Does old emission input data work with new version of CMAQ-5.3.1?

CMAQ
1

Hi everyone,

I am a new learner of CMAQ and i use the latest CMAQ-5.3.1 version. I am now rerunning one of my senior’s simulation and got the emission input data directly from her. She is using CMAQ-5.0.2 and SMOKE-4.0. So the emission data i got is generated using SMOKE-4.0 and the chemical mechanism is cb05. But in CMAQ-5.3.1 the cb05 chemical mechanism is updated to cb6. Could i use the emission inventory directly? Do i need to regenerate the emission input data myself because of the update of the chemical mechanism?

Lin

2

Hi Lin,
There are multiple things to consider, but you should be able to create a first order mapping using the DESID emission control file.

For aerosol purposes:

  1. naphthalene should ideally be split from XYL. This is minor. See https://www.airqualitymodeling.org/index.php/CMAQv5.1_VOC_Emission_Updates
  2. SOAALK should ideally be considered. This is minor. See https://www.airqualitymodeling.org/index.php/CMAQv5.1_VOC_Emission_Updates
  3. a-pinene needs to be split from other monoterpenes (TERP) if using aero7 (highly recommended over aero6). See require emission updates here: https://github.com/USEPA/CMAQ/blob/master/DOCS/Release_Notes/aero7_overview.md. This update is important for PM2.5 performance and failing to split out APIN will result in overestimates in PM2.5 (particularly in vegetated locations).

This does not cover updates that may be needed for gas-phase chemistry (Ramboll/Environ may have documentation as well as the CMAS wiki covering updates since v5.0.2).

Havala

3 Likes
3

Thank you sooo much!

4

Hi Lin,

Did you solve this problem? I also meet this and try to mapping the old emission input to new version CMAQ.

Jason

5

Hi Jason,

Can you confirm what version of CMAQ you are using, and what mechanisms you are tying to map from and to?

Best wishes,
Ben Murphy

6

Hi Ben,

I use CMAQ5.3.1 and CMAQ5.2.1, and try to map emission of cb5ae5 to cb6ae6 or cb7ae7. I tried to find the coefficients to convert each old emission species into new emission species, but failed. Have you converted the old emission into new emission species?

Thanks a lot,
Jason

7

Hi Jason,

Please see the attached Emission Control File which should roughly map cb05tucl_ae5_aq to the cb6r3_ae7_aq mechanism. The file format itself should be compatible with CMAQv5.3.1.

There still may be hiccups. I made suggestions on how to solve potential crashes in comments within the file. Let me know if you get stuck. Be sure to change the extension from .txt to .nml.

EmissCtrl_cb05ae5_to_cb6r3_ae7_aq.txt (30.5 KB)

-Ben

3 Likes
8

Hi Ben,

Is there an equivalent file to map cb6_ae7 to cb6_ae6?

-Kyan

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I think you just need to add both APIN and TERP from the cb6_ae7 file to TERP in cb6_ae6. I believe everything else should be the same. @Havala.Pye may confirm this.

Best,
Ben

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The three options for mapping the monoterpenes in ae6 to ae7 mechanisms are under “Required Emission Updates”: CMAQ/DOCS/Release_Notes/CMAQv5.3_aero7_overview.md at 5.3.3 · USEPA/CMAQ · GitHub

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Thank you both for your responses, this is super helpful.

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Hi Havala, I am specifically hoping to map from ae7 to ae6 with the species APIN, GLY, GLYD, ISPD, IVOC, MGLY, NMOG, and PACD that aren’t found in ae6. From what I understand, APIN can be mapped to TERP in ae6, NMOG can be disregarded, and ISPD is likely insignificant in magnitude. How would I map the other species from ae7 to ae6 to run WRF-CMAQ?

Thanks for your help!
Kyan

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IVOC doesn’t appear in the DESID control file or GC.nml for cb6r3_ae6_aq indicating it is not used (perhaps diagnostic). APIN should be added to TERP from ae7 and the sum used as TERP in ae6 (Release_Notes link above). I see GLY, GLYD, ISPD, PACD, and MGLY in cb6r3_ae6 (CMAQ/CCTM/src/MECHS/cb6r3_ae6_aq/mech_cb6r3_ae6_aq.def at 5.3.3 · USEPA/CMAQ · GitHub) so those should map 1:1.

1 Like
14

This is very helpful, thank you!