1. Periodicities of the Solar Wind, Global Electron Power, and Other Indices in 2005 in HSS Barbara A. Emery (NCAR), Ian G. Richardson (GSFC), David S. Evans (NOAA), and Frederick J. Rich (LL/MIT) MURI, 21-22 October 2008, Boulder CO

2. ABSTRACT We assess the periodicities of the hourly solar wind velocity (Vsw) and the hourly average global electron auroral power (Pe) with Lomb- Scargle analyses in 2005. Other indices such as the 10.7 cm solar flux, total IMF B magnitude (Bt), Kan-Lee merging electric field (Ekl), Kp and Dst are also analyzed. Pe exhibits solar rotational periodicities similar to those for Vsw, where the 9-day periodicity is particularly strong in 2005. This 9-day periodicity is also present in Kp, Dst, Bt, Ekl, in neutral densities ~400 km, and in infrared cooling by [NO] and [CO2] between 100-200 km, but is not found in solar UV radiation or the 10.7 cm solar flux. The periodicities are particularly clear and strong for hours during high-speed solar wind streams (HSS 42%), compared to hours of transients (20%) or slow-speed wind (38%). The periodicities during transients are of large magnitude and chaotic.

3. Estimates of the electron hemispheric power (HPe) into the auroral regions from particle detectors on NOAA and DMSP satellites were inter-calibrated over 29 years and 24 satellites.

4. The electron hemispheric power (HPe) is found in both hemispheres on an hourly basis. The sum of the Northern and Southern hemispheres is the global power (Pe). Uncalibrated HpeCalibrated Hpe

5. Good correspondence between HPe and HPt from POLAR NH Images

6. Best cross-correlation of HPe with Kp and ap

7. HPe and HPi functions of Bz and Vsw

8. 9-d periodicity in Vsw from 3 coronal holes ~120 o apart in solar longitude. Not seen in sunspot area, or related to active regions or to Dst. From Temmer et al. (Solar Phys., 241, 3571-383)

9. 9-d periodicity of HSS also found in Kp and the neutral thermosphere (density at 400 km and infrared cooling by [NO] and [CO 2 ] between 100-200 km), but not in 10.7 cm solar flux. From Thayer et al., (JGR, 2008) and Mlynczak et al., GRL, 2008)

10. Solar Rotational Periodicities in Vsw and Pe 9-d max in 2005

11. Longer Periods in Vsw and Pe

12. Hourly Vsw and Pe in 2005

13. Lomb Periodicities

14. The fraction of time that is spent in each kind of solar wind structure from hourly average Vsw. 2005

15. Vsw and Pe in Solar Structures

16. 10.7 cm Flux and Pe Solar Structure Periodicities

17. Vsw and Dsw Solar Structure Periodicities

18. IMF Bt and Kan-Lee Merging E Field Solar Structure Periodicities

19. Kp and Dst Solar Structure Periodicities

20. CONCLUSIONS Solar rotational 27, 13.5, 9, and 7-day periodicities are usually present in the hourly or daily total Vsw and Pe, with larger magnitudes in descending (D) and minimum (N) SC phases. Longer periodicities (>100 days) are not as well correlated between Vsw and Pe. The 9-day periodicities in Vsw and Pe seen in 2005 are also present in IMF Bt, Kan-Lee merging electric field, Kp, Dst, the neutral thermospheric density and infrared [NO] and [CO 2 ] cooling. The cleanest and often the strongest 9-day periodicities are during HSS hours.

21. References Emery et al. (2008), Seasonal, Kp, solar wind, and solar flux variations in long-term single-pass satellite estimates of electron and ion aurora hemispheric power, J. Geophys. Res., 113, A06311, doi:10.1029/2007JA012866. Emery, Richardson, Evans, and Rich (2008), Solar wind structure sources and periodicities of global electron hemispheric power over three solar cycles, J. Atmos. Terr. Phys., HSS Special Issue, accepted Aug 2008. (http://dx.doi.org/10.1016/j.jastp.2008.08.005) Mlynczak et al. (2008), Solar-terrestrial coupling evidenced by periodic behavior in geomagnetic indexes and the infrared energy budget of the thermosphere, Geophys. Res. Lett., 35, L05808, doi:10.1029/2007GL032620. Temmer et al. (2007), Periodic appearance of coronal holes and the related variation of solar wind parameters, Solar Phys., 241, 371-383. Thayer et al. (2008), Thermospheric density oscillations due to periodic solar wind high speed streams, J. Geophys. Res., 113, A06307, doi:10.1029/2008JA013190.