Exploring Future Northern Hemisphere Winter Seasonal Variability and Predictability under Stratospheric Aerosol Injection

To help reduce climate change impacts, various forms of solar radiation modification have been proposed to cool the planet. One method to intentionally reflect sunlight into space is through the introduction of reflective particles into the stratosphere, known as stratospheric aerosol injection (SAI). Previous research has shown that SAI implementation could lead to future climate impacts beyond surface temperature, including a reduction in future tropical precipitation compared to a future climate without SAI. This response has the potential to modulate midlatitude variability through tropical precipitation's ability to influence global circulation. Here, we explore possible differences in future boreal winter surface temperature variability and predictability under SAI compared to a climate scenario (SSP2-4.5) without SAI, using the ARISE-SAI simulations. We find significantly higher surface temperature variability over North America and more consistent La Niña teleconnections to the northwest coast of North America under SAI compared to SSP2-4.5. Additionally, we demonstrate that the northwest coast is also associated with higher seasonal predictability of surface temperature under SAI. These results demonstrate that in the ARISE-SAI simulations, SAI can lead to higher seasonal variability and predictability along the northwest coast of North America compared to a future climate without SAI.