Dr Felix Ng
DPhil
School of Geography and Planning
Reader in Theoretical Glaciology


Full contact details
School of Geography and Planning
Geography and Planning Building
Winter Street
Sheffield
S3 7ND
- Profile
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Felix graduated from Engineering Science at the University of Oxford in 1994. Changing field to applied mathematics afterwards, he moved to the Mathematical Institute at Oxford to conduct doctoral research, gaining his DPhil in mathematical glaciology in 1998.
Felix then held a Junior Research Fellowship at St. John's College, University of Oxford from 1998 to 2002. He spent 2001 visiting the University of Washington in Seattle as Royal-Society – Fulbright Research Fellow. There, he developed strong interests in Antarctic glaciology, a subject which he continues to research today.
From 2003 to 2005, Felix was Leavitt Research Fellow in Geosciences at MIT. At one of his projects there, he worked with Maria Zuber to study the polar caps on Mars.
He joined the University of Sheffield in 2005 and is currently Reader in Theoretical Glaciology. In the department/school, he has performed key administrative roles including Exams Officer, Director of Postgraduate Taught Programmes, and Director of Undergraduate Recruitment. He teaches numerous undergraduate/masters modules and has been long-term module convenor of the final-year research dissertations in our undergraduate programmes.
In 2017, Felix visited the University of Otago, New Zealand as William Evans Visiting Fellow to collaborate with glaciologists and ice physicists there.
He was awarded the Leverhulme Trust Research Fellowship in the 2017-18 academic year to conduct research on the tributarisation of ice-stream networks.
Felix won the 2021 Croucher Science Image Awards with a stunning image created from his research findings on Antarctic ice streams (see this newspiece). The Croucher Foundation has since produced an animated version of the image.
Felix is committed to nurturing new generations of glaciologists. During his career, he has trained numerous PhD and MSc graduates, who go on to make important contributions to the field (see lists below).
From 2008–2023, Felix was Programme Director of MSc(Res) Polar and Alpine Change at the university, a role about which he was very passionate and where he imparted a great deal of energy. Under his leadership, the MSc transformed into the leading research masters in glaciology in the country.
From 2010–2015, Felix was invited lecturer on the International Research Summer School on "Glaciers and Ice Sheets in the Climate System" in Karthaus, Italy. Together with Andrew Fowler, he co-edited the “Karthaus Book” – a research-level text covering the lectured subjects at the summer school.
Since 2023 he has been leading the ICERS Research Group (Ice and Climate Researchers at Sheffield) within the School.
He served as a Scientific Editor of Geology in 2005-2007. Since 2015 he has been an Associate Editor of Frontiers in Earth Science: Cryospheric Sciences. He was a panelist on the proposal review panel of the joint US NSF – UK NERC International Thwaites Glacier Collaboration (ITGC) research programme (2018–2026) in West Antarctica. He regularly reviews research papers and grants for journals and funding bodies.
Felix has research collaborators in many countries. Fieldwork and visits with them have taken him to West Antarctica, Iceland, the Tian Shan, the Alps, the Rockies, and Svalbard.
- Research interests
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I am fascinated by how things work in the cryosphere, from the scale of ice crystals to that of glaciers and ice sheets. I am interested in discovering the mechanisms behind observed behaviour. Finding and explaining the unexplained – deriving new insights and interpretations along the way – excites me.
I believe that a proper understanding of glaciological phenomena requires strong foundation from the underlying physics (and chemistry). My work is dedicated to deepening this foundation. My hallmark is the formulation of mathematical theories to explain, quantify and interpret observations. For this, I use the tools of applied mathematics, specifically mathematical modelling – however, note my primary focus on building new models, rather than using models. At the same time, I work very closely with data. Therefore, in much that I do, I collaborate with the observational/field glaciologists and data scientists at the forefront of their subjects. This way I make new friends and learn new subjects from them – traversing the breadth of the discipline – all the time. This is indeed a great part of the fun!
