ARISE-SAI scripts

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. This 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. 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.