Current projects

Collisionless shocks in space plasma are regions of heating and acceleration of charged particles and dissipation of kinetic energy. The accelerated particles are in turn the source of electromagnetic emissions from supernova remnants and other astrophysical structures. At high Mach numbers, shocks can be inherently nonstationary and exhibit modulated energy transfer and recurring plasma compression areas in the form of reformation.

The region upstream of a shock can host a plethora of instabilities that result in various plasma waves that heat the particles. Many fundamental physical mechanisms behind instabilities at shocks are not well understood yet. Electron an ion kinetic scale processes (microphysical processes) that give rise to nonlinear evolution of electromagnetic waves and field generation are some of current active areas of investigation.

In this research we aim to investigate plasma processes that lead to generation and reformation of shocks, and heating and energization of electrons and ions.

Figures adopted from Madanian et al. (2021) show a schematic of the shock profile and representations of solar wind ion trajectories at the shock front (top), and in-situ measured magnetic field profiles.

  • Relevant Publications:

  • Hadi Madanian, Imogen Gingell, Li-Jen Chen, Eli Monyek, (2024) Drivers of Magnetic Field Amplification at Oblique Shocks: In-Situ Observations, ApJL, 965, L12, https://doi.org/10.3847/2041-8213/ad3073.

  • Madanian, H., Omidi, N., Sibeck, D. G., Andersson, L., Ramstad, R., Xu, S., Gruesbeck, J. R., Schwartz, S. J., Frahm, R. A., Brain, D. A., Kajdic, P., Eparvier, F. G., Mitchell, D. L., Curry, S. M., (2023) Transient Foreshock Structures Upstream of Mars: Implications of the Small Martian Bow Shock. Geophysical Research Letters, 50, e2022GL101734,https://doi.org/10.1029/2022GL101734.

  • Madanian, Hadi, Steven J. Schwartz, Stephen A. Fuselier, David Burgess, Drew L. Turner, Li-Jen Chen, Mihir I. Desai, and Michael J. Starkey. 2021. “Direct Evidence for Magnetic Reflection of Heavy Ions from High Mach Number Collisionless Shocks.” The Astrophysical Journal Letters 915(1):L19. doi: 10.3847/2041-8213/ac0aee.

  • Madanian, H., M. I. Desai, S. J. Schwartz, L. B. Wilson, S. A. Fuselier, J. L. Burch, O. Le Contel, D. L. Turner, K. Ogasawara, A. L. Brosius, C. T. Russell, R. E. Ergun, N. Ahmadi, D. J. Gershman, and P. A. Lindqvist. 2021. “The Dynamics of a High Mach Number Quasi-Perpendicular Shock: MMS Observations.” The Astrophysical Journal 908(1):40. doi: 10.3847/1538-4357/abcb88.

  • Turner, D. L., L. B. Wilson, K. A. Goodrich, H. Madanian, S. J. Schwartz, T. Z. Liu, A. Johlander, D. Caprioli, I. J. Cohen, D. Gershman, H. Hietala, J. H. Westlake, B. Lavraud, O. Le Contel, and J. L. Burch. 2021. “Direct Multipoint Observations Capturing the Reformation of a Supercritical Fast Magnetosonic Shock.” The Astrophysical Journal Letters 911(2):L31. doi:10.3847/2041-8213/abec78.

Collisionless Shocks

Solar wind is a flow of charged particles from the Sun that carries the interplanetary magnetic field with it. For objects in the solar system, a bow shock is the first line of defense against the supersonic solar wind flow. Aside from extreme solar events, transient solar wind anomalies can also have an influence on lower plasma boundaries and the ionosphere. Magnetic holes or sudden decreases in the magnetic field within an otherwise unperturbed plasma flow are one of such structures. These pressure-balanced structures create high momentum plasma parcels or sheets that can cause disturbances at the bow shock, magnetopause, and the ionosphere. They have recently drawn more attention as more spacecraft observations have indicated the ubiquitous nature of these structures, yet the generation mechanism(s) and propagation dynamics of magnetic holes are unclear.

