Staff profile

• 2024 - Present: Postdoctoral Research Associate, Durham University, UK
• 2022 - 2024: Aspiration 2030 Postdoctoral Fellow, University of Victoria, Canada
• 2020 - 2022: Postdoctoral Research Associate, University of Texas at San Antonio, USA
• 2014 - 2019: PhD (NASA Earth & Space Science Fellow) Geophysical Sciences, University of Chicago, USA
• 2012 - 2013: MPhil Polar Studies, University of Cambridge, UK
• 2011 - 2012: Field & Research Assistant, Centro de Estudios Avanzados en Zonas Áridas, Chile
• 2007 - 2011: BSc (Hons) Geography, University of Edinburgh, UK

Research Interests

• Emperor penguins
• Sea ice
• Ice shelves
• Earth observation
• Antarctic & Arctic

My current research is primarily focused on investigating how changing ice conditions in Antarctica impact emperor penguins, in order to better understand how they are being affected by climate change. I do this using satellite remote sensing to analyse colonies around the continent, alongside changes in sea ice and glaciers.

I also have a keen interest in sea ice and ice shelves at both poles, particularly using remote sensing to better understand their state and how this is changing in a warming climate. I have published work using SAR to investigate Arctic sea ice, polynyas in Antarctica, and ice-shelf stability and hydrology at both poles.

I am broadly interested in how the cryosphere impacts the natural world and humans, including implications for conservation, Arctic communities, sea level, and the wider climate system. Through these interests I have presented work at United Nations Climate Change Conferences (COP).

I can be found on BlueSky at @geogeordie.bsky.social.

Journal Article

• Seasonal and Interannual Variations in Sea Ice Thickness in the Weddell Sea, Antarctica (2019–2022) Using ICESat-2
  
  Joshi, M., Mestas-Nuñez, A. M., Ackley, S. F., Arndt, S., Macdonald, G. J., & Haas, C. (2024). Seasonal and Interannual Variations in Sea Ice Thickness in the Weddell Sea, Antarctica (2019–2022) Using ICESat-2. Remote Sensing, 16(20), Article 3909. https://doi.org/10.3390/rs16203909
• Arctic Sea Ice Topography Information From RADARSAT Constellation Mission (RCM) Synthetic Aperture Radar (SAR) Backscatter
  
  Macdonald, G. J., Scharien, R. K., Duncan, K., Farrell, S. L., Rezania, P., & Tavri, A. (2024). Arctic Sea Ice Topography Information From RADARSAT Constellation Mission (RCM) Synthetic Aperture Radar (SAR) Backscatter. Geophysical Research Letters, 51(4), Article e2023GL107261. https://doi.org/10.1029/2023gl107261
• Evolution of the dynamics, area, and ice production of the Amundsen Sea Polynya, Antarctica, 2016–2021
  
  Macdonald, G. J., Ackley, S. F., Mestas-Nuñez, A. M., & Blanco-Cabanillas, A. (2023). Evolution of the dynamics, area, and ice production of the Amundsen Sea Polynya, Antarctica, 2016–2021. The Cryosphere, 17(2), 457-476. https://doi.org/10.5194/tc-17-457-2023
• Semi-automated tracking of iceberg B43 using Sentinel-1 SAR images via Google Earth Engine
  
  Koo, Y., Xie, H., Ackley, S. F., Mestas-Nuñez, A. M., Macdonald, G. J., & Hyun, C. (2021). Semi-automated tracking of iceberg B43 using Sentinel-1 SAR images via Google Earth Engine. The Cryosphere, 15(10), 4727-4744. https://doi.org/10.5194/tc-15-4727-2021
• Treatment of ice-shelf evolution combining flow and flexure
  
  MacAyeal, D. R., Sergienko, O. V., Banwell, A. F., Macdonald, G. J., Willis, I. C., & Stevens, L. A. (2021). Treatment of ice-shelf evolution combining flow and flexure. Journal of Glaciology, 67(265), 885-902. https://doi.org/10.1017/jog.2021.39
• Formation of sea ice ponds from ice-shelf runoff, adjacent to the McMurdo Ice Shelf, Antarctica
  
  Macdonald, G. J., Popović, P., & Mayer, D. P. (2020). Formation of sea ice ponds from ice-shelf runoff, adjacent to the McMurdo Ice Shelf, Antarctica. Annals of Glaciology, 61(82), 73-77. https://doi.org/10.1017/aog.2020.9
• Diurnal lake-level cycles on ice shelves driven by meltwater input and ocean tidal tilt
  
  MacAyeal, D. R., Willis, I. C., Banwell, A. F., Macdonald, G. J., & Goodsell, B. (2020). Diurnal lake-level cycles on ice shelves driven by meltwater input and ocean tidal tilt. Journal of Glaciology, 66(256), 231-247. https://doi.org/10.1017/jog.2019.98
• Diurnal seismicity cycle linked to subsurface melting on an ice shelf
  
  MacAyeal, D. R., Banwell, A. F., Okal, E. A., Lin, J., Willis, I. C., Goodsell, B., & MacDonald, G. J. (2019). Diurnal seismicity cycle linked to subsurface melting on an ice shelf. Annals of Glaciology, 60(79), 137-157. https://doi.org/10.1017/aog.2018.29
• Formation of pedestalled, relict lakes on the McMurdo Ice Shelf, Antarctica
  
  MACDONALD, G. J., BANWELL, A. F., WILLIS, I. C., MAYER, D. P., GOODSELL, B., & MacAYEAL, D. R. (2019). Formation of pedestalled, relict lakes on the McMurdo Ice Shelf, Antarctica. Journal of Glaciology, 65(250), 337-343. https://doi.org/10.1017/jog.2019.17
• Direct measurements of ice-shelf flexure caused by surface meltwater ponding and drainage
  
  Banwell, A. F., Willis, I. C., Macdonald, G. J., Goodsell, B., & MacAyeal, D. R. (2019). Direct measurements of ice-shelf flexure caused by surface meltwater ponding and drainage. Nature Communications, 10(1). https://doi.org/10.1038/s41467-019-08522-5
• Seasonal evolution of supraglacial lakes on a floating ice tongue, Petermann Glacier, Greenland
  
  Macdonald, G. J., Banwell, A. F., & MacAyeal, D. R. (2018). Seasonal evolution of supraglacial lakes on a floating ice tongue, Petermann Glacier, Greenland. Annals of Glaciology, 59(76pt1), 56-65. https://doi.org/10.1017/aog.2018.9
• Calving and rifting on the McMurdo Ice Shelf, Antarctica
  
  Banwell, A. F., Willis, I. C., Macdonald, G. J., Goodsell, B., Mayer, D. P., Powell, A., & Macayeal, D. R. (2017). Calving and rifting on the McMurdo Ice Shelf, Antarctica. Annals of Glaciology, 58(75pt1), 78-87. https://doi.org/10.1017/aog.2017.12