Konstantinos Papadakis

Derivation of Pitch-Angle-Dependent Radial Diffusion Coefficients of off-Equatorial Relativistic Electrons in the Radiation Belts

Theodore Sarris, Weichao Tu, Hong Zhao, Xinlin Li et autres

Radial diffusion of energetic electrons by Ultra-low frequency (ULF) waves is a key mechanism for the acceleration and radial transport of hundreds-keV to few-MeV electrons in the radiation belts, via their drift-resonant interactions. Until recently, estimates of the radial diffusion rates have …

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Quantification of non-Maxwellian properties in plasma mixing during magnetopause reconnection

Ivan Zaitsev, Konstantinos Papadakis, Markku Alho, Sanni Hoilijoki et autres

We investigate ion velocity-space dynamics within the exhaust region of asymmetric magnetopause reconnection using global hybrid-Vlasov simulations. To quantify the complexity of velocity-space structures arising from the mixing of magnetospheric and magnetosheath ion populations, we employ the Hermite transform and Gaussian Mixture …

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Vlasov methods in space physics and astrophysics

Minna Palmroth, Urs Ganse, Yann Pfau‐Kempf, Markus Battarbee et autres

Abstract This paper reviews Vlasov-based numerical methods used to model plasma in space physics and astrophysics. Plasma consists of collectively behaving charged particles that form the major part of baryonic matter in the Universe. Many physical concepts ranging from our own planetary …

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Neural networks as a lossy compression and restart/recovery strategy for high-dimensional plasma simulations

Konstantinos Papadakis, Markku Alho, Juhani Kataja, Ioanna Bouri et autres

High-resolution simulations, such as those of plasma dynamics in the Earth's magnetosphere, generate vast amounts of data that challenge storage and processing capabilities, especially in the Exascale computing era. Managing these data volumes requires innovative solutions that balance compression efficiency with the …

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Performance critical optimizations of 6D hybrid Vlasov simulations

Konstantinos Papadakis

The near-Earth space environment is shaped by the interaction between the solar wind and Earth’s magnetic field, producing plasma phenomena across many different scales. Capturing ion-kinetic effects across global domains requires simulations in six-dimensional (6D) phase space, which place extreme demands on …

The Vlasiator 5.2 ionosphere – coupling a magnetospheric hybrid-Vlasov simulation with a height-integrated ionosphere model

Urs Ganse, Yann Pfau‐Kempf, Hongyang Zhou, Liisa Juusola et autres

Simulations of the coupled ionosphere–magnetosphere system are a key tool to understand geospace and its response to space weather. For the most part, they are based on fluid descriptions of plasma (magnetohydrodynamics, MHD) formalism, coupled to an electrostatic ionosphere. Kinetic approaches to …

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Interplay of Magnetic Reconnection and Current Sheet Kink Instability in the Earth's Magnetotail

Giulia Cozzani, Markku Alho, Ivan Zaitsev, Hongyang Zhou et autres

Abstract Magnetic reconnection and current sheet kink instability often develop concurrently in current sheets, yet their dynamic interplay remains unclear. We investigate their interaction in the magnetotail of a 3D global magnetospheric hybrid‐Vlasov simulation. We identify the instability growth and saturation phase …

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Coalescing MPI Communication in 6D Vlasov Simulations: Solving Ghost Domains in Vlasiator

Markus Battarbee, Urs Ganse, Yann Pfau‐Kempf, Markku Alho et autres

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The Vlasiator 5.2 Ionosphere – Coupling a magnetospheric hybrid-Vlasov simulation with a height-integrated ionosphere model

Urs Ganse, Yann Pfau‐Kempf, Hongyang Zhou, Liisa Juusola et autres

Abstract. Simulations of the coupled ionosphere-magnetosphere system are a key tool to understand geospace and its response to space weather. For the most part, they are based on fluid descriptions of plasma (magnetohydrodynamics, MHD) formalism, coupled an electrostatic ionosphere. Kinetic approaches to …

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Finding reconnection lines and flux rope axes via local coordinates in global ion-kinetic magnetospheric simulations

Markku Alho, Giulia Cozzani, Ivan Zaitsev, Fasil Tesema Kebede et autres

Magnetic reconnection is a crucially important process for energy transfer in plasma physics, the substorm cycle of Earth's magnetosphere and solar flares being prime examples. While 2D models have been widely applied to study reconnection, investigating reconnection in 3D is still in …

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Dayside Pc2 Waves Associated With Flux Transfer Events in a 3D Hybrid‐Vlasov Simulation

Fasil Tesema, Minna Palmroth, Lucile Turc, Hongyang Zhou et autres

Abstract Flux transfer events (FTEs) are transient magnetic flux ropes at Earth's dayside magnetopause formed due to magnetic reconnection. As they move across the magnetopause surface, they can generate disturbances in the ultralow frequency (ULF) range, which then propagate into the magnetosphere. …

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Auroral and energetic electron precipitation in the high-latitude ionosphere: latitudinal variations and local chemical effects in the middle atmosphere

Maxime Grandin, Noora Partamies, Annika Seppälä, Konstantinos Papadakis et autres

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