1. Earth’s Radiation Belt Xi Shao Department of Astronomy, University Of Maryland, College Park, MD 20742

2. Outline History and importance of studying Earth’s radiation belt History and importance of studying Earth’s radiation belt Dynamics of Earth’s radiation belt: Observations Dynamics of Earth’s radiation belt: Observations Origin of Earth’s radiation belt: Geomagnetic Storms and Substorms. Origin of Earth’s radiation belt: Geomagnetic Storms and Substorms. Modeling formation of Earth’s radiation belt. Modeling formation of Earth’s radiation belt. Slot Region formation. Slot Region formation.

3. The Radiation Belt is a energetic torus of energetic charged particles (plasma) around Earth, held in place by Earth's magnetic field Historic discovery in 1958 by the Explorer I in 1958, and Explorer III missions, under Dr.James Van Allen at the University of Iowa. The trapped radiation was first mapped out by Sputnik 3, Explorer IV, Pioneer III and Luna 1. Energetic electrons form two distinct radiation belts, while protons form a single belt. Radiation Belts: The Big Picture Explorer I

4. The Radiation Belts Today: a Dynamic Space Weather Environment Space Weather Applications: Astronauts safety Hardware integrity Mission performance Satellite solar cell panel degradation Single Event Upset (SEU)

5. The Radiation Belts Today: a Dynamic Space Weather Environment

6. Why Trapped? Electron Orbit Proton Orbit

7. NOAA POES Observations-Dynamical View Orbit Altitude: ~ 800 km Inclination: ~ 98 degree Orbit Period: ~100 mins MEPED Detector Energy Channels used in this poster: Proton: >80 MeV (Omni-Detector) Electron: > 300 keV (Omni-Directional flux derived from 2 telescopes) NOAA POES Data obtained from http://poes.ngdc.noaa.gov

8. NOAA POES Satellite Oribit

9. Electron (> 300 keV) Belt Dynamics (1979-1991) Mar. 1989 Mar. 1991 Feb. 1986 Outer Belt Weakens Inner belt Enhanced Apr. 1981 Jul. 1982

10. Electron (> 300 keV) Belt Dynamics (1992-2004) NOAA-15 changes telescope pointing direction and data is still in processing for L < 2. Oct-Nov, 2003 Outer Belt Weakens Inner belt Re-Enhanced

11. Radiation Belt Dynamics and Geomagnetic Storms

12. Proton (> 80 MeV) Belt Dynamics (1979-1991) Mar. 1991 Mar. 1989 Feb. 1986

13. Proton (> 80 MeV) Belt Dynamics (1992-2004) Oct-Nov, 2003

14. Radiation Belt inside the Earth’s Magnetosphere: Its Origin. Earth’s Magnetosphere

15. Modeling Solar Wind Interaction with Earth’s Magnetosphere MHD Equations Solved on a 3D Stretched Spherical Mesh

16. Magnetospheric Storms/Substorms

17. Vortices During 2002-03-29 Event

18. Complex Vortices Structure inside Magnetosphere

19. Magnetospheric Substorm

20. t= 00:-07:-48 t= 00:51:05 t= 01:01:07 t= 00:47:20 t= 00:56:06 t= 01:06:08 Mid-Tail Reconnection

21. Development of Bursty Bulk Flow

22. 1:00 UT Ring Current Development

23. 3D Particle Tracing Code (Full Motion for Protons, and Guiding Center for electrons) Initial Test Particle Distribution 3D Electric-Magnetic field from LFM Global MHD Model of Earth’s Magnetosphere RB energetic particle distribution Physical Modeling of Radiation Belt e p

24. Radiation Belt Electron Dynamics

25. Radiation Belt Protons Dynamics

26. A snapshot of electron location and energy in 3D 10 mins later Initial Configuration of 5keV electrons Energization of Radiation Belt Electrons

27. Formation of Slot Region in Electron Radiation Belt Whistler Waves in the Plasmasphere Slot Region

28. Quick Time Movie

29. Solar Cycle Shifting of Safe-Zone

30. Summary Review History and Importance of Radiation Belt Review History and Importance of Radiation Belt Radiation Belt Structure Radiation Belt Structure Origin of Radiation Belt Origin of Radiation Belt Radiation Belt Slot region Radiation Belt Slot region Safe-zone Solar-Cycle Shifting. Safe-zone Solar-Cycle Shifting.

31. Outstanding science questions Acceleration mechanisms; their relative significance Solar wind-inner magnetosphere coupling Loss mechanisms User needs a Model: Accurate flux models L shell specificity Forensic evaluation Nowcasting