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THEMIS - ISR Support

THEMIS - ISR Support. H. Vo, Arecibo Observatory. The geomagnetic context of NSF UAF ISR. G. M. M. G. Nighttime. Daytime. ISR Locations. With AMISR, the UAF ISR gives E from pole to equator. Poker Flat ISR will completed by 2006 Resolute ISR is schedule for 2007.

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THEMIS - ISR Support

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  1. THEMIS - ISR Support H. Vo, Arecibo Observatory

  2. The geomagnetic context of NSF UAF ISR G M M G Nighttime Daytime

  3. ISR Locations With AMISR, the UAF ISR gives E from pole to equator. Poker Flat ISR will completed by 2006 Resolute ISR is schedule for 2007

  4. ISR Measured ParametersTi, Te, Ne, Viat ALL time when it is operated

  5. UAF ISR Operation • Each ISR radar is contracted by the NSF to run about 1000 hours per year. • Many mode of operations can be run depend on the user request. • For THEMIS coordinated study, the ISR will need to run in a high time resolution mode for electric field measurement. • Data is deposited in www.openmadrigal.org • It is desirable to know in advance the best window of operation. • Contact point: Hien Vo, hvo@naic.edu. • The unique opportunity should be utilized by NASA - NSF

  6. RCM + MHD : Toffoletto ICS 5 Difference in NENL vs CD model

  7. Planning. • It has been difficult in the past to coordinate ISR with satellite. • ISR radars need to be scheduled well in advance esp at Arecibo - radio astronomy. • NASA - NSF collaboration !

  8. Dayside convection change associated with triggered events Coordinated radar run with all radars for the study of penetrating and over-shielding electric field.

  9. Ionospheric control of the magnetosphere, MIT system • Ionosphere is not a passive system • BBF and plasmoid have been observed with no substorm developed. • Thus it is possible that the ionosphere can play a role. • Detailed MIT modelling results have been run for substorm onset. - Coordinated ground data is needed to answer.

  10. Horizontal ion drifts and plasma densities at the poleward auroral boundary 150 km 350 km Note: Blue curve is the boundary extracted from satellite imagery Semeter et al., GRL 2003b

  11. Substorm over Sondrestrom 00:58 UT 01:00 UT 01:02 UT 01:04 UT Semeter and Kamalabadi, Rad. Sci, 2004; Semeter et al., JGR 2005 (in press)

  12. 8e11 1e11 2e10 400 200 Ne (m-3) 2900 1500 1000 400 200 Te (K) 1800 1000 200 Altitude (km) 400 200 Ti (K) 400 0 -400 600 400 200 Vi (ms-1) Semeter and Kamalabadi, Rad. Sci, 2004

  13. Auroral surge over Sondrestrom Narrow-field camera. 25 Frames/sec>640 nm 21 km 150 km Sondrestrom IS radar Electron density1km X 1.2 sec resolution 80 km Semeter and Doe, JGR 2002; Semeter and Kamalabadi 2004

  14. Horizontal ion drifts and plasma densities at the poleward auroral boundary 150 km 350 km Note: Blue curve is the boundary extracted from satellite imagery Semeter et al., GRL 2003b

  15. EISCAT and magnetometer observations of the DP2 electric field (Kikuchi et al., JGR 1996, p.17161)

  16. Arecibo can give 2 components of E with 1 minute time resolution

  17. Latitudinal Profile of the DP2 (Kikuchi et al., JGR 1996, p.17161)

  18. Instantaneous Propagation of DP2 electric field to the Equator The DP2 fluctuations (period of 40 min) at Mokolo and Nurmijarvi are coherent with a correlation coefficient of 0.9. The time shift between the magnetic fluctuations is 25 sec, suggesting instantaneous propagation of the convection electric fields to the equatorial ionosphere. (Kikuchi et al., JGR 1996, p.17161) Mid Latitude R = 0.9 T = 25 sec Equator

  19. Simultaneous onset of the growth phase of a substorm at high latitude and the dayside dip equator Kikuchi et al. (ASR2000) High latitude 15 MLT Equator

  20. Pi2 Substorm DP2 Kikuchi et al. (JGR 2000, p.17161) Equatorial enhancement of the negative bay (DP1) Pi2 DP2 Substorm 17 MLT 15 MLT

  21. Latitudinal Profile of the Negative Bay (DP1) Kikuchi et al. (JGR 2000, p.17161)

  22. Kikuchi et al. (JGR 2000, p.17161) Estimated electric fields associated with the R1 and R2 FACs at auroral and mid latitudes 17 min • E2 develops in response to E1, but is delayed by 17 min. • E2 can be comparable to 0.4E1 at Nurmijärvi around the peak of the negative bay (1430 UT), resulting in the shielding or over-shielding at lower latitudes.

  23. Equatorial counter-electrojet caused by the sudden decrease in the convection electric field Kikuchi et al. (JGR2003) Polar cap Ancon,Peru San Luis, Brazil Jicamarca

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