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Matthew Mizielinski edited this page Sep 29, 2022 · 4 revisions

UKESM1 ARISE experiments

The UKESM1 ARISE experiment explores the impacts of geoengineering via the injection of sulphur dioxide (SO2) into the stratosphere. The injections occur at four different latitudes: 15 degrees N & S and 30 degrees N & S, at an altitude of approximately 20 km.

The simulations are based on the medium-emissions CMIP6 scenario ssp245 (O'Neill et al. 2016) and cover the years 2035 to 2070. They form a 5-member ensemble with initial conditions taken from the corresponding five members of the ssp245 simulations upon which they were based.

There are three targets for the ARISE simulations (Kravitz et al., 2016; Richter et al., 2022):

  1. Annual, global-mean near-surface air temperature to be cooled down to, and then maintained at, 1.5 degC above the pre-industrial mean (the latter determined from the long-term mean of UKESM1's CMIP6 piControl simulation).
  2. The hemispheric temperature balance to be returned to and maintained at the same level as when the global-mean temperature was 1.5 degC above pre- industrial.
  3. Same as target (2) but for the average poles-tropics temperature difference.

Using a 5-member ensemble mean, a period in UKESM1's CMIP6 historical/ssp245 simulations was identified when the 20-year mean global temperature was 1.5 degC above pre-industrial. The temperature pattern during this period (2014-2033) was used to define targets (2) and (3) above.

The amount of SO2 injected at each location is adjusted annually by an algorithm which examines the temperature distribution in the previous year, compares it with the three targets descibed above, and adjusts the injection rate for the next year accordingly (Kravitz et al., 2016, 2017; MacMartin et al., 2017).

References

Kravitz, B., et al., Geoengineering as a design problem, Earth Syst. Dynam., 7, 469-497, doi:10.5194/esd-7-469-2016, 2016.

Kravitz, B., et al., First simulations of designing stratospheric sulfate aerosol geoengineering to meet multiple simulataneous climate objectives, J. Geophys. Res. (Atmos.), 122, 12616-12634, doi:10.1002/2017JD026874, 2017.

MacMartin, D. G., et al., The climate response to stratospheric aerosol geoengineering can be tailored using multiple injection locations, J. Geophys. Res. (Atmos.), 122, 12574-12590, doi:10.1002/2017JD026868, 2017.

O'Neill, B. C., et al., The Scenario Model Intercomparison Project (ScenarioMIP) for CMIP6, Geosci. Model Dev., 9, 3461-3482, doi:10.5194/gmd-9-3461-2016, 2016.

Richter, J., et al., Assessing responses and impacts of solar climate intervention on the Earth system with stratospheric aerosol injection (ARISE-SAI), EGUsphere [preprint], doi:10.5194/egusphere-2022-125, 2022.

UKESM1 ARISE data description

The UKESM1 data prepared for ARISE has been performed in a similar fashion to that for CMIP6; the variable definitions and standards are identical, but a few elements of the controlled vocabularies used for CMIP6 have been altered;

  • MIP Era : set to ARISE
  • Activity id : set to ARISE
  • Experiment id: set to arise-sai-1p5
  • License: Data from the new experiment is made available under the UK Open Government License, equivalent to the Creative Commons CC-BY 4.0.
  • Tracking id: this global attribute in the files simply has a unique identifier, there is no relationship with the handle service as in CMIP6

Variables

See List of variables page

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