1. Teriaca, et al (2003) ApJ, 588, 596 + SOHO/CDS HIDA/DST 2002 campaign
SOHO/CDS and ground based observations of signatures of chromospheric evaporation in flares
Teriaca, et al (2003) ApJ, 588, 596 +
SOHO/CDS HIDA/DST 2002 campaign

2. Summary of paper Coordinated observations by SOHO/CDS and Sac
　　Peak/NSO/DST
　Comparison of development of chromospheric,
　　transition region and coronal intensities and velocity
　　field during a two-ribbon flare.
　First quasi-simultaneous/spatially resolved　
　　observations of the velocity field in both the
　　chromosphere and upper atmosphere during 　　
　　impulsive phase.
　Oppositely directed flows are detected in the same
　　spatial location at different atmospheric levels for the
　　first time.
　Evidence of chromospheric evaporation.

3. Summary of observations
DST
CDS
Chromospheric lines:
Ca II K, H alpha
He I 5876A, He I　10830A
FOV: 160” x 140”
Spatial resolution:
1” x 1” H alpha
2” x 2” Ca II, He I
Temporal resolution:
A few seconds H alpha.
5 min. for others (2” steps)
Most H alpha unuseable
Lower Transition Region:
He I 584A, He II 304A
Upper Transition Region:
OV 630A
Corona:
Fe XVI 360A, Fe XIX 592A
FOV: 148” by 138”
Spatial resolution:
4” x 3”.4 pixel (6” x-steps)
Temporal resolution:
5 ½ min.

4. GOES-8 0.5-4A flux light curve & derivate
HXR
Peaks
16:01
16:13
SXR
Peak
16:20
Temporal derivative of soft X-ray flux used as a
proxy for hard X-ray emission

5. H alpha flare – GOES C1.1 filament neutral line (MDI) filament
Filament erupted (16:00), two ribbons developed, 2nd energy release (16:13), 40min. decay phase, filament reappeared (16:34).

6. He I (black dots) / H alpha images
White solid FeXVI
Black solid OV Black solid FeXIX

7. Important points of previous figure
　TR flare kernels coincide with chromospheric
footpoints of flaring loops.
He I and OV intensities peak in the earliest phase of
flare (16:02) then decreases with time, but continue to
outline the chromospheric flaring areas.
Maximum coronal emission between the ribbons.
Area and intensity increase with time, peaking at 16:20.
Therefore, He I & OV peak at time of 1st HXR peak. Fe XVI & Fe XIX peak at time of soft X-ray peak.

8. Light curve at position of max. OV brightening
Impulsive peaks H alpha, He I, OV. Second peak H alpha, He I.
Gradual rise to soft X-ray peak in Fe XVI, Fe XIX.

9. Velocity Evolution　
Upflows and downflows have previously been reported in TR lines.
Teriaca et al. found that the flows in H alpha & He I were similar.
O V
He I
Line profiles at the time of max. velocity in OV:
He I – intensity increase and red-shifted absorption
O V – blue-shifted ( km s-1)

10. Velocity Evolution (cont.)
Chromospheric downflows
> 10 mins.
Fe XIX
Enhanced blue wing
(160+/-70 km s-1)
TR upflows only at 1 time

11. He I 10830A (up-black dot, down-black solid) <40 km s-1
White OV 629A (up) <100km s-1
Filament Eruption
Spatial coincidence of chromsopheric
downflow & TR upflow
Strongest velocities in HeI, OV not co-spatial with coronal emission -> adjacent hot/cool loops?

12. Main result He I 10830A chromospheric downflows (40kms-1)
He I 584A lower transition region (log T=4.3) upflows (50kms-1)
OV 629A upper transition region (log T=5.4) upflows (100kms-1)
Fe XIX 592A coronal (log T=6.9) upflows (160kms-1)
All measured quasi-simultaneously at the same spatial location for the first time.

13. Discussion 1 Eruption of filament triggers flare.
Rising filament stretches overlying magnetic field
-> reconnection.
Filament reappears later, suggests only a portion
was affected.
Coronal emission located between chromos./TR
footpoints and had longer evolutionary time -> HXR,
TR emission related to impulsive energy release,
thermal phase is an atmospheric response.

14. Discussion 2 layers originate from same flare kernels ->
Oppositely directed flows in different atmospheric
layers originate from same flare kernels ->
chromospheric evaporation.
Momentum balance: Pdown=1.2-12x1019g cms-1
Pup =2-6.9x1019g cms-1
BUT time-delay between CDS & DST > typical
duration of impulsive bursts (30-90s)
-> not same flaring episode, probably distinct events
within same area.
OV velocity contours suggest TR loops adjacent to
coronal loops -> need multistructure hydro-models
to explain chromospheric evaporation in TR/corona
simultaneously.