Experiment title 
: Aerosol precursor emission sensitivity simulations with ACCESS-AM2 N96 (9 years)
Summary : ACCESS-AM2 is shown to underestimate aerosol populations crucial for cloud processes, particularly in the Southern Ocean. With cloud feedbacks in the Southern Ocean contributing to the largest source of uncertainty in equilibrium climate sensitivity, understanding the interactions between aerosol, clouds and radiation is crucial. Different magnitudes of aerosol precursor emissions over sea ice regions are tested to reveal modelled cloud processes sensitivity to these emissions. I have completed a control, low perturbation simulation and the first half of a medium perturbation simulation; with a further simulation planned (high perturbation run). Simulations are AMIP-style runs from 01/2016 - 05/2024 (2015 as spin-up), with monthly outputs. I also plan to run shorter periods with daily output targeted to match temporal periods with ship and field campaigns in the Southern Ocean and coastal Antarctica.
Scientific motivation: Southern Ocean and coastal Antarctic Cloud Condensation Nuclei (CCN) are underestimated in ACCESS-AM2 simulations - with the largest underestimation for Antarctic sea ice regions. We examine whether a sea ice source of aerosol may improve modelled cloud and radiation.
Experiment Name : am2aerosol
People : Alanah Chapman, Sonya Fiddes, Matt Woodhouse, Yi Huang, Robyn Schofield
Model: ACCESS-AM2
Configuration: GA7.1 N96 UM10.6 CABLE AMIP historical (no LUC) with aerosol fixes and ozone redistribution, global, PMO on, DMS 1.0, H22 DMS
Initial conditions:
Run plan: N96 resolution
- Medium perturbation run: half length simulation with monthly output (already completed the first few years) - 5.5 years remaining
- High perturbation run: full length simulation with monthly output - 9 years
- Daily output simulations: total ~1 year
Simulation details: 01/2016, global
Total KSUs required : 190 KSU
Total storage required : No storage required
Outputs: /scratch/q90/ac9768/cylc-run/u-dt947/share/data/History_Data/
Restarts: /scratch/q90/ac9768/cylc-run/u-dt947/share/data/History_Data/
Related articles: ACP - The ACCESS-AM2 climate model underestimates aerosol concentration in the Southern Ocean; improving aerosol representation could be problematic for the global energy balance - control run configurations described in this paper (PMO + H22) with the simulation runtime changed here to 01/2016-05/2024. Fiddes et al also describe the ACCESS-AM2 underestimations in aerosol number concentration compared to observations, and comment on a potential cause (underestimation of sea ice associated aerosol precursor emissions).
Analysis:
Conclusion: