1 / 16

Dynamics of reconnection and multiple activation of substorms

Dynamics of reconnection and multiple activation of substorms. Study X-line signatures and examine their relationship to substorm development -Current sheet observations Jan. 09, 2008 ~ 700 UT event Feb.16, 2008 ~ 220 UT event -Remote sensing Feb.10, 2008 425UT, 545 UT event.

damien
Download Presentation

Dynamics of reconnection and multiple activation of substorms

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Dynamics of reconnection and multiple activation of substorms Study X-line signatures and examine their relationship to substorm development -Current sheet observations • Jan. 09, 2008 ~ 700 UT event • Feb.16, 2008 ~ 220 UT event -Remote sensing • Feb.10, 2008 425UT, 545 UT event 2008/02/26 Rumi Nakamura (IWF/OEAW)

  2. Major conjunction ~0700UT AE ~400 nT With multiple activations

  3. Tailward evolution of X-line THB: lobe  PSBLPS I: BY increase II: Bz -  Bz + THC: PSBL lobe  PS I: BY increase, Bx decrease short dBz>0 while Bz decrease II: Bz -  + THD, THE: two dipolarizations I: 654 UT THE  THD II: 722 UT THD, THE Thinning CS Dipolarization I II

  4. For reconnection current sheet, Determine flow reversal is useful DATA QUESTION? How far can we use ESA,SST moments. Looks SST portionimportant. What should we do ?

  5. BBF-like signatures observed at D and E with differences (interesting to compare for these two different activations) DATA QUESTION? SST moment is important!? THD THE

  6. 20080109 07UT event summary • Modest substorm with multiple activations (AE 400 nT) • Bz reversal (flow reversal?) observed by B and C with time difference  motion/evolution of Xline. • Two dipolarizations observed by D-E I. during current sheet thinning at C and B II. associated with X-line at C (and B) Plan: Confirm X-line signatures with particle/field data, compare flow evolution for I. II.

  7. centered high-lat. (Rank) or Greenland(?, tbd) Minor conjunction 0220 UT - AE ~250 nT

  8. Bz reversal around II Two X-line activations rather than in-site Xline observation? THC: PSBLPS I: negative Bz tailward of Xline II: postive Bz earthward of X line THD, THE : dipolarization I: ~220 UT II:~0244 UT Dipolarization I II

  9. For studying reconnection current sheet, determine flow reversal timing is very important DATA QUESTION? Similar to 20080109 event, SST seems to show reversal... How far can we use ESA,SST Moments?Recommendation ? Like 20080109 event THEMIS D and E have also similar issue

  10. Similar to 20080109 eventBBF-like signatures observed at D and E with differences (interesting to compare for these two different activations) DATA QUESTION? SST moment is important!?

  11. 20080216 0220UT event summary • Small activation (high-lat.) (AE ~250 nT) • +Bz and –Bz enhancement (or Bz reversal) observed by C associated with two dipolarization event (D, E) and ground-based activation. Different activation of X-line(s?) at different location (first Earthward then tailward side of C) • Plan: Confirm X-line signatures with particle/field data (Timing of flow reversal essential) Compare flow evolution for I. II.

  12. Two small activationscentered high-lat. (Rank) or Greenland(?, tbd) Major conjunction 0430UT AE ~200 nT 0540UT AE ~350 nT

  13. Remote X-line sensing between C and B THB: Tail lobe Bz +  - THC: lobe/PSBL Bz -  + 1 flux rope, 2 TCR D, E: expansion of plasma sheet

  14. Relationship between earthward motion of flux ropeand innermagnetospheric signatures could be studied THB THD DATA QUESTION? Is this taiward flow OK ? THE The spectra around 0552-55 UT may look dark region at two place? (multi composition ?)

  15. Tailward motion or two of very weak TCR ? THB: lobe Bx - , Bz - THC: lobe Bx + , Bz -

  16. 20080210 0430-0550 UT event summary • Two modest activations (200, 350 nT) • Lobe/PSBL signatures may allow to remote-sensing the X-line • Plan: Using transient reconnection model (Semenov et al., 2007) to model location/motion of X line, temporal change of reconnection rate (by Stefan Kiehas) • .. We are still on search of this kind of event...

More Related