Experiment title 
: ACCESS-CM2 tropical Atlantic warming experiments
Summary : This project uses pacemaker-style experiments with ACCESS-CM2 to investigate how tropical Atlantic variability influences the Pacific warming trend and decadal variability.
Scientific motivation:
The discrepancy between the ‘La Nina-like’ Pacific warming pattern in observations and the ‘El Nino-like’ pattern simulated by most models, including ACCESS-CM2, is one of the major unresolved issues in the current generation of climate models. This complex issue is thought to be the result of one or more factors, including model responses to aerosols, oceanic ‘tunnel’ or ‘thermostat’ mechanisms, and tropical inter-basin interactions. This project aims to investigate one of these factors, namely how tropical Atlantic variability impacts the Pacific warming trend. It builds on previous pacemaker-style experiments run under piControl conditions, adding Historical forcing from the ACCESS CM2 CMIP6 ensemble.
Experiment Name : atl_trend_no_var_cm2
People : Zoe Gillett, Christine Chung (@ctychung), and Ghyslaine Boschat (@gab563), in collaboration with colleagues in NESP.
Model: ACCESS-CM2
Configuration: Historical partially coupled (or pacemaker-style) experiments.
Initial conditions: Simulations will be branched from year 1950 of the CMIP6 ACCESS-CM2 Historical runs: bm652, cd659, cd884, cj368, cj454, cj590, cm302, and cm303.
Run plan: 65 years per ensemble member (1950-2014), with 8 ensemble members in total.
Simulation details: Eight partially coupled historical experiments will be run in which tropical Atlantic SSTs are nudged toward the ensemble-mean ACCESS-CM2 historical SST trend (1950-2014) superimposed on the early 20th century climatology (1900-1949). This design isolates the effect of the observed Atlantic warming trend while suppressing internal variability in that region. We intend to investigate the impact of suppressing Atlantic variability on Pacific decadal variability, and the Pacific warming trend, under Historical forcings.
Total KSUs required : ~2.5 MSU (8 members × 65 years × 5.5 KSU per year).
Total storage required : None (output will be stored directly in another project).
Storage lifetime : Next 2 years.
Long term data plan : Transfer model output to MDSS.
Outputs: Monthly atmosphere and ocean variables.
Restarts: Restarts will be discarded.
Related articles:
Analysis: TBC.
Conclusion: TBC.