FA III – High Latitude Energy Partitioning and Density Implications Jeff Thayer University of Colorado

1. FA III – High Latitude Energy Partitioning and Density ImplicationsJeff ThayerUniversity of Colorado Team: Mihail Codrescu, Geoff Crowley,Jeff Forbes, Tim Fuller-Rowell,Delores Knipp, Jiuhou Lei, Art Richmond,Jeff ThayerObjective:High Latitude Energy Partitioning associated with Solar Wind High Speed Streams and the implications on Thermosphere Density

2. Periodic Coronal Holes and Corotating Interaction Regions in the Interplanetary Medium Yohkoh image-soft X rays

3. Electrical Energy extracted from the solar wind is largely transferred in the polar regions and converted to other forms of energy Geomagnetic Activity Current Dissipation Particle energy deposition

4. CHAMP Satellite launched in July 2000 at 450 km altitude in a near circular orbit with an inclination of 87.3 The physical parameters of the CHAMP satellite are: • Total Mass 522 kg • Height 0.750 m • Length (with 4.044 m Boom) 8.333 m • Width 1.621 m • Area to Mass Ratio 0.00138 m2kg-1 Sutton, PhD Thesis, 2008 Sutton et al., J. Spacecraft and Rockets, 2007

5. Periodic Orbit-Averaged Mass Density Perturbations in 2005 Density - 400km altitude Solar EUV flux index Day of Year , 2005

6. Solar Wind and Geomagnetic Activity Solar wind speed Geomagnetic Activity Index

7. 27 days/3 2005 Periodograms – Subharmonics of a Solar Rotation Density - 400km altitude Solar EUV flux index Solar wind speed Geomagnetic Activity Index

8. Coronal Holes Distribution 2005 Temmer et al., Sol. Phy., 2007 Solar coronal holes distributed roughly 120 degrees apart in longitude

9. Wavelet Analysis Density - 400km altitude Solar EUV flux index Solar wind speed Geomagnetic Activity Index

10. 9-day Periodicities in Thermosphere Density Correlated with Geomagnetic Activity and Felt Globally 9-day Bandpass Filtered Data

11. Periodograms 2006 Solar EUV flux index Solar wind speed Geomagnetic Activity Index Density - 400km altitude Density - 400km altitude

12. Study Implications Lei, J., J. P. Thayer, J. M. Forbes, E. K. Sutton, and R. S. Nerem (2008), Rotating solar coronal holes and periodic modulation of the upper atmosphere, Geophys. Res. Lett., 35, L10109, doi:10.1029/2008GL033875. Thayer, J. P., J. Lei, J. M. Forbes, E. K. Sutton, and R. S. Nerem (2008), Thermospheric density oscillations due to periodic solar wind high-speed streams, J. Geophys. Res., 113, A06307, doi:10.1029/2008JA013190. • A solar-terrestrial connection between rotating solar coronal holes, periodic solar wind variation, and oscillations of thermospheric density has been discovered on multi-day periodicities. • The lack of EUV flux variability at 5, 7 and 9 days allows for geomagnetic activity effects to be isolated from EUV flux variations • The periodic connection suggests an element of predictability for satellite drag analysis • 30-50% perturbations in density are modest compared to major magnetic storms but their much higher occurrence frequency and characteristic long recovery time may lead to a cumulative effect on the state of the thermosphere and satellite drag • The density variations should also be observed in other properties of the thermosphere and ionosphere and on other planetary bodies.

13. Follow-on Studies, so far… • Lei, J., J. P. Thayer, J. M. Forbes, E. K. Sutton, and R. S. Nerem, M. Temmer, A. M. Veronig, Thermospheric density response to high-speed solar wind streams during the declining phase of solar cycle 23, in press, J. Geophys. Res., 2008. • Lei, J., J. P. Thayer, J. M. Forbes, Q. Wu, C. She, W. Wan, W. Wang, Ionosphere response to solar wind high speed streams, accepted, GRL, June 2008. • Crowley, G., A. Reynolds, J. P. Thayer, J. Lei, L.J. Paxton, A.B. Christensen, Y. Zhang, R.R. Meier, D.J. Strickland, Periodic Modulations in Thermospheric Composition by Solar Wind High Speed Streams, accepted, GRL October 2008. • Palo, S. A., J. P. Thayer, J. Lei, L. Chang, Lower thermosphere temperature response to solar wind high speed streams, in preparation.

14. Declining Phase of the Solar Cycle

15. Solar Wind Velocity and Kp Index: 2002-2007 2003 2004 2002 2006 2007 2005

16. GUVI Orbit-Averaged SO/N2 ratio for 2005 FIGURE 1: F10.7 (units of 10-22 Wm-2 Hz-1), solar wind velocity (SwVel), Kp geomagnetic index, and GUVI orbit-averaged ΣO/ N2 ratio for 2005.

17. Lomb-Scargle Periodogram FIGURE 2: Lomb-Scargle periodogram of (a) F10.7 (units of 10-22 Wm-2 Hz-1), (b) solar wind velocity (SwVel), (c) Kp geomagnetic index, (d) GUVI orbit-averaged ΣO/ N2 ratio for 2005 including all latitudes, (e) same as (d) but limited to latitude range +/- 60 degrees.

18. a) b) GUVI O/N2 as a Function of Latitude and Day FIGURE 3: (a) raw GUVI ΣO/ N2 ratio as a function of latitude and time for the first 100 days of 2005, with Kp superposed (black line); (b) Residuals 10° latitude bands after bandpass filtering and removal of the of 11-day running mean, expressed as a percentage of the running mean values. Broken line shows Kp after similar bandpass filtering.

19. Examples from DMSP Poynting Flux Calculations S=(E x Bsat_horizontal)/0E=-Vsatx BIGRF Bsat_horizontal = Bsat-BAFRL V B S|| V B S||

20. Preliminary Results • DMSP Poynting flux values generally twice those of Weimer model • Numerous instances of localized heating spikes in dayside high latitude regions • Stormtime, orbit-integrated Poynting flux usually maximizes during main phase • Extreme localized Poynting flux enhancements with large in-the-ecliptic IMF values • Consistent with unusual density variations of 15-16 May 2005

21. TIMEGCM Simulations of Joule Heating and Thermosphere Density • Figure 1: The global mean density variation computed from TIMEGCM for about 18 days in November 2004 (black line), together with the Joule heating derived from TIMEGCM (red line). A major storm on days 313-316, 2004 produced large density enhancements.