Implementation of stratospheric injections of solid particles in WACCM6-CARMA

Stratospheric aerosol injection using solid particles is being explored as an alternative to the conventional use of sulfuric acid in solar radiation modification in modeling studies, aiming to address its limitations, such as suboptimal particle size distribution, stratospheric heating, and ozone depletion. Recent studies have suggested that materials like alumina, calcite, and diamond may offer reduced chemical and radiative side effects. However, these alternatives have only been evaluated in a single Earth system model to date: the SOlar Climate Ozone Links v4.0 (SOCOLv4).

Building on the specifications for incorporating solid particles into SOCOLv4, we implemented the injection of alumina, calcite, and diamond into the Whole Atmosphere Community Climate Model version 6 (WACCM6), coupled with the Community Aerosol and Radiation Model for Atmospheres (CARMA). We simulate annual injections of 5 and 25 Tg for each of the solid materials and compare the results to equivalent injections of accumulation-mode sulfuric acid aerosols. Our analysis focuses on the microphysical and radiative processes associated with each aerosol type, enabling a direct comparison with prior model studies and serving as a foundation for a potential Geoengineering Model Intercomparison Project testbed.