Professor Daniel Feltham

Biography

Daniel Feltham (Danny) earned a BSc. in Physics from Durham University in 1993. He worked for the UK Ministry of Defence as an operational analyst, before winning a scholarship in 1995 to study for a Ph.D. in Applied Mathematics at Cambridge University, awarded in 1998. His PhD was on the fluid dynamics and thermodynamics of sea ice and involved mushy layer theory, perturbation methods and stability analyses. After two short postdocs in mathematical biology and crystallization of emulsions, Danny joined University College London as an Academic Fellow in Climate Physics in 1999, being promoted to Lecturer in 2002, and to Reader in Polar Oceanography in 2005. Danny joined the University of Reading as Professor in Climate Process Physics in 2012. Danny is a mathematical physicist with interests and expertise in the fundamental study of physical processes in the cryosphere using continuum mechanics and thermodynamics, devising new mathematical models of these processes, using these models to generate new understanding, and developing parameterisations suitable for implementation into climate models. Scalability, homogenisation, isotropy, and continuity are frequently occurring issues. This work combines the development of new theory with numerical simulations and laboratory experiments, and utilises field measurements and remotely-sensed observations. Research Group in Sea ice and Polar Oceanography Danny leads a research group in polar oceanography, with a strong focus on sea ice. Sea ice is an important component of the global climate, e.g. it strongly impacts atmosphere-ocean heat fluxes, greatly increases the Earth’s albedo and contributes to thermohaline forcing of the ocean. Sea ice is also a sensitive indicator of climate change: there have been well-publicised, strong reductions in Arctic summer sea ice extent in the last decade. Existing regional and climate models do a rather poor job of simulating the evolution of sea ice, underestimating the decrease in the Arctic and predicting a strong decrease in the Southern Ocean where there is actually a small increase. While the causes of poor climate sea ice simulations can be obscure, the thrust of much of Danny’s research is to improve the fidelity of physical models of sea ice in regional and climate models. It can be shown that uncertainty in the sea ice physics alone can be responsible for poor sea ice simulations. Reduction in the sea ice cover has implications for climate, trade, wildlife, society, and oil exploration. Measuring, understanding, and predicting changes in sea ice and the polar oceans requires a broad range of expertise and is essentially interdisciplinary. Much of Danny’s research, although quite specialised, is collaborative and contributes to broader-themed research projects. Danny’s group comprises a number of postdoctoral fellows and PhD students (with strong backgrounds in mathematics and physics) and most of its research falls into the following areas: Sea ice thermodynamics - including mushy layer theory, ice-ocean interface dynamics, consolidation of rafted ice, freezing and melting/dissolving, melt pond formation and spreading and impact on albedo and Arctic mass balance; Sea ice dynamics and rheology - including topographic form drag, edge jets and kinetic granular flows in the Marginal Ice Zone, anisotropic sea ice rheology and its representation in climate models using structure tensors, discrete element modelling of floe aggregate formation, and experimental determination of the relationship between sea ice rheology and friction (a little dated now, but for a review of some of these topics see Danny’s 2008 Ann. Rev. Fluid. Mech. review paper); Interaction of ice with the polar ocean - including frazil ice formation and mixed layer properties, mixed layer evolution in Antarctic continental shelves, salinity-driven deep water formation, ice shelf-ocean interaction and marine ice deposition, numerical simulation of density-driven flows; and Incorporation of new physics into sea ice climate models - maintaining a CPOM version of the Los Alamos CICE sea ice climate model component allows Danny's group to make Arctic climate predictions and provides a route for "pull through" from fundamental process studies to climate models.

Research Interest

Exploring the role of sea ice physics in Arctic climate variability and predictability Anisotropic sea ice mechanics in the Arctic Atmosphere to ocean momentum transfer by sea ice Centre for Polar Observation and Modelling: NERC National Capability in climate sea ice model development and sea ice modelling in the Arctic