CMIP Ocean Variable Gaps and Calculation Issues (ACCESS-ESM1.6 Spin-up)

[rbeucher]

Several CMIP ocean variables required for CMIP6/CMIP7 outputs are either missing from the ACCESS-ESM1.6 December spin-up, or require non-trivial calculations that need review and validation. Some existing implementations also need clarification around robustness, frequency compatibility, and grid-resolution dependence.

This issue tracks missing inputs, questionable mappings, and calculation methods that need confirmation.

Missing Variables

@blimlim @MartinDix @chrisb13 @dougiesquire

• Missing temp_vdiffuse_diff_cbt for Oyr.ocontempdiff #198 - temp_vdiffuse_diff_cbt for Oyr.ocontempdiff
• Missing salt_vdiffuse_diff_cbt for Oyr.osaltdiff #199 - salt_vdiffuse_diff_cbt for Oyr.osaltdiff
• Missing frazil_3d for Omon.hfds #200 - frazil_3d for Omon.hfds
• Missing salt_submeso for Emon.osaltpsmadvect #201 - salt_submeso for Emon.osaltpsmadvect
• Missing salt_tendency for Oyr.osalttend #202 - salt_tendency for Oyr.osalttend
• Missing core daily variables: sea_level and surface_salt #203 - Daily variables: sea_level, surface_salt
• Missing total_volume_seawater for Omon.volo #206 - total_volume_seawater for Omon.volo

Calculation Issues / Frequency Mismatches

• masso: Missing total_mass_seawater in ESM1.6 spin-up #195 - masso: rho_dzt only available yearly, needed monthly
• Global-mean ocean variables at monthly frequency: rho_dzt only available yearly #209 - Global-mean variables (bigthetaoga, soga, sosga, thetaoga): same rho_dzt issue

Implementation Reviews Needed

• msftbarot: Drake Passage offset calculation needs review #196 - msftbarot: Drake Passage offset calculation looks fragile and resolution-dependent
• somint: Land masking clarification needed for depth-integrated S*rho #197 - somint: Land masking clarification needed
• Review calc_zostoga implementation #204 - calc_zostoga: Validation needed
• ocontemppsmadvect: Missing conversion factor in mapping #207 - ocontemppsmadvect: Missing conversion factor
• Review osaltpsmadvect implementation (related to salt_submeso) #208 - osaltpsmadvect: Implementation review

CMIP7 Updates

• CMIP7 cell methods and variable mapping review #205 - Cell methods and mapping review against CMIP7 spreadsheet

[dougiesquire]

Great work @rbeucher. It's straightforward to add the missing vars. Is there any discussion needed or shall I just prepare a PR?

[chrisb13]

Thanks @rbeucher, cc'ing @anton-seaice as he's now more directly involved in ESM1.6. Do reach out if you need anything else though.