Transition from global to local control of dayside reconnection from ionospheric‐sourced mass loading. Issue 9 (22nd September 2017)

• Record Type: Journal Article
• Authors: Zhang, B.; Brambles, O. J.; Cassak, P. A.; Ouellette, J. E.; Wiltberger, M.; Lotko, W.; Lyon, J. G.
• Is Part Of: Journal of geophysical research. Volume 122:Issue 9(2017)
• Page Start: 9474
• Page End: 9488
• Publication Date: 2017-09-22
• Subjects: dayside reconnection -- global MHD simulation -- mass loading -- magnetosheath -- ionospheric outflow; Magnetospheric physics -- Periodicals; Space environment -- Periodicals; Cosmic physics -- Periodicals; Planets -- Atmospheres -- Periodicals; Heliosphere (Astrophysics) -- Periodicals; Geophysics -- Periodicals; 523.01
• DOI: 10.1002/2016JA023646
• Languages: English
• ISSNs: 2169-9380

Abstract

Abstract: We have conducted a series of controlled numerical simulations to investigate the response of dayside reconnection to idealized, ionosphere‐sourced mass loading processes to determine whether they affect the integrated dayside reconnection rate. Our simulation results show that the coupled solar wind‐magnetosphere system may exhibit both local and global control behaviors depending on the amount of mass loading. With a small amount of mass loading, the changes in local reconnection rate affects magnetosheath properties only weakly and the geoeffective length in the upstream solar wind is essentially unchanged, resulting in the same integrated dayside reconnection rate. With a large amount of mass loading, however, the magnetosheath properties and the geoeffective length are significantly affected by slowing down the local reconnection rate, resulting in an increase of the magnetic pressure in the magnetosheath, with a significant reduction in the geoeffective length in the upstream solar wind and in the integrated dayside reconnection rate. In this controlled simulation setup, the behavior of dayside reconnection potential is determined by the role of the enhanced magnetic pressure in the magnetospheath due to magnetospheric mass loading. The reconnection potential starts to decrease significantly when the enhanced magnetic pressure alters the thickness of the magnetosheath. Key Points: A transition from global control to local control on dayside reconnection occurs with dayside mass loading Magnetosheath response to changes in local reconnection rate depends on the amount of mass loading The control of dayside reconnection potential is determined by the role of enhanced magnetic pressure in the magnetosheath