[gradsusr] data not in GRIB format

[Huddleston, John]

Hao,

You are welcome. 

The (24.828,100.01) is the lower left corner of your CMAQ grid. I simply dumped the x,y data, sorted it, and found the point.

95.969 is the longitude of your upper left corner and 131.2617 is the longitude of your upper right corner. Take the difference and divide by 94 to get the x delta.

Similarly, take the difference between your lower and upper latitude and divide by 67 to get the y delta.

John Huddleston, PhD

From: Hao He [mailto:haohe.umcp at gmail.com] 
Sent: Friday, May 07, 2010 1:24 PM
To: Huddleston, John
Subject: Re: [gradsusr] data not in GRIB format

John,
   Thanks a lot! It looks very nice. Can you tell me how to calculate the latref (24.828N), lonref(100.01), xdef and ydef? I have another nested domain, and I want to go through the process.

Best

Hao
On Fri, May 7, 2010 at 3:19 PM, Huddleston, John <Huddleston at cira.colostate.edu> wrote:
Hao, attached is an image from your data file using

 d ave(so2,t=1,t=25))

 where the control file is

dset ^SO2_CHINA_D1.ncf
dtype netcdf
title Vertically integrated atmos chem/aerosol vbles
pdef 94 67 lcc 24.828 100.01 1 1 30 60 113.7 30000 30000
undef -9999
xdef 94 linear  95.769    0.3659
ydef 67 linear  24.828    0.2644
zdef 34 linear 1 1
tdef 25  linear 00:00Z20apr2006 1hr
vars 3
LAT=>lat  1 t,z,y,x Latitude
LON=>lon  1 t,z,y,x Longitude
SO2=>so2  1 t,z,y,x Sulfur Dioxide
endvars
 
I don't know your data as well as you do; however, it appears to plot OK.
 
What do you think is the problem?
 
John Huddleston, PhD
 
From: Hao He [mailto:haohe.umcp at gmail.com] 
Sent: Friday, May 07, 2010 12:26 PM
To: Huddleston, John

Subject: Re: [gradsusr] data not in GRIB format
 
John,
   I created a file only with SO2 data. It contains 34 layers and 25 time frames. Please see attached file. I also attach one snapshot by ncview. 

Hao
On Fri, May 7, 2010 at 2:01 PM, Huddleston, John <Huddleston at cira.colostate.edu> wrote:
Hao
 
Put out a dataset for me to download. All I have is that one latitude longitude file.
 
What doesn't happen?  Where is the data plotted?
 
John
 
John Huddleston, PhD
 
From: gradsusr-bounces at gradsusr.org [mailto:gradsusr-bounces at gradsusr.org] On Behalf Of Hao He
Sent: Friday, May 07, 2010 11:11 AM

To: GrADS Users Forum
Subject: Re: [gradsusr] data not in GRIB format
 
John,
   I use your template to open the file. But it is not right. Please have a look at my .ctl file.

dset ^EMIS_CHINA_D1.ncf
title INTEX-B SO2 emission
undef -9999
pdef 94 67 lcc 34.8 113.7 1 1 30.0 60.0 113.7 30000 30000
xdef 94 linear 95.769 0.3659
ydef 67 linear 24.828 0.2644
tdef 25 linear 00:00Z03APR2008 1HR
zdef 34 linear 1 1
dtype netcdf
vars 1
SO2=>so2 0 t,z,y,x Sulfur Dioxide
endvars

Best

Hao
On Fri, May 7, 2010 at 12:06 PM, Huddleston, John <Huddleston at cira.colostate.edu> wrote:
Hao,
 
Based on the information you sent, here is a representative control file to plot your (COL,ROW)=(94,67) grid.
 
dset ^YourFile.ncf
dtype netcdf
title Vertically integrated atmos chem/aerosol vbles
pdef 94 67 lcc 24.828 100.01 1 1 30 60 113.7 30000 30000
undef -9999
xdef 94 linear  95.769    0.3659
ydef 67 linear  24.828    0.2644
.
 
 
John Huddleston, PhD, PE
 
 
From: gradsusr-bounces at gradsusr.org [mailto:gradsusr-bounces at gradsusr.org] On Behalf Of Hao He
Sent: Friday, May 07, 2010 8:43 AM

To: GrADS Users Forum
Subject: Re: [gradsusr] data not in GRIB format
 
John,

   I get the WRF WPS projection information as following:

e_we              =  98, 118,
 e_sn              =  70,  103,
 geog_data_res     = '10m','2m',                
 dx = 30000,
 dy = 30000,
 map_proj = 'lambert',
 ref_lat   =  34.8,
 ref_lon   = 113.7,
 truelat1  =  30.0,
 truelat2  =  60.0,
 stand_lon =  113.7,

My key point here is : CMAQ domain is a little bit smaller than WRF domain because we eliminate the outside columns and rows to diminish lateral effects. So my WRF domain has 98*70 grids while my CMAQ domain has 94*67 grids.

so the question is: how to set (isize, jsize) and (iref, jref) in pdef variable? I am confused.

Best

Hao
 

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