My research interests span these topics:
- Mathematical modelling of interactions between glaciers and ice sheets and the environment
- Ice-core science: post-depositional evolution of climate signals
- Ice-stream dynamics and organisation
- Internal (radar) architecture of the Antarctic Ice Sheet
- Subglacial drainage systems
- Glacier hydrology and dynamics: jökulhlaups & glacier surges
- Glacial geomorphology (landform origin and use in reconstructions)
- Crystal-scale interactions: grain growth & grain-size statistical mechanics
- Mars’s cryosphere: polar caps & mid-latitude glacial deposits and history.
The discoveries in my 2021 paper have propelled me far into ice-core science over the last few years. Multiple lines are being explored with colleagues from the Univ. of Florence, Univ. of Cambridge, and Univ. of Washington to study the alteration of climate signals in ice-core records, which complements ongoing international efforts in retrieving the “oldest ice” from Antarctica (e.g. see BE-OI Project page).
I am interested in supervising PhD students who wish to study the cryosphere by combining mathematical modelling and observational data.
Current PhD student: Ben Cornford (thesis subject: Concentric Crater Fills on Mars); joint supervision with Rob Bryant and Frances Butcher
My past PhD students include Dr. Adam Hepburn (Vice Chancellor Research Fellow, Aberystwyth Univ.), Dr. Jonny Kingslake (Associate Professor, Columbia Univ.), Becky Coles, Dr. Iestyn Barr (Reader, Manchester Metropolitan Univ.).
- Publications
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Edited books
- Glaciers and Ice Sheets in the Climate System. Cham, Switzerland: Springer International Publishing.
Journal articles
- The edges of glaciology. Annals of Glaciology, 66.
- The grain-scale signature of isotopic diffusion in ice. The Cryosphere, 18(10), 4645-4669. View this article in WRRO
- Isotopic diffusion in ice enhanced by vein-water flow. The Cryosphere, 17(7), 3063-3082.
- Multiple sites of recent wet-based glaciation identified from eskers in western Tempe Terra, Mars. Icarus, 386.
- Publisher Correction: Subglacial lakes and their changing role in a warming climate (Nature Reviews Earth & Environment, (2022), 10.1038/s43017-021-00246-9). Nature Reviews Earth and Environment.
- Pervasive diffusion of climate signals recorded in ice-vein ionic impurities. The Cryosphere, 15, 1787-1810. View this article in WRRO
- Morphology and evolution of supraglacial hummocks on debris-covered Himalayan glaciers. EARTH SURFACE PROCESSES AND LANDFORMS, 46(3), 525-539. View this article in WRRO
- Late Amazonian ice survival in Kasei Valles, Mars. Journal of Geophysical Research: Planets, 125(11). View this article in WRRO
- A quasi-annual record of time-transgressive esker formation : implications for ice-sheet reconstruction and subglacial hydrology. The Cryosphere, 14(6), 1989-2004. View this article in WRRO
- Polyphase mid-latitude glaciation on Mars: chronology of the formation of superposed glacier-like forms from crater-count dating. Journal of Geophysical Research: Planets, 125(2). View this article in WRRO
- Creating HiRISE digital elevation models for Mars using the open-source ames stereo pipeline. Geoscientific Instrumentation, Methods and Data Systems, 8(2), 293-313. View this article in WRRO
- An Automated Method for Mapping Geomorphological Expressions of Former Subglacial Meltwater Pathways (Hummock Corridors) From High Resolution Digital Elevation Data. Geomorphology. View this article in WRRO
- Reconstructing ice-flow fields from streamlined subglacial bedforms: A kriging approach. Earth Surface Processes and Landforms, 44(4), 861-876. View this article in WRRO
- Response of surface topography to basal variability along glacial flowlines. Journal of Geophysical Research: Earth Surface, 123(10), 2319-2340. View this article in WRRO
- Differential Geometry of Ice Flow. Frontiers in Earth Science, 6, ---. View this article in WRRO
- Greenland Ice Sheet Surface Topography and Drainage Structure Controlled by the Transfer of Basal Variability. Frontiers in Earth Science, 6, ---. View this article in WRRO
- Ice-Dammed Lake Drainage Evolution at Russell Glacier, West Greenland. Frontiers in Earth Science, 5, 1-16. View this article in WRRO
- Actively evolving subglacial conduits and eskers initiate ice shelf channels at an Antarctic grounding line. Nature Communications, 8(1). View this article in WRRO
- Insights on the formation of longitudinal surface structures on ice sheets from analysis of their spacing, spatial distribution, and relationship to ice thickness and flow. Journal of Geophysical Research: Earth Surface, 122(4), 961-972. View this article in WRRO
- Remote-sensing-based analysis of the 1996 surge of Northern Inylchek Glacier, central Tien Shan, Kyrgyzstan. Geomorphology, 273, 292-307. View this article in WRRO
- Statistical mechanics of normal grain growth in one dimension: A partial integro-differential equation model. Acta Materialia, 120, 453-462. View this article in WRRO
- A new spatially and temporally variable sigma parameter in degree-day melt modelling of the Greenland Ice Sheet 1870–2013. The Cryosphere Discussions, 9(5), 5327-5371.
