Track of the tropical cyclone
Charles Seman
Charles.Seman at NOAA.GOV
Fri Apr 7 12:24:19 EDT 2006
Dear Sajjad Saeed,
It may be that the script cannot read your "grb" file (is this a "grib"
file?)... I haven't used the script, but from the documentation, we see
this:
---
*
* Script to draw an hurricane-track plot.
* Does little error checking on the input file.
* Assumes the input file is set up as follows:
*
* Line 1: Title
* Line 2: Drawing primitives for marks: marktype size
* Line 3: Drawing primitives for lines: color style thickness
* Line 4: Starting hour and the interval of plotting points
* e.g., 0 6 means that track starts at 0 hour and mark
* will be plotted every 6 hours.
* Rest of lines: hour long. lat.
* e.g., 0 -70.5 25.0
* 6 -71.8 25.2
* :
* :
*
* Also assumes that a file has been opened (any file, doesn't
* matter -- the set command doesn't work until a file has been
* opened).
*
---
approach 1:
Based on the above documentation, I would say to open your "ctl" file in
GrADS, and then run your "trackcyclone.gs" script, and specify an ASCII
text file containing the locations of the hurricane... if you do not
have these in a text file, perhaps you could adapt the code in file
"hurricane_tracking.txt" (attached, which contains an email exchange
between Arturo Caracas Uribe and Kun-Hsuan Chou to the GrADS Listserv
with code to track the maximum wind speed... ) to generate a script
which you would run before you run "trackcyclone.gs" to generate the
ASCII text file containing the locations of the hurricane...
---
approach 2:
Another idea would be to adapt the code from "hurricane_tracking.txt"...
for example, by putting a time loop around the code, then plotting the
location for each time... I'm not sure what parameter you might be
using? minimum surface pressure, maximum surface vorticity, etc? if
the points are too dense, the time loop increment could be increased
from "1" to "2" or "3" etc (perhaps make this a parameter to be set
before entering the time loop)...
---
I'm not sure if either of the above approaches would help you...
I hope this helps,
Chuck
sajjad saeed wrote:
> Dear Charles
>
> Thankyou for sending the script. I used the script and followin error
> occured.
>
> ga-> trackcyclone.gs
> Enter File Name: (type q to stop)
> pmdada.paj9oct.16222.regrid.ctl
> dset pmdada.paj9oct.16222.regrid.grb
> marktype, marksize, lcolor, lstyle and lthick:
> index pmdada.paj9oct.16222.regrid.grb.idx undef 9.999E+20
> starting hour and the interval hours of plotting points:
> title pmdada.paj9oct.16222.regrid.grb
> endhour=ENDVARS
> SET error: Missing or invalid arguments for LINE option
> DRAW error: Syntax is DRAW MARK marktype x y size
> Non-numeric args to numeric operation
> Error occurred on line 118
> In file trackcyclone.gs
>
> Would you please tell me how can i overcome this problem.
>
> Sajjad Saeed
>
>
>
>> From: Charles Seman <Charles.Seman at NOAA.GOV>
>> Reply-To: GRADSUSR at LIST.CINECA.IT
>> To: GRADSUSR at LIST.CINECA.IT
>> Subject: Re: Track of the tropical cyclone
>> Date: Thu, 6 Apr 2006 16:45:44 -0400
>>
>> Dear Sajjad Saeed,
>>
>> Please find attached a script "plot_hurricane_center.gs" containing
>> GrADS script function code from Joe Covert posted to the GrADS Listserv
>> (his script was named plot_tc_shi.gs), and some documentation from
>> emails about it to the GrADS Listserv, and a file
>> "hurricane_tracking.txt" containing an email exchange between Arturo
>> Caracas Uribe and Kun-Hsuan Chou to the GrADS Listserv with code to
>> track the maximum wind speed...
>>
>> I hope these examples help,
>> Chuck
>>
>> sajjad saeed wrote:
>>
>>> Dear all,
>>> How can we calculate and plot the track of a tropical cyclone in the
>>> grads.
>>> Any help will be appreciated.
>>>
>>> Sajjad Saeed
>>> Meteorologist
>>> Pakistan Meteorological Department /Global Change Impact Studies Centre
>>> Islamabad- Pakistan.
>>>
>>> _________________________________________________________________
>>> Don't just search. Find. Check out the new MSN Search!
