Nested simulation "Do_Mixing" error

[laura-hyesung-yang]

Name: Laura Yang
Institution: Harvard University
GEOS-Chem version: v13.3.4

I'm running a 0.25 nested simulation. When I change the input.geos file to use the TURBDAY mixing scheme (Set use non-local PBL to True), I get the following error in my GC.log file:

WARNING: Negative concentration for species CH2I2 at (I,J,L) =           89          28          29
===============================================================================
GEOS-Chem ERROR:
-> at DO_TEND (in module GeosCore/mixing_mod.F90)
===============================================================================

===============================================================================
GEOS-Chem ERROR: Error encountered in "DO_TEND"!
-> at DO_MIXING (in module GeosCore/mixing_mod.F90)
===============================================================================

===============================================================================
GEOS-CHEM ERROR: Error encountered in "Do_Mixing"!
STOP at  -> at GEOS-Chem (in GeosCore/main.F90)
===============================================================================

I have boundary conditions and a 1-month spin-up file using non-local PBL mixing. I'm wondering if I should regenerate the BC and 1-month spin-up file using a full mixing scheme as well to avoid this error. When I use the non-local PBL mixing scheme in my 0.25 nested simulation, I don't encounter this error. Thank you!

[jimmielin]

Hi Laura, copying @mkelp and @fengx7 on this as well.

We have encountered issues with negative species concentrations in nested simulations dating at least back to v13. The negative artifacts appear to be present near the boundaries of the domain, possibly near or within the buffer regions.

[laura-hyesung-yang]

@jimmielin Thank you, Haipeng!

[yantosca]

@laura-hyesung-yang @jimmielin: I am now testing the fix in PR #1895, this could possibly fix your issue.

[laura-hyesung-yang]

@jimmielin @yantosca #1895 seems to fix this issue. I no longer get the "Do_Mixing" error after implementing the code change in #1895. Thanks, Haipeng and Bob!

[laura-hyesung-yang]

The issue actually persists with the #1895 fix.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. If there are no updates within 7 days it will be closed. You can add the "never stale" tag to prevent the Stale bot from closing this issue.

[jimmielin]

Bumping this error to prevent it from going stale. It might not be isolated to nested-grid full-chemistry simulations as we have observed this in nested-grid aerosol-only and WRF-GC simulations as well near domain edges. There might be something that has changed in the chemistry in the past few versions to introduce this instability.

[yantosca]

Tagged this issue with "never stale" to preserve it