Issues are ordered from most recent to least recent.

Topography file error

Date of report: February 2023
Title: Topography file error 2022
Issue: Regional refined topography was in the incorrect location/orientation
Model tags affected: NCAR_Topo_2_0_1 files for regional refinement. An erroneous topography file was specified for use when creating variable resolution grids between April 2022 and Jan 2023. 
Model response: Gravity waves impacted, incorrect transport, chemistry fields displaced
Fix: Reprocess topography and re-run model simulations. If you created your own grid during that period please checkout the updated code at:  https://GitHub.com/NCAR/Topo and recreate your topography file for your grid and re-run any simulations. To check if your topography file has this error, plot ANGLL vs ANGLX.  In a "good" topo-file these variables should have large differences. In a "bad" file they will be very close everywhere.
More information: AMWG Github issue 213

Advection error in SE

Date of report: 2022
Title: Advection error in Spectral Element dycore
Issue: Spurious vertical transport was found over steep topography.  The issue is described in this AMWG GitHub issue #151. 
Model tags affected: ???
Model response: ???
Fix: For CESM2.2.0 source code the correction is, in src/dynamics/se/dycore/prim_advance_mod.F90 (at l.578), replace:

                 elem(ie)%derived%dpdiss_ave(i,j,k)=elem(ie)%derived%dpdiss_ave(i,j,k)+&
                      rhypervis_subcycle*eta_ave_w*elem(ie)%state%dp3d(i,j,k,nt)

with:

                 elem(ie)%derived%dpdiss_ave(i,j,k)=elem(ie)%derived%dpdiss_ave(i,j,k)+&  
                      rhypervis_subcycle*eta_ave_w*(elem(ie)%state%dp3d(i,j,k,nt)-dp3d_ref(i,j,k,ie))

More information: The correction for current development tags is provided in CAM github issue #633. 
Update Nov 1, 2022: Please see additional code fix described in CAM github issue #678.

CLM time-averaging bug affecting MEGAN emissions

Date of report: 8 July 2022
Title: Incorrect calculation of MEGAN emissions
Issue: A bug has been identified in CLM that probably has affected most MUSICAv0 simulations. 
Model tags affected: MEGAN emissions, especially in regional refined simulations. MUSICAv0 simulations before July, 2022.
Model response: This bug results in erroneous calculations of the time-averaged (1-day, 10-days) temperature, photon flux, and other variables, that are used in the MEGAN biogenic emissions calculation (and elsewhere in CLM).
Fix: Added a fix to accumulation code CTSM/src/main/accumulMod.F90
In general, Isoprene emissions are reduced with the bug fix.

More information: See discussion at the CTSM GitHub issue #1789. 

Chemistry mechanism bug

Date of report: 2021
Title: MPAN+M chemistry bug
Issue: In the TS1 and TSMLT1 chemistry mechanisms (compsets FCnudged, FCHIST, FWHIST, etc.) the MPAN+M reaction is not calculated because the user reaction refers to a reaction not in the mechanism (tag_MCO3_NO2 instead of usr_MCO3_NO2).  This error does not exist in the TS2 chemical mechanisms.
Model tags affected: Not in versions CESM2.1 and prior. Found in version CESM2.2, May 2021. Fixed in version CAM6_3_019.
Model response: Missing chemistry.
Fix: Update chemical mechanism from:

[usr_MCO3_NO2] MCO3 + NO2 + M -> MPAN + M
to:
[tag_MCO3_NO2] MCO3 + NO2 + M -> MPAN + M. ; 9.7e-29, 5.6, 9.3e-12, 1.5, 0.6

More information:  CAM GitHub issue #364 
Contact Louisa Emmons with any questions.