Output Emissions collection with lev positive up

[lizziel]

GCHP has always output the emissions diagnostic collection with levels inverted relative to all other diagnostic collections. Most emissions are 2D so this is not relevant for most emission outputs. However, for 3D emissions the convention difference is a pain for post-processing. It also can be a source of error if users are not aware of the difference from other diagnostics.

The lev positive down convention for HEMCO diagnostics originated in its use in GEOS which always stores and outputs variables with that convention. Changing it to lev positive up should be a straightforward change. The existing code for lev positive down should be kept but put into a MODEL_GEOS cpp ifdef.

[lizziel]

This feature request is somewhat related to:

• GCHP issue: [BUG/ISSUE] Incorrect or missing positive attribute in output lev dim #112
• MAPL feature request: Feature request: configurable lev positive attribute for History files GEOS-ESM/MAPL#914

[lizziel]

If feature request GEOS-ESM/MAPL#914 is implemented as proposed then no work would actually need to be done for this feature request beyond changing HISTORY.rc to specify up for Emissions collection. No changes to HEMCO would be required.

[lizziel]

Specifying lev positive up or down in history files is now possible in MAPL 2.8.3. When this will go into GCHP is still TBD.

[lfreese]

Hi @lizziel --Just checking in to make sure I've understood the relevant threads to this correctly (followed issues #112 and #10 here): if I'm using v 13.2.1, GEOSChem.Emissions collection output will have the surface at lev = 72, and toa at lev = 1; whereas all other collections (eg: SpeciesConc, AerosolMass, etc) have surface at lev = 1 and toa at lev = 72?

[lizziel]

Yes, that is correct! The restart file is also flipped relative to the other diagnostics.

[lizziel]

This update is being moved to the 14.1 release.

[lizziel]

I wonder if we should push this to 15.0 since it will break GCPy and maybe is more appropriate for a major release.