THEMIS Update and a Review of the Science Behind Magnetometer Signatures By Laura Peticolas 2. Outline 3. Satellites Update 4. Ground-based Update 5. Earth’s magnetic fields 6. Magnetic Field Strength 7. Coordinate Systems 8. Geomagnetic (GEONS) 9. Compass-type (HDZ) 10. The GEONS Data 11. Earth’s Magnetic Field 12. Different Latitudes 13. Magnetosphere 14. Magnetosphere currents 15. Solar Wind (SW) 16. Effects of Ring Current on the Mag Data 17. Auroral Currents 18. Magnetic signatures of auroral substorms 19. Kp Index 20. Kp Index = 1 21. Kp Index = 7 22. Space Weather Effects 23. Storm and Substorms 24. THEMIS will determine which competing model is correct 25. Daytime (Sq) Currents 26. Ionosphere Effects     The GEONS Data Ø X: the strength in nT of the magnetic field in the direction of magnetic north pole Ø Y: the strength in nT of the magnetic field in the magnetic east direction Ø Z: the strength in nT of the magnetic field pointing down Daylight time: April 4-Oct. 31. 2005 Slide 10 of 26