On the Bright Side: New Developments in Marine Cloud Brightening Technology

Marine cloud brightening (MCB) is a solar radiation management technique that aims to enhance the albedo and light-scattering properties of marine clouds using seawater. By atomising seawater into highly monodisperse submicron diameter droplets, nanocrystalline salt particles are carried into clouds inducing a ‘brightening’ effect. This could create a local cooling effect and be implemented as a potential intervention for protecting vulnerable systems ranging from the Arctic to the Great Barrier Reef.

 

However, this technique faces significant technical challenges, including the requirement of a narrow droplet size distribution, high production rate, efficiency and a resilience to environmental conditions. To address these challenges, our PhD research draws inspiration from the natural process of sea spray generation by waves on the surface of the ocean. Waves, as they break on the surface of the ocean, entrain air and form bubbles with thin liquid films that burst into thousands of submicron droplets. This process can be emulated through a method known as bubble-bursting atomisation or bubblisation, using only jets of low-pressure air to simultaneously form and burst bubbles of seawater at the gas-liquid interface to generate a fine spray of submicron droplets.

 

In this talk, Yashasvi will present his current progress towards the design, parametrisation, and experimental validation of various bubblisation geometries, as well as the future plans for investigating this method further. The insights gained from this research aim to critically evaluate the viability of bubblisation as a suitable technique for generating droplets for marine cloud brightening.

 

It is becoming evident that regional cooling techniques such as Marine Cloud Brightening will be called upon in the coming decades. After finding only three small groups in the world working on the engineering challenge,  therefore we have set out to develop a spray system for Marine Cloud Brightening. The aim was to develop a sprayer that produces submicron droplets in vast quantities that fall into a controllable, narrow size range. Settling on superheated atomisation as a good potential candidate, we set up a sprayer and particle detection system in a new seawater lab. There are now three of us researching different sprayers in the Seawater lab, operating with an advanced particle detection system which is providing encouraging results. 

 

In this talk, Edmund will be presenting his results from the superheated atomiser along with the technical challenges faced in measuring plumes of sprayed submicron sea water droplets.

 

 

Time: 1pm - 2pm

Location: James Dyson Seminar Room

Address: Department of Engineering, Trumpington Street, Cambridge, CB2 1PZ