Ice nucleation: vital to our climate


Contact Dr. Hugo Christenson to discuss this project further informally

Project description

Ice formation by nucleation in the upper atmosphere is a critical factor in the energy balance of the earth and in climate change.  The number and size of ice crystals in cirrus clouds determine their reflectivity and absorption of radiation, and thereby the net heating effect of the sun. Ice in the lower atmosphere typically forms by the freezing of liquid water or solution droplets, which is the origin of precipitation. By contrast, ice formation in the upper atmosphere occurs by deposition from water vapour on micron-size aerosol particles of terrestrial origin, carried aloft by winds.  These are usually aluminosilicate minerals like clays or feldspars, which differ both in the chemical and physical nature of their surfaces. The particles are often far from smooth with a profusion of topographical features like pits and grooves.  The relative importance of surface chemistry and topography is currently a hotly debated topic, both from a fundamental perspective and with regard to predicting the ice-nucleating efficiency of different surfaces.  This is of great significance, not only in the atmospheric sciences, but also for medical and biological processes like cryopreservation of physiological samples as well as for the frozen food industry.

In this project you will study ice nucleation on surfaces, in particular minerals such as feldspar, quartz and mica, in order to increase our understanding of the relative importance of the chemical composition of the surface and its topography. You will use both naturally occurring mineral samples and surfaces with intentionally introduced topographical features, to study nucleation and crystal growth from water vapour and from liquid water. 

You will be part of a large group involving researchers in Physics, Chemistry and Earth and Environment. The project will give ample opportunity for inter-disciplinary collaboration and to become familiar with techniques like optical microscopy, scanning and transmission electron microscopy, atomic force microscopy (AFM), Raman spectroscopy, X-ray diffraction and various surface-modification techniques. Because crystallisation is of great importance across many areas of science, medicine and technology your future career prospects will be excellent. 

Entry requirements

Applications are invited from candidates with, or expecting, a minimum of a UK upper second class honours degree (2:1) in a relevant discipline, a Master's degree in a relevant discipline, or both.

How to apply

Formal applications for research degree study should be made online through the university's website. Please state clearly in the research information section that the PhD you wish to be considered for is 'Ice nucleation – vital to our climate ' as well as Dr. Hugo Christenson as your proposed supervisor.

If English is not your first language, you must provide evidence that you meet the University’s minimum English Language requirements.

If you require any further information please contact the Graduate School Office

We welcome scholarship applications from all suitably-qualified candidates, but UK black and minority ethnic (BME) researchers are currently under-represented in our Postgraduate Research community, and we would therefore particularly encourage applications from UK BME candidates.  All scholarships will be awarded on the basis of merit.