Coalescence of magnetic flux ropes observed in the tailward high‐speed flows. Issue 11 (12th November 2016)

• Record Type: Journal Article
• Authors: Zhao, Yan; Wang, Rongsheng; Lu, Quanming; Du, Aimin; Yao, Zhonghua; Wu, Mingyu
• Is Part Of: Journal of geophysical research. Volume 121:Issue 11(2016:Nov.)
• Page Start: 10, 898
• Page End: 10, 909
• Publication Date: 2016-11-12
• Subjects: magnetic flux ropes -- magnetotail -- coalescence of flux ropes -- magnetic reconnection; Magnetospheric physics -- Periodicals; Space environment -- Periodicals; Cosmic physics -- Periodicals; Planets -- Atmospheres -- Periodicals; Heliosphere (Astrophysics) -- Periodicals; Geophysics -- Periodicals; 523.01
• DOI: 10.1002/2016JA023526
• Languages: English
• ISSNs: 2169-9380

Abstract

Abstract: We report a tailward high‐speed flow event observed by Cluster during 0203:00UT–0205:30UT on 20 September 2003. Within the flows, a series of three bipolar B z signatures were observed. The first and third bipolar B z signatures are identified as magnetic flux ropes, while the middle one is found to result from the collision of the two flux ropes. A vertical thin current layer was embedded in the center of the middle bipolar B z signature. Combining the plasma, electric field, and wave data around the thin current layer, we conclude that the two magnetic flux ropes were coalescing. The observations indicate that coalescence of magnetic flux ropes can happen in the regions away from reconnection site and can produce energetic electrons and waves. A basic criterion for identifying the coalescence in the magnetotail is proposed also. Key Points: Two magnetic flux ropes were observed in tailward high‐speed flows The two flux ropes were confirmed to be coalescing A basic criterion for identifying the coalescence is provided