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TU Delft visit Cambridge for MCB discussions
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The Centre for Climate Repair was joined by friends and colleagues from TU Delft this week. Over two days, students and researchers presented their latest work on Marine Cloud Brightening (MCB) ideas. The Cambridge side are developing the technology to spray seawater crystals into the atmosphere to form brighter clouds, while TU Delft are modelling the potential effects and requirements. Together, they hope to develop a suite of knowledge on this potential solution to protect the Arctic.
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Marine Cloud Brightening (MCB) is a solar radiation management strategy aimed at increasing the amount of incoming solar radiation which is reflected back into space from clouds over the oceans. Increasing cloud albedo is achieved by increasing the number of cloud condensation nuclei (CCN) present within the clouds which leads to smaller cloud droplets and a whiter, brighter, appearance - a phenomenon known as the Twomey effect. MCB involves spraying small seawater droplets into the atmosphere which then evaporate, and the resulting salt crystals act as new CCNs when they reach the cloud boundary layer.
Much of the work at CCR is aimed at developing efficient spraying techniques that can generate large quantities of submicron seawater droplets for the purpose of MCB. The CCR is researching the performance and suitability of a variety of spraying methods including:
- Superheated atomisation involves spraying seawater at very high temperatures and pressures, through a nozzle of precise geometry, to achieve a fine mist of droplets. Researcher Edmund Reardon is the lead on this method.
- Electrospraying involves the application of high voltage to a liquid, as opposed to high pressure, to emit submicron jets from narrow capillaries which disintegrate into streams of droplets. Researcher Jake Chapman is the lead on this method.
- Rayleigh jet disintegration from micron and sub-micron sized holes in silicon, for the purpose of MCB, is being investigated by researcher Jake Chapman, with assistance and technology from Medspray B.V.
- Bubble-bursting atomisation is inspired by natural sea spray and uses low-pressure air jets to simultaneously form and burst seawater bubbles. Researcher Yashasvi Raj is the lead on this method.
Two undergraduate students are also investigating other factors for this nozzle development. Orla Hill is testing filtration methods, while Elisabeth Franks is researching the impacts of flow pulsation.
The MCB research is led by Professor Hugh Hunt in the Department of Engineering.
Professor Herman Russchenburg leads the team at TU Delft, who are working on the modelling and cloud physics necessary to develop and test the idea.
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We also enjoyed a tour of the lab and some classic Cambridge spots! Supported by Refreeze the Arctic Foundation, the two universities have been collaborating and meeting for over two years; we are excited to continue working together for the sake of the Arctic and the planet.
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