William Colgan, Ph.D.

I am an assistant professor in the Department of Earth and Space Science and Engineering at York University in Toronto, Canada. I am also an adjunct research associate at the Cooperative Institute for Research in Environmental Sciences (CIRES) in Boulder, Colorado. I am currently serving on the International Glaciological Society (IGS) executive council and publications committee, as well as the Canadian Cryospheric Information Network (CCIN) advisory council. I completed my Ph.D. in Geography at the University of Colorado.

  • mail:  York University, 4700 Keele Street, Toronto, M3J 1P3, Canada
  • office:  PSB 110
  • phone:  +1 416 736 2100 x 77703
  • Skype:  liamcolgan
  • email:  info@williamcolgan.net


I blog about glaciers on Glacier Bytes


I study the interactions between climate and glaciers. Although people tend to think of glaciers as solid objects, they actually behave as a fluid, flowing on geological timescales like an extremely viscous river. My primary research interest is understanding the consequences of climate change on the Greenland Ice Sheet. I study the Greenland Ice Sheet using a combination of computer modeling, satellite remote sensing and field observations. Many of these data products are updated daily at PolarPortal.org, a site dedicated to monitoring real-time changes in Arctic ice.

The computer models that I use incorporate many of the physical processes that influence ice flow as possible, from the slow viscous flow driven by gravity, to the effect of ice temperature on ice viscosity. Given the vastness and inaccessibility of polar areas, remotely sensed satellite observations provide very important computer model input. I participate on polar expeditions to collect field data that is used to calibrate and validate both the computers models and satellite observations.

I think the video below does a great job breaking down how glacier modellers work to understand past and future changes in glacier form and flow. The video is part of the open source exhibition Mathematics of Planet Earth, hosted by imaginary.org.

Field Expeditions

I have had the opportunity to participate on over 300 days of expeditions to the Canadian Arctic, Greenland and Antarctica. The highs and lows of the most recent expedition in which I participated, Arctic Circle Traverse 2013, are recorded in the ACT-13 blog. While field work is undertaken to collect data, I believe it serves an equally important purpose in fostering a holistic view of Earth surface processes. I have posted some of my favourite photos from my time in the field in my Picasa Web Album.

Videos can nicely capture field work and life. Dan McGrath (co-author) has put together a mash-up of one of our Greenland seasons (left): it's a testament to Apple's iMovie software!

Communicating Science

I value communicating my research findings beyond peer-reviewed publications and the scientific community. The press releases below provide good overviews of the research questions in which I am interested and have given me the opportunity to participate in media outreach.

Like butter: Study explains surprising acceleration of Greenland’s inland ice. (18 July 2013 - NASA)

Northern hemisphere losing last dry snow region, says CU study. (20 May 2013 - University of Colorado at Boulder)

Alaska’s iconic Columbia Glacier expected to stop retreating in 2020, says CU-Boulder study. (26 November 2012 - University of Colorado at Boulder)

New CU-Boulder study indicates Greenland may be slip sliding away due to surface lake melt. (16 April 2012 - University of Colorado at Boulder)

Increased crevasse extent in Greenland may dampen ice sheet sliding. (19 September 2011 - Cooperative Institute for Research in Environmental Sciences)

I enjoy speaking to students and teachers about various aspects of cryospheric research and climate change. My prepared high school talks include: (1) an overview of the most recent UN IPCC Report, and (2) an overview of the recovery and utility of ice cores. My prepared middle school talks include: (1) the use of satellites in studying the cryosphere, and (2) living and working on an ice sheet. Below James Balog (co-author) talks about monitoring glaciers with time-lapse photography as part of the Extreme Ice Survey.


I publish peer-reviewed papers in a variety of journals that have a focus on glacier-climate interactions. I am happy to see many journals moving towards an "open" format, whereby articles are available for free. I have provided .pdf links below, in case you have trouble accessing any of the "closed" links. My GoogleScholar profile tracks where my research is being cited.