Magnetic holes can bypass the bow shock and interact with inner plasma boundaries. Large-scale magnetic holes that can have significance for space weather typically show large magnetic shear angles, and some are generated by a reconnecting current sheet in the solar wind. In fact, of all processes that can generate magnetic holes in the solar wind, reconnection can cause longest duration magnetic depressions. Once reconnection begins, the interplanetary magnetic field provides an infinite amount of energy for the process. Some reconnection exhausts in the solar wind span over hundreds of Earth radii.

In this project, our goal is to determine the generation mechanism and propagation dynamics of magnetic holes in the solar wind, and their impact on Earth's mplasma boundaries

Interaction of a reconnecting current sheet (RCS, purple line) with Earth's bow shock and magnetopause [Adopted from Madanian et al. 2022].

Interaction of a reconnecting current sheet (RCS, purple line) with Earth's bow shock and magnetopause [Adopted from Madanian et al. 2022].

Relevant Publications:

  • Hadi Madanian, Li-Jen Chen, Jonathan Ng, Michael Starkey, Stephen Fuselier, Naoki Bessho, Daniel Gershman, Terry Liu, (2024) Interaction of the Prominence Plasma within the Magnetic Cloud of an ICME with the Earth's Bow Shock, The Astrophysical Journal, 976 219, https://iopscience.iop.org/article/10.3847/1538-4357/ad8579.

  • Halekas, J. S., Shaver, S. Azari, A. R., Fowler, C. M., Ma, Y., Xu, S., Andersson, L., Bertucci, C., Curry, S. M., Dong, C., Dong, Y., Fang, X., Garnier, P., Hanley, K. G., Hara, T., Howard, S. K., Hughes, A., Lillis, R. J., Lee, C. O., Luhmann, J. G., Madanian, H., Marquette, M., Mazelle, C., McFadden, J. P., Meziane, K., Mitchell, D. L., Rahmati, A., Reed, W., Romanelli, N., Schnepf, N. R. (2023). The day the solar wind disappeared at Mars. Journal of Geophysical Research: Space Physics, 128, e2023JA031935. https://doi.org/10.1029/2023JA031935.

  • Madanian, Hadi, Terry Zixu Liu, Tai-Duc Phan, Karlheinz Trattner, Tomas Karlsson, and Michael W. Liemohn. 2022. “Asymmetric Interaction of a Solar Wind Reconnecting Current Sheet and Its Magnetic Hole with Earth’s Bow Shock and Magnetosphere”. Journal of Geophysical Research: Space Physics. https://doi.org/10.1029/2021JA030079.

  • Karlsson, Tomas, Henriette Trollvik, Savvas Raptis, Hans Nilsson, and Hadi Madanian. 2021. “Solar Wind Magnetic Holes Can Cross the Bow Shock and Enter the Magnetosheath.” Preprint (submitted to Journal of Geophysical Research: Space Physics). Solar System Physics. doi: 10.1002/essoar.10507799.1.

  • Madanian, H., J. S. Halekas, C. Mazelle, N. Omidi, J. R. Espley, D. L. Mitchell, and J. P. McFadden. 2019. “Magnetic Holes Upstream of the Martian Bow Shock: MAVEN Observations.” Journal of Geophysical Research: Space Physics. doi:10.1029/2019JA027198.

Interaction of Transient Solar Wind Structures with Planetary Bow Shocks

As the size of the obstacle and the interaction region become smaller and comparable to ion gyroradius, ion kinetic effects become increasingly important. While Earth’s dipole field acts as a protective “cushion” against upstream disturbances, at Mars, comets, or Venus solar wind anomalies, magnetic holes, and foreshock structures can interact with and disturb the upper atmosphere.

One of the main questions around Mars research is how the planet lost its atmosphere, and what is the role of the solar wind in that process. Due to the rather small size of Mars and its bow shock, the foreshock events have direct impact on its ionosphere.

At comets, the interaction region is smaller and becomes even more variable in size due to the variation in the neutral outgassing from the nucleus.

A schematic of plasma boundaries around comet 67P (Madanian et al. 2020). Plasma measurements from the Rosetta mission have indicated of a very complex plasma environment around this comet.

Planetary Ionospheres

Relevant Publications:

  • Madanian, H., Hesse, T., Duru, F., Pilinski, M., and Frahm, R.: Ionospheric density depletions around crustal fields at Mars and their connection to ion frictional heating, Ann. Geophys., 42, 69–78, https://doi.org/10.5194/angeo-42-69-2024, 2024.

