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Ionosphere Climate Studied by F3 / COSMIC Constellation

Ionosphere Climate Studied by F3 / COSMIC Constellation C. H. Liu Academia Sinica. In Collaboration with Tulasi Ram, C.H. Lin and S.Y. Su.

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Ionosphere Climate Studied by F3 / COSMIC Constellation

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  1. Ionosphere Climate Studied by F3 / COSMIC Constellation C. H. Liu Academia Sinica In Collaboration with Tulasi Ram, C.H. Lin and S.Y. Su

  2. The Ionospheric Environment is affected by Solar-Terrestrial Connections from above and Atmospheric Dynamics from below. Understanding of the Variations in this region, the Climate and Weather of the Ionosphere, is Important since a large part of Human Activities in Space occurs in this region.

  3. COSMIC – Constellation Observing System for Meteorology, Ionosphere and Climate A constellation of six micro satellites - 800 km altitude - 30o of separation in longitude - 72o inclination GPS Occultation eXperiment (GOX) - ~ 2000 Ne(h) profiles per day - Spatially uniform Academia Sinica, Taipei, Taiwan

  4. FORMOSAT 3 / COSMIC Has Global Coverage with Good Height Resolution Suitable to Study Global Phenomena

  5. Equatorial Ionosphere Modified by the Atmospheric Tides Coupling from Below • 9-Day Oscillation in the Ionosphere A New Solar-Terrestrial Connection

  6. By Binning the 30 day Ionospheric Soundings (excluding magnetic disturbed days) in Every 2(1)-Hour Interval and Taking Median Value of the Soundings located in the 5 degree by 5 degree grid, a Global Electron Density Map for the 30 day Period Is Constructed with good Height Resolution at a Given Local Time.

  7. Equatorial Plasma Fountain & The Equatorial Ionization Anomaly (EIA) Low-Latitude Ionosphere is dominated by the electrodynamics Courtesy of David Anderson

  8. Observe the northern hemisphere only Newly discovered ionospheric feature at low-latitude Recent discovered four-peaked longitudinal structure produced by atmospheric tides : First reported by Sagawa et al. [2005] and Immel et al. [2006] • E3 Nonmigrating tide produced by the latent heat excited by tropospheric water vapors • Modulating the E-region dynamo and the plasma fountain IMAGE FUV observation E3 non-migrating tide modeled by global scale wave model (GSWM) [Hagan and Forbes, JGR, 2002]

  9. Recent discoveredlongitudinal structure produced by atmospheric tides : FORMOSAT-3/COSMIC electron content observations: 2000~2200 LT

  10. The Four-Peaked Longitudinal structure in EIA is caused by the Eastward Wave Number Three (E 3) Nonmigrating Tide Excited by Latent Heat Release in the Troposphere. E 3 shows Stronger Amplitude in Winds and Temperature at the Four Longitudinal Locations. The Stronger Winds Strengthen the E-Region Dynamo generated daytime Eastward Electric Field which in turn mapped to the F-region Produces a stronger Equatorial Plasma Fountain.

  11. 3-D structures at 20:00~22:00 LT Questions: 1. In what altitude does the structure becomes prominent? 2. Does the structure occur in daytime or nighttime only or both? 3. What is the diurnal variation of the structure? Lin et al., GRL, 2007

  12. Diurnal variations of the wave-4 structure during Sep.-Oct. 2006 Starting at 08-10 LT, strongest at 14-16LT, subsiding after 22LT Lin et al., JGR, 2007

  13. E×B drifts from empirical model: 19 LT 10 16 Scherliess and Fejer, JGR, 1999 • 10LT: • Four-peaked structure formed. • 16LT: • Four-peaked structure become less prominent. • 19 LT: • Possibly connected to re-appearance of four-peaked structure at 20LT. • Suggesting the E3 tidal effect act as a perturbation component to the regular upward E×B drift.

  14. Jul-Aug 2007 Northern Summer Sep-Oct 2007 Equinox Nov-Dec 2007 Northern Winter

  15. A 9-Day Recurring Fast Streams in Solar Wind due to a Triad of Solar Coronal Holes distributed roughly 120 degree apart in Longitude Cause Periodic Variations in Thermosphere Neutral Density, Temperature and Ionosphere Ionization Distributions. (Lei et al. 2008a, b, c; Thayer et al. 2008; Crowley et al. 2008)

  16. The daytime (0600 to 1800 LT) electron density profiles in each day are zonally (longitudinally) averaged into 16 latitudinal bins from -80 to +80 degrees geographic latitudes and 40 altitudinal bins from 100 to 500 km

  17. 9-day period Daily zonal mean electron density from COSMIC 2007 – 2008 (Solar Minimum) 400 km altitude Academia Sinica, Taipei, Taiwan

  18. Zonally mean Ele. density Zonally mean Ele. density Zonally mean Ele. density Spectral peaks at 27, 13.5, 9, 7 and 5-day periods Sub-harmonic Solar Rotation Spectral peaks at 27, 13.5, 9, 7 and 5-day periods Sub-harmonic Solar Rotation Spectral peaks at 27, 13.5, 9, 7 and 5-day periods Sub-harmonic Solar Rotation Academia Sinica, Taipei, Taiwan

  19. Absent A comparison of spectra of Helio-Geophysical Parameters Mg-II Index 7 9 13 5 27

  20. HT – Scale Height More prominent at high-lat hmF2 – F2 layer peak height almost uniform globally NmF2 – F2 layer peak density opposite at high and low latitudes Academia Sinica, Taipei, Taiwan

  21. Academia Sinica, Taipei, Taiwan

  22. Academia Sinica, Taipei, Taiwan

  23. 9-day periodic oscillations in 2008 350 km Day Time Night Time

  24. Further Studies Other Multi-day Oscillations in the Ionosphere, Mechanisms, Impacts on Space Climate and Weather

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