- Spatial complexity of ice flow across the Antarctic Ice Sheet. Nature Geoscience, 8(11), 847-850. View this article in WRRO
- Modelling channelized surface drainage of supraglacial lakes. Journal of Glaciology, 61(225), 185-199. View this article in WRRO
- A model of crystal-size evolution in polar ice masses. Journal of Glaciology, 60(221), 463-477. View this article in WRRO
- Formation of RADARSAT backscatter feature and undulating firn stratigraphy at an ice-stream margin. Annals of Glaciology, 54(64), 90-96. View this article in WRRO
- Modelling the coupling of flood discharge with glacier flow during jökulhlaups. Annals of Glaciology, 54(63), 25-31. View this article in WRRO
- Quantifying the predictability of the timing of jökulhlaups from Merzbacher Lake, Kyrgyzstan. Journal of Glaciology, 59(217), 805-818. View this article in WRRO
- An extended "perfect-plasticity" method for estimating ice thickness along the flow line of mountain glaciers. Journal of Geophysical Research: Earth Surface, 117(1).
- Kinematic waves in polar-firn stratigraphy. Journal of Glaciology, 57(206), 1119-1134. View this article in WRRO
- Ice-marginal sediment delivery to the surface of a high-Arctic glacier: Austre Brøggerbreen, Svalbard. Geografiska Annaler. Series A. Physical Geography, 92(4), 437-449.
- Ice-marginal sediment delivery to the surface of a high-arctic glacier: Austre brøggerbreen, svalbard. Geografiska Annaler, Series A: Physical Geography, 92(4), 437-449.
- Using the surface profiles of modern ice masses to inform palaeo-glacier reconstructions. Quaternary Science Reviews, 29(23-24), 3240-3255. View this article in WRRO
- Size and shape characteristics of drumlins, derived from a large sample, and associated scaling laws. QUATERNARY SCI REV, 28(7-8), 677-692.
- Temporal dynamics of a jökulhlaup system. Journal of Glaciology, 55(192), 1-15. View this article in WRRO
- A glacier respires: Quantifying the distribution and respiration CO2 flux of cryoconite across an entire Arctic supraglacial ecosystem. J GEOPHYS RES-BIOGEO, 112(G4). View this article in WRRO
- Climatic control on the peak discharge of glacier outburst floods. Geophysical Research Letters, 34(21). View this article in WRRO
- Mount Everest, The Reconnaissance 1935: 'The Forgotten Adventure' - by Tony Astill. The Geographical Journal, 172(4), 351-351.
- Patterning instability on the Mars polar ice caps. Journal of Geophysical Research E: Planets, 111(2). View this article in WRRO
- Fast-growing till over ancient ice in Beacon Valley, Antarctica. Geology, 33(2), 121-121. View this article in WRRO
- Fast-flow signature in the stagnated Kamb Ice Stream, West Antarctica. Geology, 32(6), 481-481. View this article in WRRO
- On the Clague-Mathews relation for jökulhlaups. Journal of Glaciology, 49(165), 161-172.
