

Garcia‐Sage

et al. 2019

J. Space Weather Space Clim.

View full text Add to dashboard Cite

Halford et al: Application Usability LevelsThe space physics community continues to grow and become both more interdisciplinary and more intertwined with commercial and government operations. This has created a need for a framework to easily identify what projects can be used for specific applications and how close the tool is to routine autonomous or on-demand implementation and operation. We propose the Application Usability Level (AUL) framework and publicizing AULs to help the community quantify the progress of successful applications, metrics, and validation efforts. This framework will also aid the scientific community by supplying the type of information needed to build off of previously published work and publicizing the applications and requirements needed by the user communities. In this paper, we define the AUL framework, outline the milestones required for progression to higher AULs, and provide example projects utilizing the AUL framework. This work has been completed as part of the activities of the Assessment of Understanding and Quantifying Progress working group which is part of the International Forum for Space Weather Capabilities Assessment.The existing frameworks each focus on tracking a particular type of product, and so do not fully meet the needs of the heliophysics community. Space physics products include observational data, derived indices, modeled outputs, and more. These products are often used together for different purposes. Each user will have different requirements for the application in terms of the type of product, robustness, and accuracy.The unique needs of the space weather community led to the modification of existing research-to-application communication frameworks to create the Application Usability Level (AUL) framework. Applying AULs to model and data analysis efforts can benefit space physics research. These benefits include improving access to collaborators, project transparency, and communication of project results. As the requirements and user interests for each application are unique, the AUL framework uses specifically-tuned metrics. For instance, a research user interested in upper atmospheric coupling may want to know the flux and characteristic energy of precipitating electrons. Similarly, a satellite industry partner may want to predict satellite drag during a geomagnetic storm. A single research project may be able to provide both users with the products they need. However, the different outputs will require different metrics, implementation strategies, and time frames for implementation. Since the AUL framework is highly adaptable, it can help a single research project meet and track both of these user needs.The AUL framework can bolster communication between researchers, users, funding bodies, and stakeholders. Using a standard framework provides a clear path for users and researchers to follow. This improves efficiency assuring that all components from the researchers' project to the user needs are considered. It enables communication about a proposal's dev...

show abstract

A review on the numerical simulation of equatorial plasma bubbles toward scintillation evaluation and forecasting

Cited by 72 publications

References 84 publications

Evolution of Freshly Generated Equatorial Spread F (F‐ESF) Irregularities on Quiet and Disturbed Days

Evolution of Freshly Generated Equatorial Spread F (F‐ESF) Irregularities on Quiet and Disturbed Days

A Configuration Space Model for Intermediate‐Scale Ionospheric Structure

Application usability levels: a framework for tracking project product progress

Contact Info

Product

Resources

About