26. W. Colgan, A. Sommers, H. Rajaram, W. Abdalati and J. Frahm. 2015. Considering thermal-viscous collapse of the Greenland ice sheet. Earth's Future. 3: 1-16. doi:10.1002/2015EF000301. [web] [.pdf]

25. W. Colgan, W. Abdalati, M. Citterio, B. Csatho, X. Fettweis, S. Luthcke, G. moholdt, S. Simonsen and M. Stober. 2015. Hybrid glacier Inventory, Gravimetry and Altimetry (HIGA) mass balance product for Greenland and the Canadian Arctica. Remote Sensing of Environment. 168: 24-39. doi:10.1016/j.rse.2015.06.016. [web] [.pdf]

24. W. Colgan, J. Box, M. Andersen, X. Fettweis, B. Csatho, R. Fausto, D. van As and J. Wahr. 2015. Greenland high-elevation mass balance: inference and implication of reference period (1961-90) imbalance. Annals of Glaciology. 56: 105-117. doi:10.3189/2015AoG70A967. [web] [.pdf]

23. M. Andersen, L. Stenseng, H. Skourup, W. Colgan, S. Khan, S. Kristensen, S. Andersen, J. Box, A. Ahlstrøm, X, Fettweis and R. Forsberg. 2015. Basin-scale partitioning of Greenland ice sheet mass balance components (2007–2011). Earth and Planetary Science Letters. 409: 89-95. doi:10.1016/j.epsl.2014.10.015. [web] [.pdf]

22. W. Colgan. 2014. Considering the ice excavation required to establish and maintain an open ice pit. Journal of Cold Regions Engineering. 28: 04014003. doi:10.1061/(ASCE)CR.1943-5495.0000067. [web] [.pdf]

21. D. Van As, R. Fausto, K. Steffen and The PROMICE Team. 2014. Katabatic winds and piteraq storms: observations from the Greenland ice sheet. Geological Survey of Denmark and Greenland Bulletin. 31: 83-86. [web] [.pdf]

20. M. Andersen, S. Andersen, L. Stenseng, H. Skourup, W. Colgan, S. Kristensen, J. Merryman-Boncori, A. Ahlstrøm, X. Fettweis, R. Forsberg, M. Citterio, J. Box, D. van As and R. Fausto. 2014. Mass loss from an ice-sheet drainage basin in West Greenland. Geological Survey of Denmark and Greenland Bulletin. 31: 87-90. [web] [.pdf]

19. W. Colgan, J. Box, R. Fausto, D. van As, V. Barletta and R. Forsberg. 2014. Surface albedo as a proxy for the mass balance of Greenland's terrestrial ice. Geological Survey of Denmark and Greenland Bulletin. 31: 91-94. [web] [.pdf]

18. W. Colgan, S. Luthcke, W. Abdalati and M. Citterio. 2013. Constraining GRACE-derived cryosphere-attributed signal to irregularly shaped ice-covered areas. The Cryosphere. 7: 1901-1914. doi:10.5194/tc-7-1901-2013. [web] [.pdf]

17. W. Colgan and L. Arenson. 2013. Open pit glacier ice excavation: A brief review. Journal of Cold Regions Engineering. 27: 223-243. doi:10.1061/(ASCE)CR.1943-5495.0000057 [web] [.pdf]

16. J. Box and W. Colgan. 2013. Greenland ice sheet mass balance reconstruction. Part III: Marine ice loss and total mass balance (1840-2010). Journal of Climate. 26: 6990-7002. doi:10.1175/JCLI-D-12-00546.1. [web] [.pdf]

15. T. Phillips, H. Rajaram, W. Colgan, K. Steffen and W. Abdalati. 2013. Evaluation of cryo-hydrologic warming as an explanation for increased ice velocities in the wet snow zone, Sermeq Avannarleq, West Greenland. Journal of Geophysical Research. 118. doi:10.1002/jgrf.20079. [web] [.pdf]

14. D. Van As, R. Fausto, W. Colgan, J. Box and The PROMICE Team. 2013. Darkening of the Greenland ice sheet due to the melt-albedo feedback observed at PROMICE weather stations. Geological Survey of Denmark and Greenland Bulletin. 28: 69-72. [web] [.pdf]

13. D. McGrath, W. Colgan, N. Bayou, A. Muto and K. Steffen. 2013. Recent warming at Summit, Greenland: Global Context and Implications. Geophysical Research Letters. 40. doi:10.1002/grl.50456. [web] [.pdf]

12. T. Zhang, C. Xiao, W. Colgan, X. Qin, W. Du, X. Liu, W. Sun, Y. Liu and M. Ding. 2013. Observed and modelled ice temperature and velocity along the main flowline of the East Rongbuk Glacier, Mt. Qomolangma (Everest). Journal of Glaciology. 59: 438-448. doi:10.3189/2013JoG12J202. [web] [.pdf]

