Dear folks,
According to user pre-chem-src user guide, you should provide daily emission files to run WRF-chem. However, EDGAR-HTAP emission inventory is updated once a month.
My impression is that I should provide a emission file per month and set namelist in such a way that wrf-chem updates emission at the beginning of given month using auxinput5_interval_m=1800 (60 hr * 30 days). Did I get it right?
BTW, pre-chem-src user guide does not ask for turning chemistry on (chem_opt) before running convert_emiss.exe, but WRF-chem user guide does. Which one is correct?
Any help would be appreciated.
Hi Tariq Abdullah ,
You run prep-chem day by day.
From your prep_chem_sources.inp, I see you are considering fire emissions. This specific emission is daily. You probably have one file per day in your directory (Emission_data/fires_data/MODIS/Fires).
Therefore, if you will use WRF-Chem (as I see in your .inp), you will need a daily bb.bin file.
Attached I send a script that we use here to run prep-chem for one month (change the .txt to .sh to use). Basically, you set the end day (line 39) and the script will change the day on .inp and run the new day. Before using, check on line 53 if the .exe is the one you will use.
To run, it is only ./script...
Remembering that to convert the prep-chem emissions to WRF-Chem, you must use the convert_emiss tool from WRF-Chem v. 3.6, or before.
Prep-chem-src just process global inventories to serve as input in air quality models (WRF-Chem, for example). The program will use the EDGAR-HTAP emission inventory (if you select this option in prep_chem_sources.inp) and create daily emission files, according to the date you established.
The chemical mechanism used in this process is according to prep-chem-src compilation.
Willian Andreao thanks for you reply. I found Anthro_emiss utility more stright to create daily emission. It does not need convert_emiss.exe and produces emission for the entire study period whereas prep_chem requires rerun for each day according to the user guide. In addition, I also found that emission does not change day by day. But as you said, you are required to make it on daily and hourly basis just to make it readable for wrf chem.
Using Anthro_emiss could be kind of tricky when it comes to the modeling of PM10 and PM2.5. The problem is about the molecular weight which is not used for PM, but is mandatory in the antrho_emiss input file to read the HTAP data of PM10 and PM2.5.
Amir Hossein Nikfal Willian Andreao when we run wrf-chem for a month did we have to run prep_chem_src 30 times to complete all the required input files?? Because in prep_chem_src we give only the starting day/month/year.
Hi Tariq Abdullah ,
You run prep-chem day by day.
From your prep_chem_sources.inp, I see you are considering fire emissions. This specific emission is daily. You probably have one file per day in your directory (Emission_data/fires_data/MODIS/Fires).
Therefore, if you will use WRF-Chem (as I see in your .inp), you will need a daily bb.bin file.
Attached I send a script that we use here to run prep-chem for one month (change the .txt to .sh to use). Basically, you set the end day (line 39) and the script will change the day on .inp and run the new day. Before using, check on line 53 if the .exe is the one you will use.
To run, it is only ./script...
Remembering that to convert the prep-chem emissions to WRF-Chem, you must use the convert_emiss tool from WRF-Chem v. 3.6, or before.
Hi, Willian Andreao ,
How to assign the elevation details for industrial emissions provided in EDGAR-HTAP, by assuming the emission in the inventory to be stack emissions? For WRF-Chem simulations.
Thanks.
Hi Rakesh Kadaverugu
The EDGAR-HTAP emissions provided by prep-chem will be set just for the first layer. In WRF-Chem, the variable responsible for this is 'kemit' in &chem
In prep-chem user guide it is recommended to use:
kemit = 1, (surface emissions only)
io_style_emissions= 2,
emiss_inpt_opt = 1,
emiss_opt = 5,
Moreover, as prep-chem emission is speciate for RADM2 and GOCART, I am using
chem_opt = 303,
Thank you Willian Andreao for the answer. In which case, what would be the simplest method to create user defined emission inventory having point, area and line sources and having elevation details, suitable for WRF-Chem.
Thanks.
Rakesh Kadaverugu
I would like to suggest you to take a look on the Emission guide of WRF-Chem to find the best option for your data and domain:
https://ruc.noaa.gov/wrf/wrf-chem/Emission_guide.pdf
https://ruc.noaa.gov/wrf/wrf-chem/wrf_tutorial_2018/Anthro_emission.pdf
The WRF-Chem forum may be another source of information and discuss about emissions fields:
http://forum.mmm.ucar.edu/phpBB3/
Amir Hossein Nikfal I am a little confused here, I see that molecular weight is mandatory when using the anthro emiss utility but its not necessarily needed for PM estimation. Then how do go about doing PM 2.5/10 modelling using EDGAR HTAP data?. Do we have to multiply by the molecuar weight factor in the anthro_emiss namelist, since its not given in the EDGAR HTAP data and since the anthro emiss utility needs the molecular weight estimation for generating the emission input file. If so, do you know the molecular weight factor that needs to be multiplied?.
Ganesan Mk Currently I am not sure how to deal with this issue. If you managed to find any solution, please make us aware. But you can use prep_chem instead of anthro_emiss which is a bit more complicated, but does not have such issues.
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