Dynamic and Buoyancy Pressure

A rising thermal

plus…

Unix basics

Some Unix basics(basis of Linux and Mac OS X)

• The command prompt is $ (do not type it)• Unix commands presented in Courier font$ ls

[lists your “visible” files]$ ls -a

[lists all files, including invisible]$ ls -al

[lists all files, includes size & other info]$ pwd

[print working directory - shows your location]

Some Unix basics(continued)

$ mkdir TEST[makes a directory called “TEST”]

$ cd TEST[changes directory to “TEST”]

$ cd ..[moves UP in directory hierarchy]

$ cd TeST[command should FAIL… Unix is usually CASE SENSITIVE – though it isn’t on Mac]

Some Unix basics(continued)

$ touch crap.txt[makes an empty file]

$ nedit crap.txt OR$ kwrite crap.txt

[invoked Notepad-like text editor on Synoptic Lab machines][add some text, save file and exit]

$ ls -al crap.txt[see it’s there]

$ cp crap.txt crap.txt.backup[make a copy with cp]

$ rm crap.txt[the remove command. Asks for confirmation. Don’t type ‘y’]

$ \rm crap.txt[remove without confirmation. Think before hitting ENTER!]

Some Unix basics(continued)

$ mkdir BACKUP[makes a new directory]

$ cp crap.txt.backup BACKUP/.[type exactly as written - there is NO space before the period][the period means “keep the same name”]

$ ls -al BACKUP/[see a copy is in the new location]

$ mkdir BACKUP/more_backup[a new subdirectory in a directory]

$ cd BACKUP/more_backup[move to new subdirectory]

$ cd$ pwd

[cd by itself always takes you to your home directory]

Some Unix basics(continued)

$ cp /home/fovell/part* .[asterisk is wild card character][copies all files matching text pattern to your directory]

$ ls part*[lists files matching pattern]

$ cat part1 part2 > both_parts[concatenates files][greater-than sign is output redirect]

$ more both_parts[more lists contents, one screen at a time][hit space bar for next screenfull, type “q” to quit]

Your Unix PATH

$ cp /home/fovell/execute_me .

$ execute_me

- if you receive execute_me: command not found your PATH needs changing

- The PATH is an environment variable that tells Unix where to find stuff, and the order in which to look

$ ./execute_me

- this forces Unix to look in the current directory for the program to run

Fortran compiler

• Try this command$ which ifort

• If you get this… we definitely need to alter your Unix environment

$ ifort: Command not found

Preparation for new users[“old” users may have a .cshrc file instead]

$ cd$ mv .tcshrc .tcshrc_old

[mv is move command][.tcshrc or .cshrc is a script file of commands, paths, etc., executed for every new terminal window]

$ cat .tcshrc_old /home/fovell/addon.csh > .tcshrc [type exactly as shown][greater-than sign is output redirect]

$ source .tcshrc[changes to script file in present window do not take effect until “sourced”]

$ which ifort[now you should see: /opt/intel/Compiler/11.1/046/bin/intel64/ifort ]

$ which gradsnc[see /home/fovell/grads-1.9b4/bin/gradsnc ]

DTDM on our Synoptic Lab Linux computers

• Synoptic Lab computers open during business hours ONLY and printing is difficult

$ cp /home/fovell/DTDM_package_linux.tar . [note space and period!]

$ tar –xvf DTM_package_linux.tar

$ cd DTDM

$ make [makes the dtdm executable file]

Using DTDM - 2

$ dtdm < input_thermal.txt [runs model, makes output] [less-than sign provides contents of txt file to the dtdm executable]

$ gradsnc -l [starts up GrADS; ga-> is GrADS prompt]ga-> open thermal.anelasticga-> query file

Using DTDM - 3File 1 : DTDM demo simulation Descriptor: thermal.anelastic.ctl Binary: thermal.anelastic.dat Type = Gridded Xsize = 99 Ysize = 1 Zsize = 82 Tsize = 11 Number of Variables = 17 u 82 0 horizontal velocity up 82 0 pert horizontal velocity w 82 0 vertical velocity th 82 0 potential temperature thp 82 0 pert potential temperature pi 82 0 ndim pressure pip 82 0 pert ndim pressure ppmb 82 0 pert pressure in millibars pbyc 82 0 buoyancy pressure in millibars pdyn 82 0 dynamic pressure in millibars ptot 82 0 total pressure in millibars dudtd 82 0 U acceleration - dynamic dudtb 82 0 U acceleration - buoyancy dudtt 82 0 U acceleration - total dwdtd 82 0 W acceleration - dynamic dwdtb 82 0 W acceleration - buoyancy dwdtt 82 0 W acceleration - total

• running dtdm model created two new GrADS files:thermal.anelastic.ctlthermal.anelastic.dat

• contents of thermal.anelastic.ctlshown at left

ga-> set t 6ga-> start.gsga-> d thp

ga-> d ppmb

ga-> cga-> set ccolor 1ga-> d pbyc

ga-> cga-> set ccolor 1ga-> d pdyn

ga-> cga-> set ccolor 1ga-> d w

ga-> cga-> set gxout shadedga-> d wga-> set gxout contourga-> set ccolor 1ga-> d dwdttga-> scripts/cbarn.gs

dwdtt isLagrangiandw/dt, notEulerian

ga-> cga-> set t 9ga-> set ccolor 1ga-> set cint 2ga-> d w

scripts/thermal.gs

'set mproj off''set display color white''clear''set grads off''scripts/rgbset.gs'* plot w'set x 30 70''set gxout shaded''set clevs -12.5 -10 -7.5 -5 -2.5 0 2.5 5 7.5 10 12.5''set ccols 49 47 45 43 41 0 61 62 63 65 67 69''d w''scripts/cbarn.gs''set gxout contour'

ga-> set t 6ga-> scripts/thermal.gs

Final cautions

• Make backups

• This command runs the model$ dtdm < input_thermal.txt

• This command destroys the input file!$ dtdm > input_thermal.txt

Animations made painless

ga-> step.gs thp 1.0 1 11

Plots field thp…with contour interval 1.0…and steps through times 1 through 11, inclusive…hit return to proceed to the next time

Advice

• Don’t ask what’s the least you can do for me. Instead, ask what’s the most you can do for yourself.