Benchmark differences when verbose turned on

[lizziel]

Your name

Lizzie Lundgren

Your affiliation

Harvard University

What happened? What did you expect to happen?

I used the dev version of GC-Classic 14.5.1 with and without verbose on and found differences in output. This was a 1hr benchmark simulation. The differences are small but pervasive. We should expect no differences from changing verbose in geoschem_config.yml.

What are the steps to reproduce the bug?

Run benchmark simulation (dev 14.5.1) with and without verbose on. Then diff the OutputDir directories.

Please attach any relevant configuration and log files.

No response

What GEOS-Chem version were you using?

14.5.1 dev

What environment were you running GEOS-Chem on?

Local cluster

What compiler and version were you using?

gcc 10.2

Will you be addressing this bug yourself?

Yes

In what configuration were you running GEOS-Chem?

GCClassic

What simulation were you running?

Full chemistry

As what resolution were you running GEOS-Chem?

4x5

What meterology fields did you use?

GEOS-FP

Additional information

I plan to look into whether this is also the case for GCHP.

[yantosca]

Thanks @lizziel. I wonder if somehow we are toggling a function under verbose that changes model state? This could also be a problem in parallelization or initialization. Keep us posted!

[lizziel]

Yes. I would like to pick this up after the GC-Classic reproducibility updates go into 14.6 dev just in case there are any impacts there.