Thanks Paula for the pointer! I've looked at the examples there, and I am
still struggling getting my observation data plotted. Any help from you or
the community is appreciated!
Here is the header info from my netcdf formatted observational data:
-------------------------------------------- header info of obs. data in
ncf ----------------------------------------
netcdf AQS_houly_O3.2010 {
dimensions:
TSTEP = UNLIMITED ; // (8760 currently)
DATE-TIME = 2 ;
LAY = 1 ;
VAR = 4 ;
COL = 593 ;
variables:
int TFLAG(TSTEP, VAR, DATE-TIME) ;
TFLAG:units = "<YYYYDDD,HHMMSS>" ;
TFLAG:long_name = "TFLAG " ;
TFLAG:var_desc = "Timestep-valid flags: (1) YYYYDDD or (2)
HHMMSS " ;
int STNID(TSTEP, LAY, COL) ;
STNID:long_name = "STNID " ;
STNID:units = "none " ;
STNID:var_desc =
"StationID:SiteCode_CountyCode_SiteCode(00_000_0000)
" ;
float LAT(TSTEP, LAY, COL) ;
LAT:long_name = "LAT " ;
LAT:units = "degrees " ;
LAT:var_desc = "Latitude for monitor station
" ;
float LON(TSTEP, LAY, COL) ;
LON:long_name = "LON " ;
LON:units = "degrees " ;
LON:var_desc = "Longitude for monitor station
" ;
float G_O3(TSTEP, LAY, COL) ;
G_O3:long_name = "O3 " ;
G_O3:units = "ppmV " ;
G_O3:var_desc = "Observed value, or MISSING < -999.0
" ;
// global attributes:
:IOAPI_VERSION = "$Id: @(#) ioapi library version 3.0 $
" ;
:EXEC_ID = "????????????????
" ;
:FTYPE = -1 ;
:CDATE = 2013303 ;
:CTIME = 234853 ;
:WDATE = 2013303 ;
:WTIME = 234853 ;
:SDATE = 2010001 ;
:STIME = 0 ;
:TSTEP = 10000 ;
:NTHIK = 1 ;
:NCOLS = 593 ;
:NROWS = 1 ;
:NLAYS = 1 ;
:NVARS = 4 ;
:GDTYP = 1 ;
:P_ALP = 0. ;
:P_BET = 0. ;
:P_GAM = 0. ;
:XCENT = 0. ;
:YCENT = 0. ;
:XORIG = 0. ;
:YORIG = 0. ;
:XCELL = 0. ;
:YCELL = 0. ;
:VGTYP = -9999 ;
:VGTOP = -9.999e+36f ;
:VGLVLS = 0.f, 0.f ;
:GDNAM = "LATLON " ;
:UPNAM = "" ;
:VAR-LIST = "STNID LAT LON
O3 " ;
:FILEDESC = "Obs. Query to IOAPI format for overlay plots
" ;
:HISTORY = "" ;
}
------------------------------------------------------------------------------------------------------------------------
As you can see, the file is time-stamped with concentration values for each
station which has associated lat lon values.
I am already able to plot the base map with model results using
"gsn_csm_contour_map", and I assume I will need to use "gsn_add_polymarker"
function to overlay the stations results to the map. I try the following
script in ncl for observation station:
---------------------------------------------------------------------------------
; read obs data in ncf format
o = addfile("AQS_houly_O3.2010.nc","r")
obs_spec = o->G_O3
obs_lat = o->LAT
obs_lon = o->LON
obs_spec@obs_lat = obs_lat
obs_spec@obs_lon = obs_lon
olat = dimsizes(obs_lat(:,0))
olon = dimsizes(obs_lat(0,:))
; plot polymarkers
polyres = True
polyres@gsMarkerIndex = 9
polyres@gsMarkerSizeF = 2.0
dum1 = gsn_add_polymarker(wks,plot,olon,olat,polyres)
-----------------------------------------------------------------------------------
but are getting the error:
fatal:Number of subscripts do not match number of dimensions of
variable,(2) Subscripts used, (3) Subscripts expected
It seems there is probably an easy fix, but I'd be more than happy to hear
from the experts whether I am in the right direction of creating the
observation overlay plots.
Thanks so much!
Chao-Jung
On Thu, Oct 31, 2013 at 8:54 AM, Paula Doubrawa <pdoubraw@indiana.edu>wrote:
> Hello,
>
> check out example 2 here
>
> http://www.ncl.ucar.edu/Applications/station.shtml
>
> station data colored according to a colorbar
>
> Paula
>
>
> On Thu, Oct 31, 2013 at 11:52 AM, Chao-Jung Chien <
> chaojung.chien@gmail.com> wrote:
>
>> Thanks Rick! Yes, I've looked at the polygons examples, and I can plot
>> the stations over the model results on a map. But what I really want is to
>> be able to show the actual values of the stations (rather than just
>> dots/markers) that use the same color scales as those for model results.
>> The model results are being shown using gsn_csm_contour_map. It seems
>> gsn_add_polymarker can only put the location markers on the plot, rather
>> than their own values?
>>
>> Again, any help on this is appreciated!
>>
>> Chao-Jung
>>
>>
>>
>> On Thu, Oct 31, 2013 at 6:20 AM, <brownrig@ucar.edu> wrote:
>>
>>> Hi,
>>>
>>> Have you checked out the examples at:
>>>
>>> http://ncl.ucar.edu/**Applications/polyg.shtml<http://ncl.ucar.edu/Applications/polyg.shtml>
>>>
>>> Example #3 in particular seems to come closest to what you want to do.
>>> The first half of that script deals with subsetting and manipulating data
>>> into an appropriate form; depending upon your data, you may likely be able
>>> to ignore that part. Everything from the comment "create plot" to the end
>>> would be relevent to creating your plot, with the real essense of it being
>>> those 8 lines after the comment "plot original data".
>>>
>>> Hope that helps...
>>> Rick
>>>
>>>
>>> On Wed, 30 Oct 2013 22:12:48 -0700
>>> Chao-Jung Chien <chaojung.chien@gmail.com> wrote:
>>>
>>>> Hi, sorry for the newbie question. I am trying to create a similar plot
>>>> like attached using NCL. Notice that the observational data are
>>>> presented
>>>> in diamonds, which are overlaying a gridded model results over a certain
>>>> region (map).
>>>>
>>>> Both observation and model data are already in netcdf file formats. The
>>>> observation data have the time-stamped values and associated lat/lon
>>>> info
>>>> for each station.
>>>>
>>>> Any existing NCL examples or pointers on how to create such an overlay
>>>> plot
>>>> are greatly appreciated.
>>>>
>>>> Thanks,
>>>> Chao-Jung
>>>>
>>>
>>>
>>
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>
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Received on Fri Nov 1 10:13:45 2013
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