11. W. Colgan, W. Pfeffer, H. Rajaram, W. Abdalati and J. Balog. 2012. Monte Carlo ice flow modeling projects a new stable configuration for Columbia Glacier, Alaska, c. 2020. The Cryosphere. 6: 1395-1409. doi:10.5194/tc-6-1395-2012. [web] [.pdf]

10. R. Anderson, M. Dühnforth, W. Colgan and L. Anderson. 2012. Far-flung moraines: Exploring the feedback of glacial erosion on the evolution of glacier length. Geomorphology. 179: 269-285. doi:10.1016/j.geomorph.2012.08.018. [web] [.pdf]

9. Y. Liang, W. Colgan, Q. Lv, K. Steffen, W. Abdalati, J. Stroeve, D. Gallaher and N. Bayou. 2012. A decadal investigation of supraglacial lakes in West Greenland using a fully automatic detection and tracking algorithm. Remote Sensing of Environment. 123: 127-138. doi:10.1016/j.rse.2012.03.020. [web] [.pdf]

8. W. Colgan, H. Rajaram, R. S. Anderson, K. Steffen, H. Zwally, T. Phillips and W. Abdalati. 2012. The annual glaciohydrology cycle in the ablation zone of the Greenland Ice Sheet: Part 2. Observed and modeled ice flow. Journal of Glaciology. 58: 51-64. doi:10.3189/2012JoG11J081. [web] [.pdf]

7. W. Colgan, K. Steffen, W. S. McLamb, W. Abdalati, H. Rajaram, R. Motyka, T. Phillips, and R. Anderson. 2011. An increase in crevasse extent, West Greenland: Hydrologic implications. Geophysical Research Letters. 38. L18502. doi:10.1029/2011GL048491. [web] [.pdf]

6. D. McGrath, W. Colgan, K. Steffen, P. Lauffenburger and J. Balog. 2011. Assessing the summer water budget of a moulin basin in the Sermeq Avannarleq ablation region, Greenland Ice Sheet. Journal of Glaciology. 57: 954-964. doi:10.3189/002214311798043735. [web] [.pdf]

5. W. Colgan, H. Rajaram, R. Anderson, K. Steffen, T. Phillips, I. Joughin, H. Zwally and W. Abdalati. 2011. The annual glaciohydrology cycle in the ablation zone of the Greenland Ice Sheet: Part 1. hydrology model. Journal of Glaciology. 57: 697-709. doi:10.3189/002214311797409668. [web] [.pdf]

4. T. Phillips, S. Leyk, H. Rajaram, W. Colgan, W. Abdalati, D. McGrath and K. Steffen. 2011. Modeling moulin distribution on Sermeq Avannarleq glacier using ASTER and WorldView imagery and fuzzy set theory. Remote Sensing of Environment. 115: 2292-2301. doi:10.1016/j.rse.2011.04.029. [web] [.pdf]

3. B. Balsley, L. Kantha and W. Colgan. 2010. On the use of Slow Ascent Meter-scale Sampling (SAMS) radiosondes for observing overturning events in the free atmosphere. Journal of Atmospheric and Oceanic Technology. 27: 766-775. doi:10.1175/2009JTECHA1310.1. [web] [.pdf]

2. W. Colgan, J. Davis and M. Sharp. 2008. Is the high-elevation region of Devon Ice Cap thickening? Journal of Glaciology. 54: 428-436. doi:10.3189/002214308785837084. [web] [.pdf]

1. W. Colgan and M. Sharp. 2008. Combined oceanic and atmospheric influences on net accumulation on the Devon Island Ice Cap, Nunavut, Canada. Journal of Glaciology. 54: 28-40. doi:10.3189/002214308784409044. [web] [.pdf]

W. Colgan. 2011. Modeling the influence of surface meltwater on the ice dynamics of the Greenland Ice Sheet. Ph.D. Thesis. University of Colorado. [.pdf]

W. Colgan. 2007. Reconstructing the recent accumulation history and mass balance trends for high elevation regions of the Devon Island Ice Cap in the Canadian Arctic. M.Sc. Thesis. University of Alberta. [.pdf]

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