Space weather: Solar wind variations and their impact on magnetospheric dynamics

Advisor: Oleksandr Goncharov and Zdenek Nemecek (DSPS FMF CUNI)

Funding: Fully funded (Supported by the grant of the advisors and by the DSPS).



Our society heavily depends on present technologies including global power grids, long pipelines and space based communications that are very sensitive to effects connected with solar activity that bear a common name space weather [1]. Probably the most dangerous events are explosive cases in the solar corona (Coronal Mass Ejections, CMEs) that spew out huge amount of ionized matter into the interplanetary space. When such dense cloud hits the Earth, it deforms the geomagnetic field and induces large currents in power grids that can cause so called blackouts. However, similarly dangerous events can evolve even in a quiet solar wind due to the interaction of solar wind streams with different velocities. The third class of the variations of the geomagnetic field is spontaneous or driven reconfigurations of the field known as geomagnetic storms and substorms. The chain of processes connecting events on the Sun with their response in the Earth environment is long and complicated and thus it is a subject of intensive research for more than four decades [2]. We believe that we know basic mechanisms of mentioned interactions but we are still not able to answer simple questions like why some CME leads to a great magnetosphere response whereas a similar one produces only negligible effects.

Our department deals with different aspects of the space weather from very beginning of space era, participated in numerous space missions (at present in the project Taranis – the French satellite for investigations of the processes in the ionosphere) and collaborates with leading institutions involved in space physics over the world.

We offer experimental studies in following closely related directions: (1) the propagation and evolution of solar wind structures through the interplanetary space [3], (2) modification of their parameters due to interaction each with other and with magnetospheric boundaries [4], (3) formation of magnetospheric boundaries and transfer of the energy and mass to the magnetosphere [5], (4) changes of conditions for the storage of solar wind plasma in the inner magnetosphere [6], and (5) heating of the accumulated plasma to magnetospheric energies and bursty release of the stored mass and energy that result in changes of the geomagnetic field.


[1] Lanzerotti, L. J., Space Weather: Historical and Contemporary Perspectives, Space Sci. Rev., 212 (3-4): 1253-1270, 2017.
[2] Toriumi, S; and Wang, H, Flare-productive active regions, Liv. Rev. Solar Phys., 16: 3, 2019.
[3] Goncharov, O; Koval, A; Šafránková, J; Němeček, Z; Stevens, ML; Szabo, A; Přech, L, Interaction of the interplanetary shock and IMF directional discontinuity in the solar wind, J. Geophys. Res. Space Phys., 123 (5): 3822–3835, 2018.
[4] Urbář, J; Němeček, Z; Šafránková, J; Přech, L, Solar wind proton deceleration in front of the terrestrial bow shock, J. Geophys. Res. Space Phys., 124 (8): 6553–6565, 2019.
[5] Pi, G; Němeček, Z; Šafránková, J; Grygorov, K; Shue, J-H, Formation of the dayside magnetopause and Its boundary layers under the radial IMF, J. Geophys. Res. Space Phys., 123 (5): 3533–3547, 2018.
[6] Nemecek, Z; Safrankova, J; Kruparova, O; Prech, L; Jelinek, K; Dusik, S; Simunek, J; Grygorov, K; Shue, J-H, Analysis of temperature versus density plots and their relation to the LLBL formation under southward and northward IMF orientations, J. Geophys. Res. Space Phys., 120 (5): 3475–3488, 2015.