similar trajectories for varying heights and constant 2) starting level above ground

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sumit
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Joined: May 27th, 2016, 4:46 am
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similar trajectories for varying heights and constant 2) starting level above ground

Post by sumit » August 26th, 2016, 3:29 am

I am using Unified Model output (converted to GRIB2 format) to simulate trajectories.
I could able to successfully convert grib2 file to ARL format using “api2arl” utility. I checked the file and messages after running the hysplit but could not find any error.
I am facing following issues:
1) The trajectory plot shows similar trajectories for different heights.
2) starting level above ground of all trajectories is no varying i.e. constant

Kindly help me to sort these issues. I have attached the message and chkfile and trajplot.ps file for reference.
The control file details are as follows:
16 08 23 18
4
18.90 72.80 100
18.90 72.80 500
18.90 72.80 1500
18.90 72.80 3500
-240
0
500000
1
/gpfs4/home/sumit/HYSPLIT/back_frwd_traj/bkwd_traj/GRIB2_HYSPLIT/GRIB2/
final_DATA.ARL
/gpfs4/home/sumit/HYSPLIT/hysplit/trunk/working/
tdump_grib2

I tried to change the model name to "ecmwf" (as you see in attached files) but this also resulted in same plots (as attached).

Sumit
Attachments
MESSAGE.txt
(79.2 KiB) Downloaded 51 times
chkfile.txt
(137.68 KiB) Downloaded 56 times
trajplot.ps
(241 KiB) Downloaded 64 times

ariel.stein
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Joined: November 7th, 2012, 3:14 pm
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Re: similar trajectories for varying heights and constant 2) starting level above ground

Post by ariel.stein » August 26th, 2016, 8:53 am

The api2arl has not been tested for the Unified Model, but we will be glad to help you make it work.
From what I can infer from the information you sent me, It seems the vertical layers are shuffled. The api2arl needs to be customized for the particular meteorological dataset you are converting. So, you will need to check the vertical coordinates and the horizontal projection for the Unified Model and modify the api2arl program to read them accordingly.
We will be very interested in getting the modified code so we can incorporate it to our repository so other users can benefit from your development.

sumit
Posts: 2
Joined: May 27th, 2016, 4:46 am
Registered HYSPLIT User: Yes

Re: similar trajectories for varying heights and constant 2) starting level above ground

Post by sumit » August 27th, 2016, 12:34 pm

Thank you for your kind reply.
Would you please elaborate more about the changes I need to make or the section/s I need to modify

I could not understand the following lines
>It seems the vertical layers are shuffled.
>The api2arl needs to be customized for the particular meteorological dataset you are converting.
(I am using the similar dataset, as you can see in MESSAGE file. I do not think they are different from ECMWF. What are the changes you expect?)
The GRIB2 data, I am using has variables on pressure level and on regular lat/lon grid.

ariel.stein
Posts: 578
Joined: November 7th, 2012, 3:14 pm
Registered HYSPLIT User: Yes
Contact:

Re: similar trajectories for varying heights and constant 2) starting level above ground

Post by ariel.stein » August 29th, 2016, 3:49 pm

I am not familiar with the Unified Model's vertical coordinate system. However, from what I gathered from a quick search is that the UM uses a terrain-following height coordinate. You would first try to confirm what is the vertical coordinate you are dealing with. Then, you will also need to know what is the order in which the vertical data is saved in your meteorological file, so you can extract the vertical levels accordingly.
After your gather that information, you will need to modify the fortran code in order to reflect the type of vertical coordinate and the order of the data.

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