Contributions of auroral electron precipitation and plasma fluid instabilities to the formation of high-latitude ionospheric density structures and scintillation

ROSES ID: NNH20ZDA001N      Selection Year: 2020      

Program Element: Focused Science Topic

Principal Investigator: Matthew D Zettergren

Affiliation(s): Embry-Riddle Aeronautical University, Inc.

Project Member(s):
Datta-Barua, Seebany Co-I/Institutional PI Illinois Institute Of Technology
Hampton, Donald L Co-I/Institutional PI University Of Alaska, Fairbanks
Lamarche, Leslie J Co-I/Institutional PI SRI International
Deshpande, Kshitija Bharat Co-I Embry-Riddle Aeronautical University, Inc.

Summary:

Intermediate scale ionospheric density irregularities can lead to fluctuations in amplitude and phase, i.e. scintillation, of trans-ionospheric radio signals, potentially resulting in degradation of GPS accuracy, scattering of HF radio signals, and other effects. Scintillation is common in high-latitude regions including the cusps, where it has been associated with flow shears and density gradients, and the polar cap, where it has been associated with high-density plasma patches. Background inhomogeneities in the plasma in these regions (strong gradients and flow shears) have led to identification of ionospheric gradient-drift and Kelvin-Helmholtz instability as processes involved in irregularity generation. By contrast, scintillation in the auroral zone is often associated with visible auroral arc structures, suggesting an important role for energetic electron precipitation along with density gradients and complicated flow structures. Due to a confluence of many different processes that could, in principle, contribute to irregularity generation, processes leading to auroral scintillation events are relatively poorly understood compared to their cusp and polar cap counterparts.

The proposed work plans to investigate the role of electron precipitation in producing auroral scintillation by addressing a single top-level science question concerning specific physical mechanisms which lead to scintillation, and the conditions under which auroral scintillation occurs: (SQ) What are the features of density structuring and scintillation produced by electron precipitation (a) directly via impact ionization and (b) indirectly through seeding of ionospheric fluid instabilities triggered from inhomogeneous background conditions?

Comprehensive modeling and data analysis efforts for this project will leverage ionospheric and radio propagation models combined with in situ and remote sensing data from Poker Flat, Alaska. Our ionospheric model, GEMINI, self-consistently describes effects of electron precipitation (i.e. impact ionization, heating, and optical emissions), and fluid-electrodynamic processes responsible for plasma interchange instabilities. GEMINI is coupled to a radio propagation model, SIGMA, to simulate scintillation from a modeled field of density irregularities - creating a full physics based pathway for simulating synthetic scintillation data from hypothetical auroral configurations. These models will be used for physics-based investigations of density irregularities and attendant scintillation produced by precipitation directly (structured impact ionization) and indirectly (seeding of instabilities). High-rate fluctuation data (50 Hz) from the SAGA L-band array at PFRR will be used to directly monitor scintillation during auroral events. Conjunctions between SAGA and other data sources will establish connections between different plasma state parameters and suggest physical mechanisms responsible for structures. Swarm fine-scale measurements of density and drift above the ionosphere, will characterize irregularities and seed structures, while the background state of the ionosphere will be monitored via the Poker Flat Incoherent Scatter Radar. Finally, precipitation will be monitored via inversion of filtered allsky camera measurements which will provide images of structured precipitating electron flux and energy. Data analysis activities will both serve to provide much-improved characterizations of auroral scintillation and to guide selection of parameters for modeling hypotheticals and case studies.

This project directly addresses FST 1 in the B.5 solicitation concerning modeling and validation of irregularities and scintillation and is relevant to LWS program goals 2 and 3 and Heliophysics Decadal survey key science goal 2. The likely role of this project within the FST group is to provide theoretical guidance on sources of auroral small -scale density struc tures and their connection with scintillation.

Publications:

Performance Year	Reference	Investigation Type	Actions
2	Vaggu, P. R.; Deshpande, K. B.; Datta-Barua, S.; Bust, G. S....	Other Investigations

Presentations:

Performance Year	Reference	Actions
2	Blinstrubas, G., "Automated System for High Rate GNSS D... Lamarche, L., “Spectra of Plasma Irregularities around Pol... Lamarche, L., “ISR theory and practice” Guest lecture in... Westerlund, C., Camera and inversion models for auroral scie... Vaggu, P., “Modeling the Effects of Density Structures pro... Zettergren, M., “Stability and structuring of mid-latitude... Gang Li (CoI), et al.: Electron Acceleration at a Shock With... "The Importance of Turbulence and Reconnection in the F... Lynch, B. J., Heliospheric Modeling of Large-scale Interplan... Lynch, B. J., Recent Progress in Numerical Modeling of Erupt... Lynch, B. J., Heliospheric Modeling of Large-scale Interplan... Lynch, B. J., Recent Progress in Numerical Modeling of Erupt... Jull A.J.T., Panyushkina I., Molnár M., Tamas Varga T., Liv... Miyake F., Hakozaki M., Kimura K., Tokanai F., Nakamura, K.,... Panyushkina I., Malyutina T., Jull AJT., Molnar M., Cherkins... Jull, A. J. T., Panyushkina I., Molnar M., Varga T., Livina ... Zhang, S-R, TIDs Associated With the Tonga Eruption: Some Un... AGU 2021: Ground magnetic field perturbation forecasting bas... COSPAR 2021: Modeling and forecasting ground geomagnetic per... Kim, H., Noh, S., Kuzichev, I., Ozturk, D., Xu, Z., Weygand,... Smith, A., Ozturk, D. S., Delamere, P., Lu, G., Kim, H. (202... (INVITED)Maruyama, N., et al (Dec, 2021), “ What can the c... Aikio, A., N. Ellahouny, G. P. Geethakumari, L. Cai, H. Vanh... Breneman, A. W., Using multipoint observations to quantify t... Adhikari, L., Zank, G. P., Zhao, L.-L., Telloni, D., Solar W... Adhikari, L., Zank, G. P., Wang, B., Zhao, L.-L., Telloni, D... Adhikari, L., Zank, G. P., Zhao, L.-L., Wang, B., Tang, B., ... Chen, Y., Small-scale Magnetic Flux Ropes via In Situ Spacec... Chen, Y., PyGS: Analysis tools for small-scale magnetic flux... le Roux, A Tempered Fractional Focused and Parker Transport ... Zhao, L.-L., Effects of Finite Frequency on Turbulence Spect... Xiaocan Li, “Exploring Particle Acceleration and Transport... Xiaocan Li, “Turbulence Properties in 3D Magnetic Reconnec... Xiaocan Li, “Modeling Particle Acceleration and Transport ... Xiaocan Li et al., “Modeling Electron Acceleration and Tra... J. T. Dahlin et al., “Decoding Three-Dimensional Reconnect... Mason, G. M., I. Roth, N. V. Nitta, R. Bučík, D. Lario, G.... GEM 2023: Global Geomagnetic Perturbation Forecasting Using ... LMAG 2023: Using Deep Learning for a Multiscale 'Sun-to...
2	Blinstrubas, G., Y. Su, and S. Datta-Barua, “Automated Sys...

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