- Thermally controlled glacier surging. Journal of Glaciology, 47(159), 527-538.
- Coupled ice–till deformation near subglacial channels and cavities. Journal of Glaciology, 46(155), 580-598.
- A. Post and E. R. Lachapelle. 1999. Glacier ice. Revised edition.
Seattle, WA, University of Washington Press, in association with International Glaciological Society, Cambridge, England. 144 pp. ISBN 0-295-97910-0, paperback. $27.95.. Journal of Glaciology, 46(155), 700-700.
- Canals under sediment-based ice sheets. Annals of Glaciology, 30, 146-152.
- The role of sediment transport in the mechanics of jökulhlaups. Annals of Glaciology, 22, 255-259.
- Global synthesis of subglacial lakes and their changing role in a warming climate.
- Exploring the causes of glacier velocity anomalies in High Mountain Asia: Analysis from the Karakoram, Spiti Lahaul and Eastern Himalaya.
- Subglacial lakes and their changing role in a warming climate. Nature Reviews Earth & Environment. View this article in WRRO
Chapters
- Sliding, Drainage and Subglacial Geomorphology, Springer Textbooks in Earth Sciences, Geography and Environment (pp. 47-78). Springer International Publishing
- A Mathematical Model of Wide Subglacial Water Drainage channels, Ice Physics and the Natural Environment (pp. 325-327). Springer Berlin Heidelberg
Conference proceedings papers
- View this article in WRRO
- MELTWATER LANDFORM PERSPECTIVES ON SUBGLACIAL HYDROLOGICAL PROCESSES: INSIGHTS FROM HIGH-RESOLUTION MAPPING IN NORTHERN CANADA. Geological Society of America Abstracts with Programs
- Ice-mass survival for approximately 800 Myr in the tropical Kasei Valles region, Mars. Sharing Geoscience Online View this article in WRRO
Software / Code
Datasets
- Computer code and simulated data of the paper "Pervasive diffusion of climate signals recorded in ice-vein ionic impurities".
- Supplement of the paper "Pervasive diffusion of climate signals recorded in ice-vein ionic impurities".
- Planimetric ice-flow convergence and flow-orthonormal strain rate across the Antarctic Ice Sheet.
- Mapping of meltwater features and De Geer moraines in central Nunavut, Canada from the high-resolution (2 m) ArcticDEM.
- Supplementary material to "Pervasive diffusion of climate signals recorded in ice-vein ionic impurities".
Other
- Supplementary material to "Doomed descent? How fast sulphate signals diffuse in the EPICA Dome C ice column".
- Supplementary material to "The grain-scale signature of isotopic diffusion in ice".
- Towards a theory for the formation of sea stacks.
- Diffusive smoothing of isotopic signals in ice cores: the grain-scale signature of excess diffusion as a testable prediction.
- Supplementary material to "Isotopic diffusion in ice enhanced by vein-water flow".
Preprints
- Doomed descent? How fast sulphate signals diffuse in the EPICA Dome C ice column, Copernicus GmbH.
- Review Article: Antarctica’s internal architecture: Towards a radiostratigraphically-informed age–depth model of the Antarctic ice sheets, Copernicus GmbH.
- The grain-scale signature of isotopic diffusion in ice, https://egusphere.copernicus.org/preprints/2024/egusphere-2024-1012/.
- Glaciers and Ice Sheets in the Climate System. Cham, Switzerland: Springer International Publishing.
- Teaching activities
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My teaching encompasses the theoretical, empirical and skill elements of geoscience. Breaking down complex things and explaining them simply is challenging, and this is what I try to do with my students.
I am fortunate to have been taught by people who are truly inspirational; I try to follow in their footsteps by launching students into the fun of thinking and problem-solving. I do this by a range of methods to get my students to push ideas in words and drawings with me. To me, a key ingredient of effective teaching is the art of getting across the essential story of the science, whether when unpicking individual papers or the complex web of interacting research studies.