>>> http://search.msn.com/
>>
>>
>>
>> --
>>
>> ********************************************************************
>> Charles Seman charles.seman at noaa.gov
>> U.S. Department of Commerce / NOAA / OAR
>> Geophysical Fluid Dynamics Laboratory voice: (609) 452-6547
>> 201 Forrestal Road fax: (609) 987-5063
>> Princeton, NJ 08540-6649 http://www.gfdl.noaa.gov/~cjs/
>> ********************************************************************
>>
>> "The contents of this message are mine personally and do not reflect
>> any position of the Government or NOAA."
>>
>
>
>> *----------------------------------------------------------------------
>> * From Joe.Covert at noaa.gov (via GrADS Listserv on 9/13/2004; his script
>> * was named plot_tc_shi.gs):
>> *----------------------------------------------------------------------
>> **
>> **There appears to be a problem with version 1.9 of GrADS "read"
>> function.
>> **
>> **The plot_tc_shi.gs script (see below) uses the read function to
>> open the
>> **track data file and the program gives the subject error message "File
>> **Error 1".
>> **
>> **jc
>> *----------------------------------------------------------------------
>> * From Diane.Stokes @noaa.gov (via GrADS Listserv on 9/13/2004):
>> *----------------------------------------------------------------------
>> ** Joe,
>> **
>> **Read works fine for me in 1.9.
>> **
>> **I think this is the issue where 'pull' in 1.9 throws in a carriage
>> **return. The read statement is not getting the exact filename.
>> **
>> **Try adding:
>> ** file=sublin(file,1)
>> **after each:
>> ** pull file
>> **
>> **Diane
>> *----------------------------------------------------------------------
>> * From Joe.Covert at noaa.gov (via GrADS Listserv on 9/13/2004):
>> *----------------------------------------------------------------------
>> **worked great ... thanks. joe
>> *----------------------------------------------------------------------
>> *
>> * Script to draw an hurricane-track plot.
>> * Does little error checking on the input file.
>> * Assumes the input file is set up as follows:
>> *
>> * Line 1: Title
>> * Line 2: Drawing primitives for marks: marktype size
>> * Line 3: Drawing primitives for lines: color style thickness
>> * Line 4: Starting hour and the interval of plotting points
>> * e.g., 0 6 means that track starts at 0 hour and mark
>> * will be plotted every 6 hours.
>> * Rest of lines: hour long. lat.
>> * e.g., 0 -70.5 25.0
>> * 6 -71.8 25.2
>> * :
>> * :
>> *
>> * Also assumes that a file has been opened (any file, doesn't
>> * matter -- the set command doesn't work until a file has been
>> * opened).
>> *
>>
>> function main()
>>
>> * 'clear'
>>
>> 'open dummy.ctl'
>> 'set lat 20 50'
>> 'set lon -90 -30'
>> 'set mpdset hires'
>> 'set poli on'
>> 'draw map'
>>
>>
>> say 'Enter File Name: (type q to stop)'
>> pull fname
>>
>> while (fname != 'q')
>>
>> * Read the 1st record: Title
>>
>> ret = read(fname)
>> rc = sublin(ret,1)
>> if (rc>0)
>> say 'File Error 1'
>> return
>> endif
>> title = sublin(ret,2)
>> say title
>>
>> * Read the drawing primitives
>>
>> ret = read(fname)
>> rc = sublin(ret,1)
>> if (rc>0)
>> say 'File Error 2'
>> return
>> endif
>> dpline = sublin(ret,2)
>> marktype = subwrd(dpline,1)
>> marksize = subwrd(dpline,2)
>> ret = read(fname)
>> rc = sublin(ret,1)
>> if (rc>0)
>> say 'File Error 3'
>> return
>> endif
>> dpline = sublin(ret,2)
>> lcolor = subwrd(dpline,1)
>> lstyle = subwrd(dpline,2)
>> lthick = subwrd(dpline,3)
>> say ' marktype, marksize, lcolor, lstyle and lthick:'
>> say ' 'marktype ' ' marksize ' ' lcolor ' ' lstyle ' ' lthick
>>
>> * Read starting hour and the interval hours of plotting points
