Bubble-Bursting Atomisation for Marine Cloud Brightening

Marine cloud brightening (MCB) is a solar radiation management technique aimed at enhancing the albedo or ‘brightness’ of existing marine clouds using only seawater. This could reflect more incoming sunlight to create a local cooling effect and be implemented as a potential intervention for protecting vulnerable systems like the Arctic. Specifically, by spraying seawater into submicron diameter droplets, the resultant dry salt nanocrystals upon evaporation, are delivered into the cloud layer to increase the concentration of cloud condensation nuclei and induce a ‘brightening’ effect. However, generating suitable particles for MCB in real life faces significant technical challenges including a narrow salt particle size distribution, high production rate, efficiency and a resilience to environmental conditions. To address these challenges, My PhD research draws inspiration from the natural process of sea spray generation by waves on the surface of the ocean. Using only jets of low-pressure air, through a method known as bubble-bursting atomisation, bubbles of seawater are simultaneously formed and burst to generate a fine spray of submicron droplets. The insights gained from this research aim to critically evaluate the viability of bubble-bursting atomisation as a suitable method for generating droplets for marine cloud brightening.