Date and Time: 2026/07/06, 15:00
Speaker: Miroslav Hanzelka; Research Scientist at the Department of Space Physics, Institute of Atmospheric Physics of the Czech Academy of Sciences (IAP CAS, Prague)
Abstract: In this talk I will present a brief overview of my recent publications on the topic of nonlinear interactions of electrons with electromagnetic ion cyclotron (EMIC) waves and chorus waves. Opening with a quick review of cyclotron-resonant interactions, we will look at the role of phase trapping and anomalous trapping in first- and second-order transport and we will discuss their effects on evolution of phase space density near the loss cone and on the related atmospheric loss. We will also touch upon the weak fractional resonances and consider their impact on sub-MeV electron precipitation by quasiparallel EMIC waves.
The second part of the talk will focus on chorus waves, starting with a description of the differences between whistler-electron and EMIC-electron interactions, highlighting the ultrarelativistic acceleration. Using test-particle simulations and phase space mapping, we will observe how adding realistic properties to chorus elements (subpacket modulations with phase jumps and broader wave normal distributions) leads to suppression of coherent scattering and to a faster phase space mixing, supporting the use of stochastic models. We will also explore the role of wave packet modulations transverse to the field line, revealing them to be an extremely efficient disruptor of coherent interactions, albeit only at multi-MeV electron energies.
Throughout this talk, we will take brief excursions to better understand some more involved concepts in stochastic transport, spatio-temporal wave structures, and other intriguing topics.
About the speaker: Miroslav (Mirek) Hanzelka received his PhD in Theoretical Physics and Astrophysics from the Charles University in Prague and has been working on simulations and theory of wave propagation and wave-particle interactions in magnetospheres since his undergraduate studies. He studied under Prof. Santolík at IAP, worked under Prof. W. Li as postdoctoral associate at the Boston University, and worked with Prof. Y. Shprits and Dr. D. Wang as Humboldt postdoctoral fellow at GFZ in Germany.
Currently, he is working as research scientist at IAP in Prague, focusing on understanding of long-term effects of nonlinear scattering on electron fluxes in the radiation belts. He is a leader of an International ISSI team working on modelling non-diffusive processes in the inner magnetosphere and a member of a working group under the ESA NEOMI programme, developing new spacecraft mission ideas related to particle precipitation. He was awarded IAGA Early Career Award and four URSI Young Scientist Awards for his plasma wave research. Recently, he received the Marie Curie Global Fellowship (starting 2027) to work at the University of Michigan on incorporation of nonlinear interactions into radiation belt models.
