1. TRACE Downflows and Energy Release
Ayumi ASAI
Kwasan Observatory, Kyoto University
SOHO de Mallorca
30 September, 2003

2. Downflow Motion
Yohkoh (SXT) has found downflows above post-flare loops
McKenzie and Hudson 1999
McKenzie 2000
velocity: 45–500 km/s
dark feature
often seen in the decay phase of LDEs
Yohkoh/SXT : McKenzie 2000

3. TRACE Downflow
Recently TRACE also has found the downflows above post-flare loops
Innes et al. (2003)
spectroscopic analyses with SOHO/SUMER
flow of rarefied plasma?
we examine such TRACE downflow motions with higher spatial resolution
we examine evolution of the region where the downflows are seen
ex) : 21 April, 2002 flare

4. 2002 July 23 Flare Flare 2002-July-23 00:15UT GOES X4.8
NOAA 0039
Flare
2002-July-23 00:15UT
GOES X4.8
NOAA 0039 (SE limb)
Data
EUV…TRACE (195Å)
HXR...RHESSI
microwave…NoRH
GOES flux
NoRH 17GHz
NoRH 34GHz
00:00
02:00
01:00

5. TRACE (195Å) Movie EUV (195Å) images obtained with TRACE
This filter is sensitive to
106 K plasma
and
107 K plasma
East
West

6. Time Slice Image Time slice image downflow super hot plasma (10MK)
TRACE 195Å
post-flare loop (1MK)
time

7. Velocity of Downflows downflow velocity: 100 – 250 km/s
Time slice image
TRACE 195A
slit A
slit A
slit B
downflow velocity:
100 – 250 km/s
~previous results
slit B

8. Time of Downflows
Time slice image
These TRACE downflows are seen not only in the decay phase but also in the impulsive phase and main phase
GOES
NoRH 17GHz
NoRH 34GHz
00:00
01:00
02:00

9. Timing of Downflows
Time slice image
TRACE 195A
slit A
slit A
slit B
The timings of the down flows correspond to microwave/HXR bursts.
slit B
RHESSI keV

10. Timing of Downflows
Time slice image
TRACE 195A
slit A
slit A
slit B
The timings of the down flows correspond to microwave/HXR bursts.
slit B
NoRH 17GHz

11. Ascending Loop Top Time slice image ascending velocity ~ 40 km/s
super hot plasma (10MK)
TRACE 195Å
post-flare loop (1MK)
~ 20 km/s
time

12. Ascending Motion superhot region moving upward as the flare progresses
height
velocity
microwave
HXR
superhot region moving upward as the flare progresses
ascending velocity is enhanced when nonthermal bursts occur

13. Summary Features of the TRACE Downflow Motion
speed : km/s
seen in the impulsive-main-decay phase
Downflows show good correlations with HXR/microwave bursts
downflows are closely related to reconnection outflow!?
Superhot region ascends when the nonthermal bursts occur (Neupert effect)

14. Multiple Plasmoid Ejection
Multiple plasmoid-ejections
2000 November 24 flare shows many plasmoid ejections, and each of them is ejected at the time corresponding to the HXR burst.
Takasaki (2003)
Time slice image
Yohkoh/SXT

15. Reconnection Outflow?
plasmoid ejection
Many plasmoids (magnetic islands) are formed in a current sheet.
They consist the reconnection outflows.
upward ejection :
plasmoid ejections
downward ejection :
downflows
downflows

16. Comparison plasmoid ejection downflow velocity [km/s] 30-500 45– 500
size [km]
1-10･104
2-10･103
density [cm-3]
1-10･109
~109
impulsive ph.
Yes
decay ph. No
HXR/m-wave

17. What are Downflows…? propagation of reconnection outflows
Tandokoro (2003)

18. What are Downflows…?
simulation
observation

19. Ascending Motion (RHESSI)
height
velocity
microwave
HXR
HXR coronal source is also pushed upward when nonthermal bursts occur
Krucker 2003

20. corrected separation velocity ~ 25 km/s
Evolution of Ha Ribbon
slit
projected
separation velocity
~ 7 km/s ↓
corrected separation velocity ~ 25 km/s