Atmosphere/sea ice interactions: using Artificial Intelligence (AI) and satellite data to map turbulent exchange properties from space

Turbulent exchange between sea ice and the atmosphere is a key component of the surface energy budget in polar regions, but poorly represented in climate and weather forecast models. This project brings together recent advances in satellite retrievals of sea-ice surface properties and the parameterization of turbulent exchange to develop remote sensing products from which maps of turbulent exchange coefficients can be derived for direct use in weather forecast models.

Sea ice covered ocean is usually a mixture of ice floes and open leads, exposing water surface, and in the summer extensive regions of surface melt, forming ponds and ultimately melting right through the ice. Surface-atmosphere turbulent exchange coefficients over fractional sea ice are usually specified as a weighted sum of those for ice and open water. Recently the additional drag from the edges of leads has been included, resulting in a peak in drag at ice fractions of about 60%-80%. Still missing is any measure of the inherent roughness of the ice surface, resulting from ridges and rafting of ice floes. The representation of ice fraction is also simplistic, taking no account of the respective scales of ice floes and leads.

This project will combine data from multiple sources to develop unique, state-of-the-art representations of surface exchange over sea ice. In situ turbulent flux measurements made from both ships and aircraft, from multiple field campaigns, including the year-long MOSAiC project,

will be combined with data from satellite radar altimetry that provides various measures of surface roughness to derive estimates of the drag coefficient directly from the satellite data. A unique feature of this work will be the extension of newly developed artificial intelligence, or machine learning algorithms to classify the ice surface into floes and leads, in order to determine the characteristic scales of each. These will be used for the first time to drive state-of-the-art parameterizations of surface exchange coefficients; they also provide a unique source of validation for models of sea ice. The most advanced sea ice models represent these quantities and use them to specify the drag coefficient within climate models, but have not been validated against direct measurements because of a lack of suitable data.

This interdisciplinary project offers an opportunity to work at the intersection of climate and space science, and contribute to several international research collaborations. You will work with world-leading experts in polar climate, atmospheric boundary layer processes, satellite measurements, and advanced computational techniques. Dr Anna Hogg will supervise the use of synthetic aperture radar (SAR) measurements from multiple satellites (e.g. CryoSat-2, ERS-1/2, Sentinel-1) to characterise the surface properties of sea ice using AI techniques developed to track features of the Antarctic and Greenland ice sheets. Prof Brooks will supervise the use of the satellite derived surface properties along with in situ measurements of surface turbulent fluxes, to develop new parameterizations of turbulent exchange based on the satellite measurements.

During your PhD you will lead at least three research articles in leading scientific journals. You will have the valuable opportunity to work with researchers at many international institutes, including the European and German Space Agencies (ESA & DLR), and partners on the projects from which in situ data is drawn, including the University of Stockholm, University of East Anglia, and University of Colorado, Boulder.

The successful applicant will have access to a broad spectrum of specialist training in Earth Observation, meteorology, and climate science, in addition to the extensive University of Leeds workshops on a range of topics, including scientific programming through to managing your degree. Applicants will hold good first degree (first or high 2.1) or Master’s degree in physics, maths, Earth science, climate science, computer science, Earth observation or a related discipline. We welcome applications from a wide range of backgrounds, including those with non-traditional qualifications or from industry – please contact us to have a chat about your suitability for the programme.

To apply for this position please provide a copy of your CV, a two page personal statement, degree transcripts and references. An  On-Line Study Application (OLA)should be submitted to Leeds via  University Application for Research Degree Study.