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geoschem / HEMCO

The Harmonized Emissions Component (HEMCO), developed by the GEOS-Chem Support Team.
https://hemco.readthedocs.io
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Incorrect handling of pressure unit in HEMCO standalone #277

Open yuanjianz opened 1 month ago

yuanjianz commented 1 month ago

Your name

Yuanjian Zhang

Your affiliation

WashU

What happened? What did you expect to happen?

Issue

HEMCO standalone, different from HEMCO within geos-chem, has a internal pressure unit of Pa instead of hPa (See geos-chem/GeosCore/hco_interface_gc_mod.F90)

Processed meteorological fields for MERRA-2 and GEOS-FP are separately in Pa and hPa.

Unlike geos-chem, HEMCO standalone does not have the automatic met-specific unit conversion in geos-chem/GeosCore/flexgrid_read_mod.F90

So pressure is mistakenly treated as Pa if using GEOS-FP(and GEOS-IT) to drive HEMCO standalone. Possibly making output emission field in kg/m2/s 1000 times smaller.

Related issues: #275

Workaround

Manually use a hPa2Pa scale factor of 100.0 in configuration.

But I also wish this can be addressed in a more natural manner like in GC-Classic and GCHP.

What are the steps to reproduce the bug?

use standard run directory creation script to run a HEMCO standalone instance with GEOS-FP

Please attach any relevant configuration and log files.

No response

What HEMCO version were you using?

standalone

What environment were you running HEMCO on?

Local cluster

What compiler and version were you using?

gcc 10.2.0

Will you be addressing this bug yourself?

Yes, but I will need some help

In what configuration were you running HEMCO?

Standalone

As what resolution were you running HEMCO?

all

What meterology fields did you use?

Other (please explain in additional information section below)

Additional information

GEOS-FP and GEOS-IT

lizziel commented 4 weeks ago

Thanks @yuanjianz for reporting this. I am curious if this means all of the offline emissions for GEOS-FP are incorrect since they are generated by using HEMCO standalone with the processed meteorology.

@yantosca, @msulprizio - do we know who generated the FP offline emissions?

yuanjianz commented 4 weeks ago

Hi @lizziel, I happen to have the codes for FP offline emissions. It seems BioVOC, soilNOx and seasalt are independent of pressure. Only dust is affected: https://github.com/geoschem/HEMCO/blob/3bd40ad84c46c36107d83b5353e57ce279b593f0/src/Extensions/hcox_dustdead_mod.F#L420-L421 I checked the dust offline emission codes. They are quite old and labeled v11.01 and the hemco_stanalone.x needs to be compiled together with GC-classic. In its HEMCO_sa_Config:

* PSFC /ExtData/GEOS_0.25x0.3125/GEOS_FP/$YYYY/$MM/GEOSFP.$YYYY$MM$DD.I3.025x03125.nc PS    $YYYY/1-12/1-31/0-23 C xy  hPa     * - 1 1

I check GEOS-FP dust emission and they seem correct. I am not quite sure if it is because old HEMCO is compiled with GC-Classic and it has the automatic unit conversion.

yuanjianz commented 4 weeks ago

I am opening this issue since I am updating our ancient offline emission codes to HEMCO v3.9.0.