Student: Sruti Satyasmita
Školitel: Mgr. Tereza Ďurovcová, Ph.D.
Konzultant: Prof. RNDr. Zdeněk Němeček, DrSc.
Stav práce: volná
Anotace:
The solar wind consists of protons, electrons, and smaller amounts of heavy ions. Two differently streaming proton populations can occur simultaneously – a dominant denser population called the core, and a minor population, the beam. The origin of the proton beam and the mechanisms driving its development in the heliosphere are not yet fully understood. A previous study of Ďurovcová et al. (2021) suggests that proton beam seed is formed near the Sun and then evolves through kinetic processes operating in the solar wind. This study was built on data from the Helios mission operating at radial distances of 0.3 to 1 AU from the Sun. In 2018, the Parker Solar Probe (PSP) was launched and will reach up to 0,046 AU from the Sun at its closest approach. This opened the possibility of studying ion velocity distribution functions (VDFs) near the solar wind source regions, thus the main aim of the thesis will be to study the evolution of ion VDFs in the inner heliosphere. To address this goal, we will develop procedures for determination of the proton beam parameters from the VDFs measured by the SPAN-ion instrument onboard PSP. It allows us to study the development of the proton beam even in the region below the Alfven point where the solar wind is still subsonic and to compare the results with findings from the Helios mission and as well as with measurements at larger distances from the Sun.
Literature:
1) Russell, C.T., Luhmann, J.G. and Strangeway, R.J. (2016) Space Physics: An Introduction. Cambridge: Cambridge University Press.
2) Kallenrode, M.-B. (2013) Space Physics, An Introduction to Plasmas and Particles in the Heliosphere and Magnetospheres, Heidelberg: Springer Berlin.
3) Meyer-Vernet, N. (2007) Basics of the Solar Wind. Cambridge: Cambridge University Press (Cambridge Atmospheric and Space Science Series).
4) Verscharen, D., Klein, K.G. & Maruca, B.A. The multi-scale nature of the solar wind. Living Rev Sol Phys 16, 5 (2019). https://doi.org/10.1007/s41116-019-0021-0
5) Marsch, E. Kinetic Physics of the Solar Corona and Solar Wind. Living Rev. Sol. Phys. 3, 1 (2006). https://doi.org/10.12942/lrsp-2006-1
6) Viall, N.M. and Borovsky, J.E. (2020), Nine Outstanding Questions of Solar Wind Physics. J. Geophys. Res. Space Physics, 125: e2018JA026005. https://doi.org/10.1029/2018JA026005
Journal papers upon recommendation of supervisor