I teach numerous undergraduate and postgraduate modules: Unlocking Past Environmental Changes (Level 2; and as module convenor); Glacial Processes (Level 2); The Planets (Level 3; convenor), Geoscientific Data Analysis using MATLAB (Level 3; convenor); Current Issues in Polar and Alpine Research (MScRes; convenor); and Polar and Alpine Change Research Project (MScRes; past convenor, 2009-2023).
I also lead the Level-2 Research Design/Proposal module and the Level-3 (final year) Undergraduate Research Dissertation – as the convenor for physical geography and environmental science students, working alongside a human-geography convenor.
From 2008 to 2023, I was Programme Director of MSc(Res) Polar and Alpine Change at the University of Sheffield. I am proud to say that this research masters has educated more than 150 graduates over the years – some 80 of them successfully securing PhD places afterwards to tackle different areas of glaciological, polar and climate science. Many of them are now established scientists.
For my undergraduate teaching contributions, I won a University Senate Award for Excellence in Learning and Teaching in 2010. For my sustained efforts over a decade as Director of the MSc(Res) Polar and Alpine Change programme, I was nominated by my department for the University of Sheffield 2023 Education Award (‘Leadership category’).
My former MSc/undergraduate research students include: Anwesha Sharma (Durham Univ., PhD student), Dr. Joanna Zanker (Research Fellow, Northumbria Univ.), Dr. Vicky Dutch (Research Associate, UEA), Dr. Adam Hepburn (Research Fellow, Aberystwyth Univ.), Dr. Olly Bartlett (Senior Lecturer, Univ. Hertfordshire), Clement Hutin (Operational Meteorologist, UK Met Office), Dr. Pierre-Marie Lefeuvre (Oslo Univ.), Dr. Damien Mansell (Associate Prof., Exeter Univ.).
- Additional research projects
Ice Dynamics
I had earlier investigated the surge behaviour of sub-polar glaciers with Tavi Murray (Leeds) and Andrew Fowler (Oxford) and recently turned my attention to the Antarctic ice streams, whose variable flow exerts strong control on ice-sheet mass balance.
With Howard Conway (Seattle), I used the radar structures in Kamb Ice Stream to infer its flow speed before it stopped ~150 years ago. Ongoing work considers the general problem of deciphering the history of ice flow from englacial radar layers.Radar X-section of Kamb Ice Stream, showing undulating layers in ice ~1800 m deep (horizontal axis in km)
Model of isochrone-layer deformation along a flow band in an ice stream
Glacier Hydrology
Catastrophic outburst floods from ice-dammed lakes, known as jökulhlaups, can deliver several cubic kilometres of water suddenly with a peak discharge ranging up to 105 m3 s-1, causing severe environmental and economic impact.
In order to identify factors that regulate their timing and magnitude, I am studying the mechanics of these floods worldwide and also locally, using examples from Iceland and from the Tian Shan.
Fieldwork on the moraine-dammed lake at Grinnell Glacier, Rocky Mountains
Glacial Geomorphology
Glaciation leaves behind a variety of bedforms on the Earth surface. Part of my research explores how they form, with an aim to reconstruct the conditions of past ice flow using them and to learn something about the processes that operate at the glacier bed.
The following images show two examples which I have studied.
Centimetre-scale: Pins of calcite precipitate protruding from the leeside of a limestone bed specimen (collected by Bernard Hallet from Castleguard Glacier, Canada)
Kilometre-scale: Drumlins of the Puget Sound, Washington State, USA. This LIDAR image is about 6 km wide. Image courtesy: Ralph Haugerud.
When sediment-laden ice sublimates, a debris layer (an ablation till) forms on the surface and it can become thick enough to obscure the ice.
This situation is found in central Beacon Valley, Antarctica. Together with collaborators at the University of Washington, I have studied the cosmogenic.
He systematics of the debris accretion process and applied our model to understand how the till layer in Beacon Valley developed while it also became spectacularly patterned by contraction-crack polygons
Beacon Valley (photo by Ron Sletten)
Polygonal pattern on the sublimation till that covers relict ice (not visible) in Beacon Valley. The polygon diameter is about 10m.