Assessing Responses and Impacts of Solar climate intervention on the Earth system with Stratospheric Aerosol Injection (ARISE-SAI)

Solar climate intervention using stratospheric aerosol injection is a proposed method of reducing global mean temperatures in order to avoid the worst consequences of climate change. Assessing Responses and Impacts of Solar climate intervention on the Earth system with Stratospheric Aerosol Injection (ARISE-SAI) is a set of simulations carried out with the Community Earth System Model, version 2 with the Whole Atmosphere Community Climate Model, version 6 (CESM2(WACCM6)) that aims at simulating a plausible deployment of solar climate intervention of stratospheric aerosol injection to enable community assessment of responses of the Earth system. The first set of simulations introduce stratospheric aerosol injection at ~ 21 km in simulated year 2035, called ARISE-SAI-1.5, utilize the middle-of-the-road SSP2-4.5 emission scenario,, and keep global mean surface air temperature near 1.5°C above the pre-industrial value. Sulfur dioxide injections in the ARISE-SAI-1.5 simulations are placed at four injection locations (15°S, 15°N, 30°S, 30°N) into one grid box at 180° longitude, and midpoint altitude of 21.6 km. The injection amount at each latitude is specified annually by a “controller” algorithm (MacMartin et al. 2014, Kravitz et al. 2017) that was used in the Stratospheric Aerosol Geoengineering Large Ensemble (GLENS) project. This strategy ensures that the global mean surface temperature (T0), north-south temperature gradient (T1), and equator-to-pole temperature gradient (T2) remain close to ~ 1.5°C above the pre-industrial value throughout the simulation.

ARISE-SAI-1.5 simulations include extensive output for the atmospheric, land, ocean and sea-ice model components. All model output for the simulations is in NetCDF format. All variables are in time-series format, with one variable per file. 3-dimensional atmospheric output is on the original 70 model levels. Output consists of standard monthly mean CMIP6 output for the atmospheric, land, ocean, and sea-ice models. In addition, higher-frequency (daily averaged, 3-hourly averaged, 3-hourly instantaneous, and 1-hourly mean) output is available for the atmospheric model. A listing of all output variables is available (output follows member 006 - 010 of the reference simulations described below).

Further details about these simulations can be found in Richter et al. (2022).

Reference Simulations

There are 10 ensemble members of “reference” or SSP2-4.5 simulations (without climate intervention) with CESM2(WACCM6) that accompany the ARISE-SAI-1.5 simulations. A 5-member reference ensemble with CESM2(WACCM6) and the SSP2-4.5 scenario was carried out as part of the CMIP6 project for years 2015 - 2100. Surface temperature evolution and equilibrium climate sensitivity in these simulations are described in detail in Meehl et al. (2020). An additional 5-member ensemble of these simulations from years 2015 - 2069 was carried out with augmented high-frequency output for high-impact event analysis, as well as additional output for the land model to match the ARISE-SAI-1.5 simulations. A listing of all output variables is available.

Data Location

From NCAR's casper:

ARISE-SAI-1.5

/glade/campaign/cesm/collections/ARISE-SAI-1.5

CESM2(WACCM6) SSP-2.45

/glade/campaign/cesm/collections/CESM2-WACCM-SSP245

From NCAR Climate Data Gateway:

ARISE-SAI-1.5

https://doi.org/10.5065/9kcn-9y79

CESM2(WACCM6) SSP-2.45

https://doi.org/10.26024/0cs0-ev98

From Amazon/AWS Open Data Program:

https://registry.opendata.aws/ncar-cesm2-arise/

Usage Notes

We anticipate community analysis of various aspects of the Earth system of the ARISE-SAI-1.5 simulations. There is no obligation to inform the project leads and Community Liaison about the analysis you are performing, but it would be helpful in order to coordinate analysis and avoid duplicate efforts. The ARISE-SAI Analysis Registry shows past and ongoing analysis on the ARISE-SAI dataset. Please add your name to it if you're analyzing these simulations.

How to Acknowledge

When presenting results based on ARISE-SAI-1.5 in either oral or written form, please cite the overview paper (Richter et al. 2022) and cite the data DOIs: https://doi.org/10.5065/9kcn-9y79 and https://doi.org/10.26024/0cs0-ev98

Project Leads

• Jadwiga H. Richter [ jrichter@ucar.edu ]
• Daniele Visioni [ dv224@cornell.edu ]
• Douglas G. MacMartin [ dgm224@cornell.edu ]

Community Liaisons

For questions about the dataset and collaboration requests please contact:

• Mari Tye [ maritye@ucar.edu ]
• Daniele Visioni [ dv224@cornell.edu ]

Acknowledgements

We acknowledge support from the Polar Climate Working Group liaison, David Bailey. This material is based upon work supported by the National Center for Atmospheric Research, which is a major facility sponsored by the National Science Foundation under Cooperative Agreement no. 1852977 and by SilverLining through its Safe Climate Research Initiative. The Community Earth System Model (CESM) project is supported primarily by the National Science Foundation. Computing and data storage resources, including the Cheyenne supercomputer (doi:10.5065/D6RX99HX), were provided by the Computational and Information Systems Laboratory (CISL) at NCAR.