(f) Plot EUVI Subimage Time Sequence + GOES Light Curve

For an overview of the evolution of a selected region on the Sun (i.e., an active region) it is convenient to plot a time sequence of EUVI subimages along with the GOES soft X-ray light curve. We can do this taks with the IDL procedure EUVI_EVOL.PRO.

IDL>
datadir='$secchi/lz/L0/' ;disk or data archive
date ='20080325' ;'YYYYMMDD' date of observation
tstart ='184000' ;'HHMMSS' start time interval for image selection
tend ='192000' ;'HHMMSS' end time interval for image selection
sc ='a' ;spacecraft "a" or 'b'
wave ='171' ;wavelength '171','195','284', or '304' (Angstroem)
color=0 ;0=automated scaling of dynamic range, 1=interactive
movie=0 ;0=automated movie play, 1=interactive stepping of images
fov=[100,500,600,1100] ;[i1,j1,i2,j2] pixels of field-of-view
mismax =0 ;maximum offset (in pixels) for misalignment correction by cross-correlation
iseq=[4,5,6,7] ;indices of images selected for display (iseq=[-1] for equidistant times)
nmin =3 ;3 or 5 min smoothing of GOES light curve
id =-1 ;ID number of event in EUVI event catalog (id=-1 if not used)
nsme =0 ;(currently unused parameter)
area =[0.5,0.4,0.75,0.9] ;fractional field-of-view area of EUV light curve [x1,y1,x2,y2]
filename=date+'_'+tstart+'_'+wave+'_'+sc+'_' ;filename of plot
dir ='~/work/' ;work directory
euvi_files,datadir,date,tstart,tend,sc,wave,datafiles
euvi_display,datafiles,color,movie,images,index
euvi_fov,images,color,fov,images_fov,index,mismax
euvi_evol,date,tstart,tend,index,images_fov,iseq,sc,wave,nmin,id,nsme,area,pos,dir,filename


In this time interval we obtain a sequence 31 images. From these 31 images (with IDL index 0,1,...,30) we choose the subset of ISEQ=[4,5,6,7] for our plot. Let us suppose that you clicked the bottom left corner (BLC) and the top right corner (TRC) of the FOV that encompasses the active region at the south-east limb, say at FOV=[0,500,500,1000]. The resulting plot looks then like this:




The upper panel shows the GOES soft X-ray light curves (thin solid curves), the time derivative, which is a proxy for the hard X-ray light curve according to the Neupert effect (thick solid curve). The times of the 31 images are marked with vertical dotted lines, the displayed 4 images with vertical solid lines, and the EUV light curve (averaged over the fractional image area (0.5-0.75 of the x-range and 0.4-0.9 of the y-range) is shown with a dashed curve and diamond symbols. Note the EUV dimming by 25.3% over the selected area with a size of 146 Mm in x-direction and 291 Mm in y-direction (information is given in title of plot). The second panel shows the 4 images (of the chosen sequence numbers ISEQ), and the third panel shows difference plots, which indicate the dynamic changes in the flaring region (white is flux increase, while black denotes flux decreases). Note that the difference images nicely enhance the expanding CME bubble, which is not visible in the original images. You should also find a postscript file of this plot in your directory with the filename: 20080325_184000_171_a_evol_col.ps