[P-EM12] [EE] Space Weather, Space Climate, VarSITI

[PEM12-37] Geomagnetic storms of March 17, 2013 and 2015: GPS phase scintillation and auroral electrojet currents

*Paul Prikryl^1,2、Reza Ghoddousi-Fard³、Ari Viljanen⁴、James M Weygand⁵、Bharat S R Kunduri⁶、Evan G Thomas⁷、J Michael Ruohoniemi⁶、Martin Connors⁸、Donald W Danskin²、P T Jayachandran¹、Knut S Jacobsen⁹、Yngvild L Andalsvik⁹、Tibor Durgonics¹⁰、Kjellmar Oksavik^11,12、Yongliang Zhang¹³、Emma Spanswick¹⁴、V Sreeja¹⁵、Marcio Aquino¹⁵ (1.Physics Department, University of New Brunswick, Fredericton, NB, Canada、2.Geomagnetic Laboratory, Natural Resources Canada, Ottawa, ON, Canada、3.Canadian Geodetic Survey, Natural Resources Canada, Ottawa, ON, Canada、4.Finnish Meteorological Institute, Helsinki, Finland、5.Institute of Geophysics and Planetary Physics, University of California, Los Angeles, CA, USA、6.Bradley Dept. of Electrical and Computer Engineering, Virginia Tech, Blacksburg, VA, USA、7.Thayer School of Engineering, Dartmouth College, Hanover, NH, USA、8.Athabasca University, Edmonton, Alberta, Canada、9.Norwegian Mapping Authority, Hønefoss, Norway、10.Technical University of Denmark, National Space Institute, Kongens Lyngby, Denmark、11.Birkeland Centre for Space Science, Department of Physics and Technology, University of Bergen, Bergen, Norway、12.The University Centre in Svalbard, Longyearbyen, Norway、13.Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA、14.Department of Physics and Astronomy, University of Calgary, AB, Canada、15.Nottingham Geospatial Institute, University of Nottingham, Nottingham, UK)

キーワード：Polar and auroral ionosphere, Ionospheric irregularities, Ionospheric currents, Radio wave propagation, Space and satellite communication, Space weather, Impacts on technological systems

Interplanetary coronal mass ejections compounded by high-speed plasma streams from coronal holes caused two intense geomagnetic storms on March 17-18, 2013 and 2015 during the current solar cycle. Using arrays of ground-based instruments including GPS receivers, HF radars, ionosondes, riometers, all-sky imagers and magnetometers, GPS phase scintillation is studied in the context of solar wind coupling to the magnetosphere-ionosphere system comparing the two storms. The phase scintillation index is computed for signals sampled at a rate of 50 Hz by specialized GPS scintillation receivers. It is supplemented by the phase scintillation proxy index obtained from geodetic-quality GPS data sampled at 1 Hz. We examine the relation between the scintillation and auroral electrojet currents observed by arrays of ground-based magnetometers as well as energetic particle precipitation observed by the DMSP satellites. Equivalent ionospheric currents are obtained from ground magnetometer data using the spherical elementary currents systems technique that has been applied over the ground magnetometer networks in North America and northern Europe. For both storms, preliminary results indicate that the GPS phase scintillation is mapped to strong westward electrojet and to the poleward edge of the eastward electrojet. GPS phase scintillation is mostly absent or low in the auroral zone when the electrojets are weak.