Joel Harper

Department of Geosciences, University of Montana


Since I started at UM 6 years ago, my research has focused on three general areas of cryosphere and climate.


1. Ice Dynamics and Basal Processes

The mechanics of how glaciers move is fundamental to projecting future sea level rise, and to understanding all other aspects of glacier-climate interactions. My research has addressed many different issues, but my current focus is on how water at the bed of glaciers and ice sheets influences sliding motion. Research methods include detailed field measurements, data analysis, and numerical modeling. A major project currently underway involves drilling to the bed of the Greenland Ice Sheet to install sensors for monitoring water flow and ice motion. Funding for this work is from NSF-OPP-ANS and a Swedish-Finish-Canadian consortium.


A few pubs on this work…

Harper, J.T., Bradford, J.H., Humphrey, N.F., and T.W. Meierbachtol,  (2010), Vertical Extension of the Subglacial Drainage System Into Basal Crevasses, Nature, V 467, 579-582, doi:10.1038/nature09398.

Harper, J. T., N. F. Humphrey, W. T. Pfeffer, and B. Lazar (2007), Two modes of Accelerated Glacier Sliding Related to Water, Geophysical Research Letters, 34(12), L12503, doi:12510.11029/12007GL030233.

Fudge, T. J., Harper, J. T., Humphrey, N. F. & Pfeffer, W. T. Rapid Glacier Sliding, Reverse Ice Motion, and Subglacial Water Pressure During an Autumn Rainstorm. Annals of Glaciology 50, 1-9 (2009).


Hot water drilling to study the bed of Bench Glacier, Alaska.


2. Snow/Ice and Climate Processes

Glacier and ice sheet mass balance is important to issues related to sea level rise and water resources. Current research in this area is focused on melt water infiltration and runoff from the Greenland Ice Sheet, and glacier-climate interaction on small mountain glaciers in Montana. Funding for this work is from NSF-OPP-ANS, INRA and the USGS.

A few pubs on this work…

Pfeffer, W. T., J. T. Harper, and S. O'Neel (2008), Kinematic constraints on glacier contributions to 21st-century sea-level rise, Science, 321(5894), 1340-1343.

Brown, J., Harper, J., Pfeffer, W., Humphrey, N., and J. Bradford, (in press), High Resolution Study of Layering within the Percolation and Soaked Facies of the Greenland Icesheet, Annals of Glaciology.

Brown, J., Harper, J., (in press), Cirque Glacier Sensitivity to 21st Century Climate Change: Sperry Glacier, Montana, Global and Planetary Change.


Home for a month every summer – the Greenland Ice Sheet.

3. Seasonal Snow and Climate Change

In the mountain west, the seasonal snowpack is the most important reservoir for much needed late season water. My work is focused on how snow is distributed across large-scale mountain landscapes, and the potential vulnerable of this snow to climate change. This research involves field work, data analysis, and numerical modeling. This work is funded by NSF-Hydrology and INRA.

A few pubs on this work…

Gillan, B., Harper, J., and Moore, J., (2010) Timing of present and future snowmelt from high elevations of NW Montana, Water Resources Research, 46, W01507, doi:10.1029/2009WR007861.

Bradford, J. H., J. T. Harper, and J. Brown (2009), Complex dielectric permittivity measurements from ground-penetrating radar data to estimate snow liquid water content in the pendular regime, Water Resources Research, 45, 1-12, doi: 10.1029/2008WR007341.

Moore, J. N., J. T. Harper, and M. C. Greenwood (2007), Significance of trends toward earlier snowmelt runoff, Columbia and Missouri Basin headwaters, western United States, Journal of Geophysical Research, 34, L16402, doi:16410.11029/12007GL031022.



Field measurement of snow properties – Montana.