Characterization of Aerosols for Stratospheric Solar Radiation Management

Understanding the properties of aerosols under stratospheric conditions is of particular importance for applications in solar radiation management. Aerosols have the potential to influence the Earth's radiative balance by stratospheric aerosol injection (SAI), which increases albedo and enhances the reflection of solar radiation back into space. By investigating the optical properties of various aerosol types under different environmental conditions, we aim to explore materials for SAI that exhibit albedo-enhancing potential while maintaining stability in the stratosphere.

We have developed an optical trapping system with counter-propagating laser beams coupled with cavity-enhanced Raman spectroscopy to monitor the physical properties of single aerosol particles. This technique, supported by bulk measurements, enables us to determine the wavelength-dependent refractive index under different temperature and relative humidity parameters. Our specially designed optical system allows for rapid changes in temperature and relative humidity using a movable platform while maintaining a stable gradient within the cell reproducing stratospheric conditions. Our findings contribute to a deeper understanding of the suitability of aerosols for climate mitigation strategy and the broader effects of their deployment.