Quantifying and understanding dimethylsulfide variability and its influence on the climate system

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The Met Office and NERC are jointly developing the UK's next generation Earth System Model. This model has a large Southern Ocean temperature bias arising in part from clouds allowing too much sunlight to reach the ocean's surface. This temperature bias compromises the reliability of future climate projections. Cloud droplets form on particles in the atmosphere. These particles come from a mixture of natural and human sources. More cloud droplets mean brighter (more reflective) clouds, and less sunlight passing through those clouds. Present-day cloud brightness reflects the natural 'background' particle production, and the number of human-produced (anthropogenic) particles that are transported over the Southern Ocean. This natural/anthropogenic particle ratio is critical to understand how the system will respond to increases/decreases in anthropogenic particle emissions, because changes on top of a 'clean' atmosphere have a much bigger impact than changes in an already 'dirty' atmosphere. This studentship aims to (1) determine the level and range of possible background emissions of the primary biological particle source in the region, dimethylsulphide, (2) implement changes to these emissions in the Met Office model, and (3) explore the implications of this for the model's Southern Ocean, and climate change.