[ncl-talk] ncl-talk Digest, Vol 135, Issue 22

[Mary Barth]

Hi Negin,

For doing the same thing as you, I have found the model level by using 
the WRF height array ("z") that you can get from wrf_getvar routine.

It is also possible to create an output file from WRF-chem of variables 
along a flight track. Here is some more info:
“Tracking”  output:  vertical  profiles  of  prescribed meteorological  
and  chemical
species  at  a  set  of  prescribed  times  and  horizontal coordinates  
are  written  to  a
special  output  file,  wrfout_track_d<nn>.    The  namelist variable  
track_loc_in  is  a
count  of  the  track  locations  and  must  be  set  to  a positive  
value  otherwise  the  default
setting  of  zero  will  result  in  no  track  output  of  any 
variables.    Times  and  locations
must  be  specified  in  the  file  wrfinput_track.txt(  see example  
below).  Meteorological
variables  z,  p,  t,  u,  v,  w,  alt,  qcloud,  qrain,  qice, qsnow,  
qgraup,  and  qvapor  are  output
if  track_loc_in  is  non-­zero.    Chemical  species concentrations  
may  also  be  output  if
both  namelist  variables  track_chem_num  and  track_chem_name are  
set.    The  total
number  of  chemical  species  to  output  must  be  <=  100.

As  an  example  the  following  namelist  settings  will  output the  
default  meteorological
variables  and  co  and  o3  species  concentrations  at  the  two 
times  and  locations
specified  in  the  wrfinput_track.txt  file  :

&domains
track_loc_in  =  2,
/
&chem
track_chem_num  =  2,
track_chem_name  =  ‘co’,  ‘o3’,
/

The  following  two  lines  comprise  the  contents  of  the  ascii 
input  file
wrfinput_track.txt:

2010-­08‐10_00:12:00  41.450  -­87.300
2010‐08‐10_00:36:00  41.510  -­87.390

This  will  result  in  the  indicated  variables  being  output to  
wrfout_track_d01  at  the
times  00:12:00  UTC  and  00:36:00  UTC  on  August  10,  2010  at the  
grid  points  nearest
to  the  points  (41.450, -­87.300)  and  (41.510, -­87.390). Note  
that  the  tracking  tool
does  not  interpolate  in  time.  The  indicated  output  times need  
to  be  given  in
multiples  of  model  time  steps  else  no  output  is  produced.
The  exact  Fortran  format  for  the  lines  in  the  file 
wrfinput_track.txt  is
(A19,1X,F7.3,1X,F7.3)  and  the  horizontal  coordinates  are ordered  
for  latitude,
longitude  with  standard  WRF  conventions  wherein  south latitudes  
and  west
longitudes  are  negative.

This information is from 
http://www.acd.ucar.edu/wrf-chem/MOZCART_UsersGuide.pdf

-- Mary Barth

On 2/17/15 12:00 PM, ncl-talk-request at ucar.edu wrote:
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Mon, 16 Feb 2015 23:45:34 -0600
> From: Negin S <negin513 at gmail.com>
> Subject: [ncl-talk] flight pathway data
> To: Ncl Talk <ncl-talk at ucar.edu>
> Message-ID:
> 	<CAJpVDhqVPP-5sXWZ2saDg4vpE4OxcWK8LcN7nwgk_gtRN99X7Q at mail.gmail.com>
> Content-Type: text/plain; charset="utf-8"
>
> Hi Everyone!
>
> Recently I am working on extracting data along a flight pathway.
>
> I used the following for figuring out grid index of flight data across its
> pathway:
>
> nm = getind_latlon2d (lat2d,lon2d, lat, lon)
>
> do k=0,dimsizes(lat)-1
>       n = nm(k,0)
>       m = nm(k,1)
> end
>
> but I also need some help calculating the layer number based on flight
> altitude and time step based on flight time.
> I could not find any example for extracting data along flight pathway.
>
> Basically what I wanted to do is to extract data along flight pathway from
> model output(i.e. wrf-chem output) and write all the variables from model
> in a txt file.
>
> I highly appreciate all your helps.
>
> Best Regards,
> Negin

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