Experiment Proposal: ACCESS-ESM1.5 Miocene 3xCO2 run

Experiment title: ACCESS-ESM1.5 Miocene 3xCO2 run

Summary: Running a 500-year simulation of the Miocene climate optimum with 3xCO2 forcing. Using paleogeography boundary conditions of Burls et al (2021), reconfigured to the ACCESS-ESM1.5 ocean-atmosphere-land grids.

Scientific motivation: The Miocene Climate Optimum (14.7-17 million years ago) represents an important analogue of future climate change, since it had relatively high CO2 (~500-800ppm), and strong polar amplification. End of 21st Century projections of CO2 forcing are closely aligned with Miocene CO2 levels.

I am already running a similar Miocene 3xCO2 simulation with the GFDL CM2.1 model, which has been spun up already for 2500 years. We will use this simulation (lower resolution and cheaper to run), to give us a faster approach to equilibrium.

The results will contribute to the Miocene Model Intercomparison Project (MioMIP), and also serve as a geologically constrained test of climate sensitivity for the ACCESS-ESM1.5 model.

Experiment Name: mio_c3_v1

People: David Hutchinson, in collaboration with Katrin Meissner, Laurie Menviel and others.

Model: ACCESS-ESM1.5

Configuration: ACCESS Hive wiki of input conditions and restart procedures and accompanying github repository to generate input files.

Initial conditions: Temperature-salinity restart files derived from ~year 2500 of a GFDL CM2.1 simulation based on same paleogeography boundary conditions.

Run plan: 500 year spinup of 3xCO2 Miocene run.

Simulation details: Will be started in January 2024, and run in Q1.

Total KSUs required: 485 KSU (500 x 0.975 KSU)

Total storage required: Approx 5 TB, temporary storage to be archived elsewhere.

Outputs: to be updated
Restarts: to be updated
Related articles: Burls et al (2021)

Analysis: to be updated