Magnetospheric vortices and their global effect after a solar wind dynamic pressure decrease. Issue 2 (2nd February 2016)

• Record Type: Journal Article
• Authors: Zhao, H. Y.; Shen, X. C.; Tang, B. B.; Tian, A. M.; Shi, Q. Q.; Weygand, J. M.; Yao, Z. H.; Zong, Q.‐G.; Fu, S. Y.; Yao, S. T.; Xiao, T.; Pu, Z. Y.
• Is Part Of: Journal of geophysical research. Volume 121:Issue 2(2016:Feb.)
• Page Start: 1071
• Page End: 1077
• Publication Date: 2016-02-02
• Subjects: negative solar wind dynamic pressure pulse -- magnetosphere vortex -- field‐aligned current; Magnetospheric physics -- Periodicals; Space environment -- Periodicals; Cosmic physics -- Periodicals; Planets -- Atmospheres -- Periodicals; Heliosphere (Astrophysics) -- Periodicals; Geophysics -- Periodicals; 523.01
• DOI: 10.1002/2015JA021646
• Languages: English
• ISSNs: 2169-9380

Abstract

Abstract: Using multipoint data from three Time History of Events and Macroscale Interactions during Substorms (THEMIS) satellites, we report a magnetospheric flow vortex driven by a negative solar wind dynamic pressure pulse. The observed vortex rotated in a direction opposite to that associated with positive solar wind dynamic pressure pulses. The vortex was moving tailward, as confirmed by a global magnetohydrodynamics (MHD) simulation. In addition, the equivalent ionospheric currents (EICs) deduced from ground magnetometer station data reveal that a current vortex in the ionosphere near the foot point of the satellites has a rotation sense consistent with that observed in the magnetosphere. The field‐aligned current (FAC) density estimated from three THEMIS satellites is about 0.15 nA/m 2, and the total FAC of the vortex is about 1.5–3 × 10 5 A, on the order of the total FAC in a pseudobreakup, but less than the total FAC in most moderate substorms, 10 6 A. Key Points: Negative solar wind pressure pulse driven magnetospheric vortex was observed This tailward moving vortex was confirmed by simulation and ground data The vortex related FAC is the order of the total FAC in a pseudobreakup