  • Duru, F., Frahm, R., Hughes, R., Caplice, T., Pierce, J., and Madanian, H., Local Electron Density Depletions on the Martian Upper Ionosphere Obtained from MARSIS: Comparison with ASPERA-3, and MAVEN, and the Connection with Crustal Magnetic Fields. Journal of Geophysical Research: Space Physics, 128, e2023JA031327. https://doi.org/10.1029/2023JA031327.

  • Madanian, H., J. L. Burch, A. I. Eriksson, T. E. Cravens, M. Galand, E. Vigren, R. Goldstein, Z. Nemeth, P. Mokashi, I. Richter, and M. Rubin. 2020. “Electron Dynamics near Diamagnetic Regions of Comet 67P/Churyumov- Gerasimenko.” Planetary and Space Science 187:104924. doi: 10.1016/j.pss.2020.104924.

  • Timar, A., Z. Nemeth, K. Szego, M. Dósa, A. Opitz, and H. Madanian. 2019. “Estimating the Solar Wind Pressure at Comet 67P from Rosetta Magnetic Field Measurements.” Journal of Space Weather and Space Climate 9, A3. doi: 10.1051/swsc/2018050.

  • Timar, Aniko, Z. Nemeth, K. Szego, M. Dosa, A. Opitz, H. Madanian, C. Goetz, and I. Richter. 2017. “Modelling the Size of the Very Dynamic Diamagnetic Cavity of Comet 67P/Churyumov–Gerasimenko.” Monthly Notices of the Royal Astronomical Society 469 (Suppl_2): S723–30. doi: 10.1093/mnras/stx2628.

  • Volwerk, M., G. H. Jones, T. Broiles, J. Burch, C. Carr, A. J. Coates, E. Cupido, M. Delva, N. J. T. Edberg, A. Eriksson, C. Goetz, R. Goldstein, P. Henri, H. Madanian, H. Nilsson, I. Richter, K. Schwingenschuh, G. Stenberg Wieser, and K. H. Glassmeier. 2017. “Current Sheets in Comet 67P/Churyumov-Gerasimenko’s Coma.” Journal of Geophysical Research: Space Physics. doi: 10.1002/2017JA023861.

  • Madanian, H., T. E. Cravens, J. Burch, R. Goldstein, M. Rubin, Z. Nemeth, C. Goetz, C. Koenders, and K. Altwegg. 2016. “Plasma Environment Around Comet 67P/Churyumov-Gerasimenko at Perihelion: Model Comparison with Rosetta Data.” The Astronomical Journal 153(1):30. doi: 10.3847/1538-3881/153/1/30.

  • Nemeth, Z, J. Burch, C. Goetz, R. Goldstein, Pierre Henri, C. Koenders, H. Madanian, K. Mandt, P. Mokashi, and I. Richter. 2016. “Charged Particle Signatures of the Diamagnetic Cavity of Comet 67P/Churyumov–Gerasimenko.” Monthly Notices of the Royal Astronomical Society 462 (Suppl_1): S415–21. doi: 10.1093/mnras/stw3028.

  • Madanian, H., T. E. Cravens, A. Rahmati, R. Goldstein, J. Burch, A. I. Eriksson, N. J. T. Edberg, P. Henri, K. Mandt, G. Clark, M. Rubin, T. Broiles, and N. L. Reedy. 2016. “Suprathermal Electrons near the Nucleus of Comet 67P/Churyumov-Gerasimenko at 3 AU: Model Comparisons with Rosetta Data: Electrons Near Comet 67P: Rosetta Data.” Journal of Geophysical Research: Space Physics 121(6):5815–36. doi: 10.1002/2016JA022610.

  • Broiles, T. W., G. Livadiotis, J. L. Burch, K. Chae, G. Clark, T. E. Cravens, R. Davidson, A. Eriksson, R. A. Frahm, S. A. Fuselier, J. Goldstein, R. Goldstein, P. Henri, H. Madanian, K. Mandt, P. Mokashi, C. Pollock, A. Rahmati, M. Samara, and S. J. Schwartz. 2016. “Characterizing Cometary Electrons with Kappa Distributions.” Journal of Geophysical Research: Space Physics 121(8):7407–22. doi: 10.1002/2016JA022972.