Future projections of the 2011 Super Tornado Outbreak under global warming and stratospheric aerosol injection

Abstract

Disasters associated with hazardous convective weather including severe thunderstorms, tornadoes, strong winds, large hail, and flooding, have been increasing in both frequency and cost. Previous studies using convection-permitting regional models show that climate change is likely to produce a future with fewer weak thunderstorms but more strong storms through increases in both convective available potential energy and convective inhibition. To potentially mitigate some of the threatening impacts of global warming, climate intervention strategies aiming to offset anthropogenic surface warming are receiving increased attention. One proposed approach is stratospheric aerosol injection (SAI), in which reflective aerosol particles would be injected into the upper atmosphere to decrease a small percentage of the total incoming solar radiation, thereby reducing future rates of warming. Little to no research has been conducted on the impacts from this possible strategy on severe weather using a convection-permitting model. We conduct novel simulations of the 2011 Super Tornado Outbreak using a 4-km version of the Weather and Research Forecasting (WRF) model to examine how this severe weather outbreak might be different in the future under two greenhouse gas emission scenarios with and without SAI. We find broadly that numerous parameters closely related to storm severity increase in a future with climate change, while parameter changes are minimal under climate change with SAI. To the best of our knowledge, this is the first study to consider the effects of SAI on mesoscale processes using a model like WRF.