AERO process in Process Analysis

CMAQ Chemistry and Aerosols
1

Hi, all!

I have some questions about process analysis in CMAQ version 5.3.1.

I think ‘AERO’ process is meaning contribution of gas-phase chemical reaction.

But I confirmed that the minimum value of ‘AERO_ASO4I’ in my simulation represented negative value.

I want to know why negative value can be shown in AERO process.

And If my thinking (AERO process means gas-phase chemical reaction) is wrong, then how I can get contribution of gas phase chemical reaction in process analysis??

I hope that I get answers from you.

Thank you.

HyeonYeong Park

2

Hi HyeonYeong,

There was a bug in process analysis for aerosols introduced in v5.3. It is resolved in v5.3.3 – see Release Note 15 here (CMAQ/CMAQv5.3.3_bugfixes.md at 5.3.3+ · USEPA/CMAQ · GitHub).
Do you still get negative values with this corrected version?

Best wishes,
Ben Murphy

3

Hi, Dr. Murphy!

Thanks for your responses.

And I’m so sorry to answer about your responses too late… :joy:

I conducted a small test with revised three source code files (sciproc.F, pa_update.F, aero_subs.F) to confirm appearance of negative values from ‘AERO_ASO4I’.

Although, there is still negative values of ‘AERO_ASO4I’, its absolute value was getting smaller than that from original version of CMAQ v5.3.1.

Thanks to your help for solving the problem :slight_smile:

HyeonYeong Park