Mapping Exercise Answer

To plot the map on the 310 K theta surface, just ask for it. GEMPAK will do the vertical interpolation of the sounding data for you!

 GEMPAK-SNMAP>vcoord=thta
 GEMPAK-SNMAP>levels=310
 GEMPAK-SNMAP>dis
 AREA      Data area                         us
 GAREA     Graphics area                     usnps
 SNPARM    Sounding parameter list           brbk;tmpc;;hgtd;;dwpc
 DATTIM    Date/time                         18/12
 LEVELS    Vertical levels                   310
 VCOORD    Vertical coordinate type          thta
 SNFILE    Sounding data file                $GEMPAKHOME/data/hrcbob.snd
 COLORS    Color list                        1;2;3;25;5;6;7;9
 MAP       Map color/dash/width              3/1/1
 LATLON    Line color/dash/width/label/inc   0
 MARKER    Marker color/type/size/width/hw   0 
 TITLE     Title color/line/title            1/-2
 CLEAR     Clear screen flag                 YES
 PANEL     Panel location/color/dash/width   0
 DEVICE    Graphics device                   xw
 PROJ      Map projection/angles/margins     nps
 FILTER    Filter data factor                0.7
 TEXT      Text size/font/width/hw flag      1.3/23//HW
 GEMPAK-SNMAP>r
  vparm is THTA
 SNMAP PARAMETERS:
 
 Data area:          us                                              
 Graphics area name: usnps                                           
 Valid parameters:    BRBK TMPC BLNK HGTD BLNK DWPC
 Parameter colors:     1    2    0    3    0   25 
 Time:              910818/1200         
 Level:                310
 Vert coord:          THTA
 File:              $GEMPAKHOME/data/hrcbob.snd                                 
 Map:               3/1/1                   
 Marker:            0                       
 Title:             1/-2                                            
 Device:            xw                      
 Projection:        nps                             
 Clear screen:      YES
 Filter:            YES
 Filter factor: 0.70
 Panel:             0                                               
Enter <cr> to accept parameters or type EXIT:

Okay, now do the same thing for 6000m heights, this time set the filter to 0.7 so that you get more data.

 GEMPAK-SNMAP>vcoord=hght
 GEMPAK-SNMAP>levels=6000
 GEMPAK-SNMAP>filter=0.7
 GEMPAK-SNMAP>d
 AREA      Data area                         us
 GAREA     Graphics area                     usnps
 SNPARM    Sounding parameter list           brbk;tmpc;;hgtd;;dwpc
 DATTIM    Date/time                         18/12
 LEVELS    Vertical levels                   6000
 VCOORD    Vertical coordinate type          hght
 SNFILE    Sounding data file                $GEMPAKHOME/data/hrcbob.snd
 COLORS    Color list                        1;2;3;25;5;6;7;9
 MAP       Map color/dash/width              3/1/1
 LATLON    Line color/dash/width/label/inc   0
 MARKER    Marker color/type/size/width/hw   0
 TITLE     Title color/line/title            1/-2
 CLEAR     Clear screen flag                 YES
 PANEL     Panel location/color/dash/width   0
 DEVICE    Graphics device                   xw
 PROJ      Map projection/angles/margins     nps
 FILTER    Filter data factor                0.7
 TEXT      Text size/font/width/hw flag      1.3/23//HW
 GEMPAK-SNMAP>r

Vparm is HGHT
 SNMAP PARAMETERS:

 Data area:          us                                              
 Graphics area name: usnps                                           
 Valid parameters:    BRBK TMPC BLNK HGTD BLNK DWPC
 Parameter colors:     1    2    0    3    0   25 
 Time:              910818/1200         
 Level:               6000
 Vert coord:          HGHT
 File:              $GEMPAKHOME/data/hrcbob.snd                                 
 Map:               3/1/1                   
 Marker:            0                       
 Title:             1/-2                                            
 Device:            xw                      
 Projection:        nps                             
 Clear screen:      YES
 Filter:            YES
 Filter factor: 0.70
 Panel:             0                                               
Enter <cr> to accept parameters or type EXIT: