Tutorial on Bifrost simulations: hands on lab and quicklook tools

Transcription

1 Tutorial on Bifrost simulations: hands on lab and quicklook tools Juan Martínez-Sykora Boris Gudiksen Bifrost team See ITN 33 and 34

2 Documentation Bifrost code paper: Gudiksen et al includes some of the information shown in this keynote

3 Bifrost files Select the desire variables Select the desire snapshots

4 Latest SSW routines and setup: Copy only the tar files we provided on your machines (/Volumes/IRIS-4/bifrost\ simulations/*tar.j) and uncompress them: find. -maxdepth 1 -name '*.tar.j' -exec tar xfvj '{}' \; Unless you did SSW upgrade today, then, - Download the zip file form - Uncompress and copy idlbifrost/* into your ssw/iris/idl/uio/bifrost/ - (cp -r idlbifrost/* ssw/iris/idl/uio/bifrost/) Create BIFROST environment, e.g., in c-shell: setenv BIFROST ~/bifrostcode/ And create the path mkdir -p ~/bifrostcode/idl/data/lines Make sure that SSW_INSTR includes iris and, if possible chianti too. setenv SSW_INSTR chianti iris Check that in sswidl print,xuvtop and print,abund_file shows proper paths use_chian*,xuvtop,abund='$ssw/packages/chian*/dbase/abundance/sun_photospheric_2011_caffau.abund'

5 getting started br_select_fits,fitn ; search for root name of the files 1) dd=obj_new('br_data',fitn) ; creates the object 2) var='tg' ; name of the variable of interest 3) it = 385 ; snapshot number 4) dd->load,var,it ; load into the object the desired variable ; (var) 5) tg=dd->getvar() ; always after line 5 and save the data in tg 6) tg=dd->getvar(var,it) ; this is the same as lines 5+6 at once. 7) z=dd->getz() ; loads in z the z axis. getx() and gety() is for ; x and y axis. It should be done after ; dd->load or dd->getvar 8) time=dd->gett() ; loads time of the selected snapshots. ; It should be done after dd->load or ; dd->getvar 9) br_xmhd,dd ; launches the quick look tool 10) br_xmhd demo

6 Other ways to fill the object it=385+indgen(8)*2 dd->load,var,it dd->load,var,it,iz=100 dd->load,var,it,ix=100 dd->load,' ',0 ; Loading slides cuts as a function of time ; time range ; It will load always a 3D or lower dimension ; cube. If it is a vector, the default is iy=0 ; One could choose xy cuts: ; where 100 is the position along the z axis, ; or yz: ; one can do the same for iy too. ; will provide a list of variables ; all of this options can be used also with dd->getvar ; try this options using the quick-look tool br_xmhd. Note that field lines will not make sense with when one axis is time. br_make_fits_level3 allows to create level 3 fits files from the simulation in order to use crispex. The spectral axis will become the third spatial axis.

7 Other variables (this is not the full list) ux, uy, uz :: Velocity bx, by, bz :: Magnetic field px, py, pz :: momentum e :: internal energy per volume ee :: internal energy per particle r :: density p :: gas pressure pb :: magnetic pressure pt :: total pressure beta :: plasma beta cs :: sound speed va :: Alfven speed ne :: electron density lgr :: log(r) lgtg :: log(tg) mod? :: module of any vector, where? is the first letter, magnetic field=b A2 :: square of a vector where A is the first letter of the vector. AperpB :: calculates the component perpendicular of the vector A with respect to B, where A and B are the first letter of the vector s name. AparB :: calculates the component parallel of the vector A with respect to B, where A and B are the first letter of the vector s name. si4_1402_p :: EUV emission of using CHIANTI data base and optically thin radiation. The first (one or two) letter are the element, the first number is the ionization level and the next number is the wavelength in Å. (try other lines)

8 Exercise (needs CHIANTI) 1) Can we see UFS in the simulation? - Choose a TR spectral line (e.g., si4_1402_p) and synthesize the image integrating along z axis - Find an UFS and see time evolution in intensity 2) Does the UFS observed in the TR emission follow field lines? - Synthesize the emission in one snapshot and identify the UFS. - Trace field lines - Check if the field lines follow the chosen UFS 3) Thermo-dynamic properties along the field line. - Read the desired variables and interpolate the variables along the field line. 4) Time evolution. - Identify the location of the UFS in each snapshot. - Trace field lines for each snapshot following the UFS. - Read the desired variables and interpolate along the field lines for each snapshot. - Plot time evolution along the field lines of the UFS. 5) Feel free to do whatever you desire. We will try to help on this too.

9 Exercise without CHIANTI 1) Do TR loop structures in temperature follow field lines? - Plot temperature in xz or yz plot and search for a loop structure. - Trace field lines - Check if the field lines follow the chosen TR loop 2) Thermo-dynamic properties along the field line? - Read the desired variables and interpolate the variables along the field line. 3) Time evolution. - Identify the location of the loop in each snapshot. - Trace field lines for each snapshot following the loop. - Read the desired variables and interpolate along the field lines for each snapshot. - Plot time evolution along the field lines of the loop. 4) Feel free to do whatever you desire. We will try to help on this too.

10 Help for tracing field lines it=385 ; Snapshot number dd->load,var,it ; load var nx=800 ; limits on number of step along r1 ny=800 ; limits on number of step along r2 zo=min(z) ; bottom of the convection zone ro=[[10,6,6-zo],[11,4,5-zo],[5,7,10-zo]] ; seed points locations ; where z has the be added the length of the convection zone, i.e., zo br_bfieldline,fitn,it,r1,r2,nx,ny,r0=ro ; tracing field lines, ; r1, r2 position of the field lines in each direction br_xmhd,dd,inputfield=[[[r1]],[[r2]]] ; visualize this in the br_xmhd tool