grid domain

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559806
Posts: 14
Joined: August 18th, 2022, 12:27 pm
Registered HYSPLIT User: Yes

grid domain

Post by 559806 »

Hello users, Can anyone tell how to restrict grid domain to a smaller area and not get the warning: metpos: off spatial domain of all grids? I am doing dispersion calculation of plume but it gets cut off as grid is defined to a smaller area. Is there any solution to this? I am in need of help, please respond
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alicec
Posts: 411
Joined: February 8th, 2016, 12:56 pm
Registered HYSPLIT User: Yes

Re: grid domain

Post by alicec »

The concentration grid is user defined in the CONTROL file or through the GUI.
See here
https://www.ready.noaa.gov/hysplitusersguide/S313.htm

It looks like you need to increase the span of your concentration grid to cover a larger area.
559806
Posts: 14
Joined: August 18th, 2022, 12:27 pm
Registered HYSPLIT User: Yes

Re: grid domain

Post by 559806 »

Yes sir. I am suppose to set grid to a smaller area (A CITY) and not a larger area. I wanted to find a way in which if coarse grid is set, the particles do not go out of grid and dispersion is restricted to a smaller area. Is there a way?
alicec
Posts: 411
Joined: February 8th, 2016, 12:56 pm
Registered HYSPLIT User: Yes

Re: grid domain

Post by alicec »

I'm not sure I understand what you want to do.

You can set several concentration grids. So you can have a smaller fine resolution one around your release area and
then a larger coarser one that covers a larger area.

But it sounds like you want the model to stop the particles from moving outside of your area of interest?
If that is correct, can you explain the physical reasoning behind doing such a thing?
If you need a really fine resolution that takes into account the effect of buildings, street canyons etc in the dispersion
then you will need an urban scale model which takes as input the actual topography of the city as well as some simulation
that simulates the wind field at those scales.
559806
Posts: 14
Joined: August 18th, 2022, 12:27 pm
Registered HYSPLIT User: Yes

Re: grid domain

Post by 559806 »

I did not see the notification, extremely sorry for replying late. The reason I wanted to restrict the area was to view clearly how city of Lahore, Pakistan was getting affected from brick kilns emission. As you see in output, whole area of source location (encircled) is blue and there is no variation of concentration (colors). I guess this is not possible.
Sir can you please tell me how to convert concentration output file to csv file? Thank you in advance.
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alicec
Posts: 411
Joined: February 8th, 2016, 12:56 pm
Registered HYSPLIT User: Yes

Re: grid domain

Post by alicec »

This looks like it is a plotting issue.
There are a few choices here.

1. You can continue to use the plotting program provided (concplot)
concplot has 38 options for customizing plots. You can set the contour levels, colors etc.
You can also change the domain size to some extent. The HYSPLIT tutorial has some examples throughout.
https://www.ready.noaa.gov/hysplitusers ... m#concplot
https://www.ready.noaa.gov/HYSPLIT_Tutorials.php

2. If you want to convert the cdump files to ascii you can use the con2asc program.
https://www.ready.noaa.gov/hysplitusers ... tm#con2asc

3. If you use python you can read the cdump files into an xarray DataSet using the monetio package.
https://github.com/noaa-oar-arl/monetio
559806
Posts: 14
Joined: August 18th, 2022, 12:27 pm
Registered HYSPLIT User: Yes

Re: grid domain

Post by 559806 »

Thank you sir for your kind and immediate responce
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