Download
aurora n.
Skip this Video
Loading SlideShow in 5 Seconds..
Aurora PowerPoint Presentation

Aurora

196 Views Download Presentation
Download Presentation

Aurora

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. Aurora Stan Solomon High Altitude Observatory National Center for Atmospheric Research Summer Colloquium on Space Weather • NCAR Advanced Studies Program • 7 June 2005

  2. Is the Aurora Borealis similar to the Aurora Australis?

  3. Reconnection in the Magnetotail

  4. Coupled Magnetosphere-Ionosphere-Thermosphere Model

  5. Energetic Particles from the Magnetosphere

  6. Motion of Charged Particles Along a Magnetic Field Line

  7. Transport of Auroral Electrons in the Upper Atmosphere

  8. Penetration Depth of Auroral Electrons Depends on Energy

  9. Thermosphere and Ionosphere Composition

  10. Auroral Collisional Processes Electron Impact Ionization

  11. Ion Recombination Processes

  12. Simplified Schematic of Ion-Neutral Chemistry

  13. Examples of Auroral Emission Processes e* + N2 2e* + N2+(B2Su+) N2+(B2Su+)  N2+(X1Sg+) + hn (1N bands) e* + N2 e* + N2(B3Pg) N2(B3Pg)  N2(X1Sg+) + hn (1P bands) e* + N2 e* + N2(A3Su+) N2 (A3Su+)  N2(X1Sg+) + hn (VK bands) N2 (A3Su+) + O(3P)  N2(X1Sg+) + O(1S) O(1S)  O(3P) + hn (5577Å) e* + O(3P)  e* + O(1S) O(1S)  O(3P) + hn (5577Å) t~1s e* + O(3P)  e* + O(1D) O(1D)  O(3P) + hn (6300Å) O2+ + e-  O + O(1D) O(1D)  O(3P) + hn (6300Å) t~100s O(1D) + N2  O(3P) + N2 e* + N2  e* + N(4S) + N(2D) N(2D)  N(4S) + hn (5200Å) NO+ + e-  O + N(2D) N(2D)  N(4S) + hn (5200Å) t~1e5s N(2D) + O  N(4S) + O

  14. Question for Discussion The aurora has been compared to a cathode-ray tube (e.g., TV set, computer monitor, etc.) Is this a good analogy?

  15. Photo Credits Tom Eklund Dave Fritts NASA / Univ. Iowa NASA / UC Berkeley NASA STS Stan Solomon