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

FA III – High Latitude Energy Partitioning and Density Implications

Jeff ThayerUniversity of Colorado

Team: Mihail Codrescu, Geoff Crowley,Jeff Forbes, Tim Fuller-Rowell,Delores Knipp, Jiuhou Lei, Art Richmond,Jeff Thayer

Objective: High Latitude Energy Partitioning associated with Solar Wind High Speed Streams and the implications on Thermosphere Density

Oct 17 2008 AES Seminar Thayer 2

Periodic Coronal Holes and Corotating Interaction Regions in the Interplanetary Medium

Yohkoh image-soft X rays


Electrical Energy extracted from the solar wind is largely transferred in the polar regions and converted to other forms of energy

Current Dissipation Particle energy deposition

Geomagnetic Activity


CHAMP Satellite launched in July 2000 at 450 km altitude in a near circular orbit with an inclination of 87.3

Sutton et al., J. Spacecraft and Rockets, 2007

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


Periodic Orbit-Averaged Mass Density Perturbations in 2005

Density - 400km altitude

Solar EUV flux index

Day of Year , 2005


Solar Wind and Geomagnetic Activity

Solar wind speed

Geomagnetic Activity Index


2005 Periodograms – Subharmonics of a Solar Rotation



Solar wind speed


27 days/3


Coronal Holes Distribution

Temmer et al., Sol. Phy., 2007

2005

Solar coronal holes distributed roughly 120 degrees apart in longitude


Wavelet Analysis



Solar wind speed



9-day Periodicities in Thermosphere Density Correlated with Geomagnetic Activity and Felt Globally

9-day Bandpass Filtered Data


Periodograms 2006



Solar wind speed




Study Implications

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.

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.


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.


Declining Phase of the Solar Cycle


Solar Wind Velocity and Kp Index: 2002-2007

2005 2006 2007

2002 2003 2004


GUVI Orbit-Averaged O/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.


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.


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.

a)

b)


V

B

S||

V

B

S||

Examples from DMSP Poynting Flux Calculations

S=(E x Bsat_horizontal)/0 E=-Vsatx BIGRF Bsat_horizontal = Bsat-BAFRL


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


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.

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

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