Magnetospheric Reconnection and Geomagnetic Storms: A Personal Perspective

Abstract

At INPE I joined a research group that had started studying astrophysical X-ray sources by performing X-ray measurements with proportional counters onboard rockets in collaboration with a research group from the Space Sciences Laboratory (SSL) of the University of California at Berkeley. Thus, in June 1969 I participated in a rocket campaign of that kind at the rocket launching facility in Natal, located at the equatorial region of Brazil, with the aim of measuring X-rays from the astronomical X-ray source Scorpius X-1. The analysis of the collected observations from that campaign was the topic of my MSc thesis, which was done partly at INPE and completed at the SSL of UC-Berkeley in December of 1969. For my thesis, I benefited strongly by the advice of the SSL-research associate Michael Lampton, who about a decade later was selected as an astronaut to work on NASA missions onboard the space-shuttle carriers. The experience that I gained then by working with X-ray measurements of astrophysical sources I believe was strongly influential for my involvement in experimental research done later at INPE, to measure atmospheric X-rays due to particle precipitation of energetic particles from the inner radiation belt at the South Atlantic Magnetic Anomaly (SAMA), as discussed in Section 4 of this paper.When I started my doctoral program at UC-Berkeley in January of 1970 I moved to the field of space physics at the SSL since at that time in-situ interplanetary and magnetospheric observations started to become available and one could work closely with measurements of space plasmas.

On Short‐Duration Intense and Strongly Geoeffective (ICME)Sheath Magnetic Fields

“…Finally, one could explore in future studies the fundamental differences among largely geoeffective and short‐lived magnetic field structures, especially located in an (ICME)Sheath and leading into an intense auroral activity as that studied by Ohtani (2022), and geoeffective structures with longer durations, located either in the Sheath or in the Driver regions of an ICME leading into intense geomagnetic storm‐activity (e.g., Gonzalez et al., 1994; Gonzalez, 2022). Among those differences, for the former structures one can expect that: (a) externally‐driven aspects of magnetospheric activity should be dominant due to their short‐lived nature (Dai et al., 2020; Ohtani, 2022); (b) their related magnetospheric energization does not lead into a sufficiently strong‐ring current intensification due to the short duration of the driving processes (Ohtani, 2022) and (c) their related reconnection process and associated magnetospheric dynamics need to be regarded and studied as strongly time‐dependent phenomena.…”