Wrong rfac_oc, rfac_bc (aerosol growth factor) in BAM aero_model computed in interpolation

[jimmielin]

What happened?

Observe aero_model.F90 for BAM

CAM/src/chemistry/bulk_aero/aero_model.F90

Lines 833 to 837 in a1dcf88

	factor = (relhum(i,k) - table_rh(rh_l))/(table_rh(rh_u) - table_rh(rh_l))
	rfac_sulf = table_rfac_sulf(rh_l) + factor*(table_rfac_sulf(rh_u) - table_rfac_sulf(rh_l))
	rfac_oc = table_rfac_oc(rh_u) + factor*(table_rfac_oc(rh_u) - table_rfac_oc(rh_l))
	rfac_bc = table_rfac_bc(rh_u) + factor*(table_rfac_bc(rh_u) - table_rfac_bc(rh_l))

rfac_sulf and the computation for rfac_{oc,bc} are inconsistent. Looking at the intent of this code it is an interpolation table.

The rfac_oc, rfac_bc are wrongly using table_rfac_oc(rh_u) (note rh_u, not rh_l as base) - should be rh_l

What are the steps to reproduce the bug?

Observe the code above.

I think this will be an answer changing fix for compsets using BAM.

What CAM tag were you using?

cam6_4_183

What machine were you running CAM on?

CISL machine (e.g. derecho)

What compiler were you using?

Intel

Path to a case directory, if applicable

No response

Will you be addressing this bug yourself?

Any CAM SE can do this

Extra info

No response