Analysis of the Interaction between Solar Wind and Earth’s Magnetosphere and Its Effects on Sudden Impulses

The Sun continuously emits a plasma known as the solar wind, which propagates through interplanetary space. This plasma interacts with Earth’s magnetic field (CMT), forming the magnetosphere, a region where different types of plasma and currents coexist. When there is a variation in solar wind pressure, the magnetosphere undergoes compression or decompression, causing changes in the Chapman-Ferraro current at the magnetopause. These changes generate a magnetic field that is perceived almost instantly by magnetometers installed on satellites or at ground observatories. Compression leads to a sudden increase in the H component of the geomagnetic field, known as a Sudden Impulse (SI). SIs, when measured on the ground, exhibit different morphologies and amplitudes, as local ionospheric currents also influence them. Thus, this paper reviews the main theories on solar wind-magnetosphere coupling, considering models and experimental data. It also explores the diversity in the morphology of ground-measured SIs. The results highlight that, although the physical foundations of the coupling between the solar wind and the magnetosphere are well-established both theoretically and experimentally, some points remain under discussion, such as the influence of the South Atlantic Magnetic Anomaly on SIs.

Keywords
Solar Wind-magnetosphere Coupling; Geomagnetic Storms; Sudden Impulses