Developing a next generation representation of the ocean for atmospheric chemistry transport models

Computer models of the Earth system are a central tool in understanding how atmospheric processes and feedbacks impact global climate and air quality, two pressing social issues. These models need to provide sufficient detail to be able to simulate key interactions, such as that between the atmosphere and the biosphere. The vast majority of the Earth is covered by ocean and so air-sea interactions are critical. Historically, the process level representation of this interaction has been somewhat simplistic. However, over the last decade, as observations have increased, our understanding of processes occurring between the ocean and the atmosphere has improved (see for example [Ganzeveld et al., 2009; Bell et al., 2013; Carpenter et al., 2013]) to the point where a more detailed numerical description of the processes occurring at the ocean-atmosphere interface is now warranted.

The focus of this project will be on developing a new ocean-atmosphere module representing the physics, chemistry, and biology of the ocean, together with the exchange between the top of the ocean and the bottom of the atmosphere. The initial activity will be on developing the ocean tracer transport module based on the assimilated products being produced by the Copernicus Marine project (http://marine.copernicus.eu). This model will be tested against CFC observations and models contributing the OMIP modelling effort [Griffies et al., 2016] to allow its veracity to be assessed. Subsequently the representation of the photolytic breakdown of compounds in the ocean will need to be included. Once these processes are in place the chemistry and biology of the oceans can be considered. Long lived chemical (Cl-, NO3- etc.) and biological components (chlorophyll, dissolved organic carbon etc.) will be driven by the Copernicus products. The initial chemical development will be on the ocean production, loss and emission of methyl iodide into the ocean as it is thought to be represented by a relatively simple chemistry / biological system. The ultimate goal is to understand the exchange between the atmosphere and the atmosphere of reactive compounds in general and to specifically include a much better representation of the ocean deposition of ozone and its subsequent surface chemistry. The atmospheric component of the modelling will use the GEOS-Chem model (www.geos-chem.org), an open source community atmospheric chemistry transport model. Prof Evans has extensive experience of using this model. The project will exploit computing resources available to the atmospheric chemistry group at the University of York. Ongoing ocean-atmospheric and ocean chemistry research from Prof Carpenter’s field and laboratory studies will be incorporated into the project analysis.

Related undergraduate subjects: Maths, Physics, Engineering, Chemistry, Numerical Modelling

Shortlisting will take place as soon as possible after the closing date and successful applicants will be notified promptly. Shortlisted applicants will be invited to a panel interview to take place at the University of Leeds in the week commencing 13 February 2017.

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