First create a new grid file:
% oagridGEMPAK-OAGRID>GDFILE = barnes1.grd GEMPAK-OAGRID>GRDAREA = us GEMPAK-OAGRID>SOURCE = SF GEMPAK-OAGRID>SFFILE = metar GEMPAK-OAGRID>SFPARM = tmpf;dwpf;pmsl;sped;drct GEMPAK-OAGRID>DATTIM = 1200 GEMPAK-OAGRID>DELTAN = 0
GEMPAK-OAGRID>DELTAX = 0 GEMPAK-OAGRID>DELTAY = 0 GEMPAK-OAGRID>l
GDFILE = barnes1.grd DELTAN = 0 DELTAX = 0 DELTAY = 0 GRDAREA = us EXTEND = 2;2;2;2 DTAAREA = SOURCE = SF SNFILE = $GEMPAK/DATA/HRCBOB.SND SFFILE = metar SNPARM = ;TMPC;;HGHT;DWPC;BRBM SFPARM = tmpf;dwpf;pmsl;sped;drct DATTIM = 27/1200 LEVELS = 500 MAXGRD = 200 GEMPAK-OAGRID>r
OBJECTIVE ANALYSIS PARAMETERS GRIDAREA 19.00 -119.00 46.88 -56.10 (us 47.00 -56.00) DELTAN 0.680 DELTAX 0.340 DELTAY 0.340 GRID POINTS X : 186 ( 2, 2 ) Y : 83 ( 2, 2 ) EXTENDAREA 18.32 -119.68 47.56 -55.42 DATAAREA 18.32 -119.68 47.56 -55.42 CALCULATIONS: FILE /data/ldm/gempak/surface/20101025_sao.gem SOURCE SF 19.00 -119.00 47.00 -56.00 NSTN 1563 PARM TMPF LEVEL 0.0 DATTIM 101025/1200 COMPUTED DATA SPACING 0.369 UNIFORM DATA SPACING 0.999 RECOMMENDED DELTAN = 0.684 DELTAX = 0.408 DELTAY = 0.342 Enter to accept parameters or type EXIT: GEMPAK-OAGRID>e
Now make 3 more copies of the file:
cp barnes1.grd barnes2.grd cp barnes1.grd barnes3.grd cp barnes1.grd barnes4.grd
Next, perform the Barnes Analyses
%oabsfcSFFILE Surface data file metar GDFILE Grid file barnes1.grd SFPARM Surface parameter list tmpf;dwpf;pmsl;sped;drct DATTIM Date/time 27/1200 DTAAREA Data area for OA GUESS Guess file^time GAMMA Convergence parameter 0.3 SEARCH Search radius/Extrapolation 20 NPASS Number of passes 2 QCNTL Quality control threshold OABND Bounds file(s) to use for 'block GDATTIM Grid date/time GFUNC Scalar grid GLEVEL Grid level 0 GVCORD Grid vertical coordinate none Parameters requested: SFFILE,GDFILE,SFPARM,DATTIM,DTAAREA,GUESS,GAMMA, SEARCH,NPASS. GEMPAK-OABSFC>gamma = 1.0 GEMPAK-OABSFC>r
Creating process: gplt for queue 5850 OABSFC PARAMETERS: Output grid file: barnes1.grd Number of x, y points: 143 60 Grid bnds: 25.00 -125.00 49.78 -65.36 Grid xtnd: 2 2 2 2 Station spacing: 0.84 No first guess file is requested. Surface file: $GEMDATA/surface/sao/960227.gem Data area: 24.16;-125.84;50.62;-64.52 Parameters: TMPF DWPF PMSL SPED DRCT Time: 960227/1200 GAMMA: 1.00 SEARCH: 20.00 NPASS: 2 No data extrapolation will occur. Enter to accept parameters or type EXIT: RMS values for pass 1 TMPF DWPF PMSL SPED DRCT RMS 3.31 3.60 0.78 1.70 84.90 #STN 908 876 558 943 943 RMS values for pass 2 TMPF DWPF PMSL SPED DRCT RMS 2.82 3.07 0.63 1.60 79.60 #STN 881 849 539 913 913 Parameters requested: SFFILE,GDFILE,SFPARM,DATTIM,DTAAREA,GUESS,GAMMA, SEARCH,NPASS. GEMPAK-OABSFC> gamma = .5 GEMPAK-OABSFC>gdfile = barnes2.grd GEMPAK-OABSFC>r OABSFC PARAMETERS: Output grid file: barnes2.grd Number of x, y points: 143 60 Grid bnds: 25.00 -125.00 49.78 -65.36 Grid xtnd: 2 2 2 2 Station spacing: 0.84 No first guess file is requested. Surface file: $GEMDATA/surface/sao/960227.gem Data area: 24.16;-125.84;50.62;-64.52 Parameters: TMPF DWPF PMSL SPED DRCT Time: 960227/1200 GAMMA: 0.50 SEARCH: 20.00 NPASS: 2 No data extrapolation will occur. Enter to accept parameters or type EXIT: RMS values for pass 1 TMPF DWPF PMSL SPED DRCT RMS 3.31 3.60 0.78 1.70 84.90 #STN 908 876 558 943 943 RMS values for pass 2 TMPF DWPF PMSL SPED DRCT RMS 2.45 2.67 0.52 1.48 72.96 #STN 874 842 532 905 905 Parameters requested: SFFILE,GDFILE,SFPARM,DATTIM,DTAAREA,GUESS,GAMMA, SEARCH,NPASS. GEMPAK-OABSFC>gamma = .3 GEMPAK-OABSFC>gdfile = barnes3.grd GEMPAK-OABSFC>r OABSFC PARAMETERS: Output grid file: barnes3.grd Number of x, y points: 143 60 Grid bnds: 25.00 -125.00 49.78 -65.36 Grid xtnd: 2 2 2 2 Station spacing: 0.84 No first guess file is requested. Surface file: $GEMDATA/surface/sao/960227.gem Data area: 24.16;-125.84;50.62;-64.52 Parameters: TMPF DWPF PMSL SPED DRCT Time: 960227/1200 GAMMA: 0.30 SEARCH: 20.00 NPASS: 2 No data extrapolation will occur. Enter to accept parameters or type EXIT: RMS values for pass 1 TMPF DWPF PMSL SPED DRCT RMS 3.31 3.60 0.78 1.70 84.90 #STN 908 876 558 943 943 RMS values for pass 2 TMPF DWPF PMSL SPED DRCT RMS 2.13 2.32 0.46 1.35 66.27 #STN 870 838 521 901 901 Parameters requested: SFFILE,GDFILE,SFPARM,DATTIM,DTAAREA,GUESS,GAMMA, SEARCH,NPASS. GEMPAK-OABSFC>gamma = .1 GEMPAK-OABSFC>gdfile = barnes4.grd GEMPAK-OABSFC>r OABSFC PARAMETERS: Output grid file: barnes4.grd Number of x, y points: 143 60 Grid bnds: 25.00 -125.00 49.78 -65.36 Grid xtnd: 2 2 2 2 Station spacing: 0.84 No first guess file is requested. Surface file: $GEMDATA/surface/sao/960227.gem Data area: 24.16;-125.84;50.62;-64.52 Parameters: TMPF DWPF PMSL SPED DRCT Time: 960227/1200 GAMMA: 0.10 SEARCH: 20.00 NPASS: 2 No data extrapolation will occur. Enter to accept parameters or type EXIT: RMS values for pass 1 TMPF DWPF PMSL SPED DRCT RMS 3.31 3.60 0.78 1.70 84.90 #STN 908 876 558 943 943 RMS values for pass 2 TMPF DWPF PMSL SPED DRCT RMS 1.51 1.63 0.38 1.09 51.50 #STN 785 750 381 815 815 Parameters requested: SFFILE,GDFILE,SFPARM,DATTIM,DTAAREA,GUESS,GAMMA, SEARCH,NPASS. GEMPAK-OABSFC>e
Finally, lets plot it up:
> gdcntrrestore defaults/gdcntr.nts gdattim = last glevel = 0 gvcord = none gfunc = tmpf gdfile = barnes1.grd panel = ul clear = y garea = #35;-93;12;27 proj = lea/35;-100;0 fline = 30-7 ctype = f fint = 5 title = 1/-1/GAMMA = 1.0 r clear = n panel = ur gdfile = barnes2.grd title = 1/-1/GAMMA = .5 r
