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

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.

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.

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

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).

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

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.

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.

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 (100-125 km s-1)

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

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?

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.

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.

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.