EGU23-3306, updated on 09 Jan 2024
https://doi.org/10.5194/egusphere-egu23-3306
EGU General Assembly 2023
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

Can Throat Auroras Create Polar Cap Patches？

Duan Zhang1, Qinghe Zhang2, Kjellmar Oksavik3, Tong Xu4, Zanyang Xing5, Larry Lyons6, Desheng Han7, Hongbo Zhang8, Yuzhang Ma9, Zejun Hu10, Jianjun Liu11, Yong Wang12, and Xiangyu Wang13
Duan Zhang et al.
  • 1Shandong University, School of space science and physics, Space science, China (202020937@mail.sdu.edu.cn)
  • 2Shandong University, School of space science and physics, Space science, China (zhangqinghe@sdu.edu.cn)
  • 3Birkeland Centre for Space Sciences, Department of Physics and Technology, University of Bergen, Bergen, Norway (Kjellmar.Oksavik@uib.no))
  • 4National Key Laboratory of Electromagnetic Environment, China Research Institute of Radiowave Propagation, Qingdao, China (xutong1104@126.com))
  • 5Shandong University, School of space science and physics, Space science, China (xingzanyang@sdu.edu.cn)
  • 6Department of Atmospheric and Oceanic Sciences, University of California, CA, Los Angeles, United States (larry@atmos.ucla.edu)
  • 7State Key Laboratory of Marine Geology, School of Ocean and Earth Science, Tongji University, Shanghai, China (handesheng@tongji.edu.cn)
  • 8National Key Laboratory of Electromagnetic Environment, China Research Institute of Radiowave Propagation, Qingdao, China (ssrs_nklee@163.com)
  • 9Shandong University, School of space science and physics, Space science, China (myz0103@sina.com)
  • 10Polar Research Institute of China, Shanghai, China (huzejun@pric.org.cn)
  • 11Polar Research Institute of China, Shanghai, China (liujianjun@pric.org.cn)
  • 12Shandong University, School of space science and physics, Space science, China (wangyong180@163.com)
  • 13Shandong University, School of space science and physics, Space science, China (wangxy_ddesmond@qq.com)

Throat auroras and polar cap patches are common phenomena in the polar ionosphere. An observation campaign was organized, with all-sky imagers at Yellow River Station in Ny-Ålesund in Svalbard, the EISCAT Svalbard Radar, and coordinated low-altitude spacecraft observations. During periods of radial interplanetary magnetic field (IMF), observations showed that poleward moving throat auroras were linked to poleward moving ionization patches. Throat auroras are produced by soft-electron precipitation associated with dayside magnetic reconnection. The red line intensity of throat auroras is found to be correlated with dayside reconnection events. Dense plasma from lower latitudes was transported poleward by enhanced convection associated with the throat auroras to form electron density patches. This is potentially a new patch formation mechanism that is associated with throat auroras and magnetic reconnection for radial IMF. Moreover, the patches were found to E × B drift in the anti-sunward direction.

How to cite: Zhang, D., Zhang, Q., Oksavik, K., Xu, T., Xing, Z., Lyons, L., Han, D., Zhang, H., Ma, Y., Hu, Z., Liu, J., Wang, Y., and Wang, X.: Can Throat Auroras Create Polar Cap Patches？, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3306, https://doi.org/10.5194/egusphere-egu23-3306, 2023.