>>
>> ret = read(fname)
>> rc = sublin(ret,1)
>> if (rc>0)
>> say 'File Error 4'
>> return
>> endif
>> dhour = sublin(ret,2)
>> start = subwrd(dhour,1)
>> jump = subwrd(dhour,2)
>> say ' starting hour and the interval hours of plotting points:'
>> say ' 'start' 'jump
>>
>> * Read all data points
>>
>> ret = read(fname)
>> rc = sublin(ret,1)
>> while (rc = 0)
>> loc = sublin(ret,2)
>> hour = subwrd(loc,1)
>> dlong.hour = subwrd(loc,2)
>> dlat.hour = subwrd(loc,3)
>> * prompt ' hour ' hour ' are read,'
>> * say ' long=' dlong.hour ' lat=' dlat.hour
>> ret = read(fname)
>> rc = sublin(ret,1)
>> endwhile
>>
>> if (rc!=2 & rc!=0)
>> say 'File Error 5, rc=' rc
>> return
>> endif
>>
>> endhour = hour
>> say ' endhour=' endhour
>>
>> * Plotting
>>
>> 'set line 'lcolor' 'lstyle' 'lthick
>> 'query w2xy 'dlong.start' 'dlat.start
>> xprev = subwrd(result,3)
>> yprev = subwrd(result,6)
>> 'draw mark 'marktype' 'xprev' 'yprev' 'marksize
>> next = start+jump
>> while (next <= endhour)
>> * say ' 'dlong.start' 'dlat.start
>> 'query w2xy 'dlong.next' 'dlat.next
>> xnext = subwrd(result,3)
>> ynext = subwrd(result,6)
>> 'draw line 'xprev' 'yprev' 'xnext' 'ynext
>> * say ' 'xprev' 'yprev' 'xnext' 'ynext
>> 'draw mark 'marktype' 'xnext' 'ynext' 'marksize
>> next = next+jump
>> xprev = xnext
>> yprev = ynext
>> endwhile
>>
>> say fname ' is working fine.'
>>
>> * read in the filename to be plotted next
>>
>> say 'Enter File Name: (type q to stop)'
>> pull fname
>>
>> endwhile
>
>
>
>> *
>> *
>> * Subject: Re: Tracking Hurricanes
>> * From: Kun-Hsuan Chou <cwujou at TYPHOON.AS.NTU.EDU.TW>
>> * Date: Fri, 8 Oct 2004 08:03:20 +0800
>> * To: GRADSUSR at LIST.CINECA.IT
>> *
>> * Hi,
>> *
>> * I write a sample to track the maxminum wind speed, it should be the
>> script that you want.
>> *
>> 'd maxloc(max(mag(u,v),lon=120,lon=130),lat=15,lat=25)'
>> line=sublin(result,2)
>> ygrd=subwrd(line,4)
>> 'd maxloc(max(mag(u,v),lat=15,lat=25),lon=120,lon=130)'
>> line=sublin(result,2)
>> xgrd=subwrd(line,4)
>> 'set x 'xgrd
>> lonval = subwrd(result,4)
>> 'set y 'ygrd
>> latval = subwrd(result,4)
>> 'q w2xy 'lonval' 'latval
>> xpos = subwrd(result,3)
>> ypos = subwrd(result,6)
>> 'draw mark 1 'xpos' 'ypos' .2'
>>
>> *============================================================================
>>
>> *Kun-Hsuan Chou
>> *Postdoctoral Researcher
>> *Department of Atmospheric Sciences
>> *National Taiwan University
>> *No. 1, Sec. 4, Roosevelt Rd., Taipei 106, Taiwan.
>> *Phone: 886-2-23625896 ext. 243
>> *Mobile: 0920079247
>> *E-mail: cwujou at typhoon.as.ntu.edu.tw
>> *----- Original Message -----
>> *From: Arturo Caracas Uribe
>> *To: GRADSUSR at LIST.CINECA.IT
>> *Sent: Thursday, October 07, 2004 11:48 PM
>> *Subject: Tracking Hurricanes
>> *
>> *Does anyone know how to get the maximum values of vorticity of a
>> domain?
>> (the value, lat and lon).I need the positions in order to track a
>> hurricane.
>> *Thanks in advance
>> *
>> *Arturo Caracas
>> *Atmospheric Sciences, México.
>>
>
> _________________________________________________________________
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--
********************************************************************
Charles Seman charles.seman at noaa.gov
U.S. Department of Commerce / NOAA / OAR
Geophysical Fluid Dynamics Laboratory voice: (609) 452-6547
201 Forrestal Road fax: (609) 987-5063
Princeton, NJ 08540-6649 http://www.gfdl.noaa.gov/~cjs/
********************************************************************
"The contents of this message are mine personally and do not reflect
any position of the Government or NOAA."
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