Welcome to Kun Zhang’s website!
I’m Kun Zhang, a space physicist.
I currently work as an assistant researcher at the Department of Earth, Planetary, and Space Sciences of University of California, Los Angeles. I have a broad research interest in various physical processes in the Earth’s magnetosphere, including the radiation belt dynamics, electron precipitations and dayside interactions. My research involves extensive analysis of satellite data, numerical simulations and plasma theories. I am open to collaborations and discussions, so please feel free to contact me if you are interested in my work.
In my leisure time, I have many hobbies. Most recently, I enjoy gardening on my small patio.
Education
Ph.D. in Aerospace Engineering, University of Colorado, Boulder
Thesis: Findings on the characteristics of radiation belt electrons: precipitation loss, CRAND source and upper flux limit
August 2020
B.S. in Space Science & Technology, Peking University
July 2015
B.S. in Computer Science, Peking University
July 2015
Experience
Assistant Researcher, University of California, Los Angeles
September 2023 – present
Postdoctoral Researcher, Space Science Institute
August 2020 – August 2023
Research Assistant, University of Colorado Boulder
August 2015 – July 2020
My Research
Radiation Belt
The radiation belt is a region filled with high energy electrons and protons in near-Earth space. Radiation belt particles are fatal to space instruments and dangerous to the astronauts. The intensity of radiation belt particles is a balance of acceleration, loss and transport. Understanding the physics underlying these processes is important for the prediction of the radiation belt environment and mitigation of space hazardous events. My research investigates the overall dynamics of the radiation belt electrons by combining measurements at various orbits and locations, such as low Earth orbit (LEO) CubeSats, equatorial radiation belt missions, ground stations, etc. In particular, we evaluate the influence of the precipitation loss of electrons to the radiation belt content. We also study the competing source and loss mechanisms of the radiation belt, such as the Cosmic Ray Albedo Neutron Decay (CRAND) source and the drift loss of the inner belt electrons.
Ion Foreshock
Foreshock is a region upstream of the Earth’s quasi-parallel bow shock and filled with backstreaming particles. The backstreaming ions in the ion foreshock can generate low-frequency large-amplitude waves, called UltraLow Frequency (ULF) waves (a.k.a. foreshock waves or 30-second waves). My research is concerned with the source of the backstreaming foreshock ions, the generation of the foreshock waves and how these upstream perturbations influence the downstream magnetospheric environment. We employ hybrid simulations to reproduce the physical processes in the foreshock and bow shock regions and compare the simulation results with the theories and satellite measurements, in order to obtain an in-depth understanding of the physical processes in these regions. Our research is currently supported by a NSF-funded project on foreshock ions and a NASA-funded project on foreshock waves.
Selected Publications
- Zhang, K., Artemyev, A., Li, X., Zhang, X.-J., Angelopoulos, V., Mei, Y., Xiang, Z., and Grimmich, N. (2024). Nightside electron precipitation patterns as observed by ELFIN and CIRBE CubeSats, Journal of Geophysical Research: Space Physics, 129(11), e2024JA033051.
- Dorfman, S., Zhang, K., Turc, L., Ganse, U., and Palmroth, M. (2023). Probing the foreshock wave boundary with single spacecraft technique, Journal of Geophysical Research: Space Physics, 128(9), e2023JA031724.
- Zhang, K., Li, X., Zhao, H., Xiang, Z., Khoo, L. Y., Zhang, W., Hogan, B., and Temerin, M. A. (2021). Upper limit of electron fluxes observed in the radiation belts, Journal of Geophysical Research: Space Physics, 126, e2020JA028511.
- Zhang, K., Li, X., Xiang, Z., Khoo, L. Y., Zhao, H., Looper, M. D., Temerin, M. A., and Sauvaud, J. A. (2020). Long-term variations of quasi-trapped and trapped electrons in the inner radiation belt observed by DEMETER and SAMPEX, Journal of Geophysical Research: Space Physics, 125, e2020JA028086.
- Zhang, K., Li, X., Zhao, H., Schiller, Q., Khoo, L.-Y., Xiang, Z., Selesnick, R., Temerin, M. A., and Sauvaud, J. A. (2019). Cosmic Ray Albedo Neutron Decay (CRAND) as a Source of Inner Belt Electrons: Energy Spectrum Study, Geophysical Research Letters, 46, 2, 544-552.
- Li, X., Selesnick, R., Schiller, Q., Zhang, K., Zhao, H., Baker, D. N., and Temerin, M. A. (2017). Measurement of electrons from albedo neutron decay and neutron density in near-Earth space, Nature, 552, 382–385.
- Zhang, K., Li, X., Schiller, Q., Gerhardt, D., Zhao, H., and Millan, R. (2017). Detailed characteristics of radiation belt electrons revealed by CSSWE/REPTile measurements: Geomagnetic activity response and precipitation observation, Journal of Geophysical Research: Space Physics, 122, 8, 8434-8445.