I'm a scientist who studies ice & snow, preferably by engineering better observations. I've contributed to (or led) measurements in: Greenland, the Central Arctic, Alaska, the Colorado mountains, and the Beaufort Gyre. While I mostly look at the Arctic, I'm also interested in just about any place or thing that is cold. Which... might be environmental determinism. I'm currently based in Colorado, with laboratories at NOAA and NSIDC. Although lately I spend a lot of time in Leeds too. I believe that better in situ observations will blaze new trails to a more complete understanding of the Arctic. But truthfully, I just like making things and taking pictures. Since really the truth is just a plain picture and what is a picture but an observation anyway.


Photography
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"The Observers"
— How do we make measurements? -
"Greenland"
— On and around the ice sheet -
"Alaska"
— Summer on the North Slope -
"Sea Ice"
— Photos from the central Arctic Ocean
Work I'm Particularly Proud Of
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Impacts of Atmospheric Rivers in Central Greenland: Snowfall, Clouds, and Atmospheric State
— A. E. Wedum, C. Pettersen, H. Guy, M. R. Gallagher, et al. Journal of Geophysical Research: Atmospheres, 2026. 10.1029/2025JD044309 -
Observations of surface energy fluxes and meteorology in the seasonally snow-covered high-elevation East River watershed during SPLASH, 2021–2023
— C. J. Cox, J. M. Intrieri, B. J. Butterworth, G. de Boer, et al. Earth System Science Data, 2025. 10.5194/essd-17-1481-2025 -
Warm Temperature Extremes Across Greenland Connected to Clouds
— M. R. Gallagher, H. Chepfer, M. D. Shupe, R. Guzman. Geophysical Research Letters, 2020. 10.1029/2019GL086059