Multi-point Measurements of Energetic Particle Deep Penetration into the Low L Region

Zhao, Hong

Multi-point Measurements of Energetic Particle Deep Penetration into the Low L Region

Tuesday, 11 July 2017: 11:20

Furong Room (Cynn Hotel)

Hong Zhao¹, Daniel N. Baker², Sam Califf², Xinlin Li², Allison N Jaynes³, Trevor W Leonard⁴, Shrikanth G Kanekal⁵, J Bernard Blake⁶, Joseph F. Fennell⁷, Seth G Claudepierre⁶, Drew L Turner⁸, Geoffrey D Reeves⁹ and Harlan E. Spence⁷, (1)University of Colorado at Boulder, LASP and Aerospace Engineering Sciences, Boulder, CO, United States, (2)University of Colorado at Boulder, Boulder, CO, United States, (3)University of Colorado at Boulder, LASP, Boulder, CO, United States, (4)Laboratory for Atmospheric and Space Physics, Boulder, CO, United States, (5)NASA Goddard Space Flight Center, Greenbelt, MD, United States, (6)Aerospace Corporation Santa Monica, Santa Monica, CA, United States, (7)University of New Hampshire Main Campus, Space Science Center, Durham, NH, United States, (8)Aerospace Corporation El Segundo, El Segundo, CA, United States, (9)Los Alamos National Laboratory, Los Alamos, NM, United States

Abstract:

Using multi-point measurements from multiple satellites, a penetration event of energetic protons and electrons into low L region is studied. Timing and magnetic local time (MLT)-dependent pattern of energetic particle deep penetration are unveiled for the first time and underlying physical processes are examined. During this event, both proton and electron penetration are MLT-asymmetric. The observed MLT-dependent feature of proton penetration is consistent with convection of plasma sheet protons, suggesting enhanced convection during geomagnetic active times to be the cause of energetic proton deep penetration. The observed MLT-dependent feature of 10s – 100s of keV electron penetration, which is completely different from protons, cannot be well explained by inward radial diffusion, convection of plasma sheet electrons, or enhanced convection electric field. It suggests that underlying physical mechanism responsible for energetic electron deep penetration, which is very important for fully understanding energetic electron dynamics in low L region, could be MLT-localized.