Solar Wind Energy Input: The Primary Control Factor of Magnetotail Reconnection Site. Issue 8 (11th August 2022)

• Record Type: Journal Article
• Authors: Nagai, Tsugunobu; Shinohara, Iku
• Is Part Of: Journal of geophysical research. Volume 127:Issue 8(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-08-11
• Subjects: magnetic reconnection -- solar wind -- plasma sheet -- substorm -- magnetotail -- current wedge; Magnetospheric physics -- Periodicals; Space environment -- Periodicals; Cosmic physics -- Periodicals; Planets -- Atmospheres -- Periodicals; Heliosphere (Astrophysics) -- Periodicals; Geophysics -- Periodicals; 523.01
• DOI: 10.1029/2022JA030653
• Languages: English
• ISSNs: 2169-9380

Abstract

Abstract: In this paper, we examine the solar wind energy input (expressed by −Vx × Bs, where Vx is the x component of the solar wind velocity and Bs is the southward component of the interplanetary magnetic field IMF Bz) for an onset of magnetic reconnection in the near‐Earth magnetotail. There are 41 events in which in situ observations of magnetic reconnection were made by Geotail. Magnetic reconnection in the postmidnight (premidnight) sector of the plasma sheet occurred under strong (weak) solar wind energy input conditions. Furthermore, we study temporal variations in the solar wind energy input with two different approaches using ground magnetic field observations and proton injections at geosynchronous altitude. These two analyses confirmed the preference of the postmidnight sector for the onset of magnetic reconnection under the strong solar wind energy input conditions. It is also found that the medium and weak solar wind energy input may move the onset location to earlier magnetic local times. The onset location of magnetic reconnection in the near‐Earth magnetotail is controlled by the solar wind energy input through the global magnetospheric dynamics during the loading period. Key Points: The strong solar wind energy input produces favorable conditions for an onset of magnetic reconnection in the postmidnight sector of the plasma sheet The medium and weak solar wind energy input forms favorable conditions for the onset of magnetic reconnection in earlier magnetic local times