Tier II: Aerosol hemispheric asymmetry fingerprint

[duncanwp]

Description

Evaluate the observable imprint of aerosol forcing via the NH–SH temperature asymmetry.

Specification

• Interhemispheric temperature contrast (NH − SH mean surface temperature) trend over 1950–1985
• Models should reproduce observed NH cooling tendency (or reduced warming relative to SH)
• Correct sign of associated tropical precipitation shift
• Compare against HadCRUT and Berkeley Earth
• Scored using CRPS framework

Required variables

tas, pr

Required simulations

historical

References

Protocol §Tier II — Aerosol hemispheric asymmetry

[duncanwp]

Proposed solution: extend ICONEval's cloud maps for hemispheric asymmetry

ICONEval's recipe_clouds_maps includes multi-obs AOD maps via MODIS and ESACCI references. This provides the spatial data needed for the hemispheric asymmetry fingerprint.

• Port the AOD map recipe with CMIP6 multi-model datasets
• Add a custom diagnostic script to compute the NH-SH aerosol asymmetry index from the spatial fields
• Compare model asymmetry against observed asymmetry from MODIS/ESACCI
• Could also be implemented in the Python pipeline using the existing od550aer benchmarking path

Phase: 3 (Tier II observational benchmarks) in the integration plan
ICONEval reference: recipe_clouds_maps.yml (multi-obs AOD maps)