Subglacial and englacial hydrology

Our planet’s large ice masses act as vast reservoirs of fresh water, and their hydrology has wide-ranging influence. Many mountain glaciers serve as a direct resource of water for habitation, for irrigation, and for hydro-power generation. Hydrological processes are fundamental to the understanding of glacial erosion and landform development, and they produce catastrophic flood risks that demand attention from both regional and national planners. The hydrological systems of glaciers and ice sheets play a major role in the dynamics of the ice itself, providing strong controls on basal sliding, crevasse formation, and the mass and thermal balances at the ice surface. Meltwater runoff from ice sheets has potentially profound effects on ocean circulation and marine ecology, as well as its obvious effect on sea level.

Since a couple of years I am very interested in the advancement of subglacial (below a glacier) and englacial (inside a glacier’s ice body) hydrology models. All really started when I worked on a supraglacial¬† (on the glacier surface) and englacial meltwater stream model that predicts the evolution of such streams (Jarosch and Gudmundsson, 2012). Check out the accompanying video below to see what the model does and consider reading the whole paper should you get more interested in that work.

These days I focus on the formation and evolution of englacial channels as well as subglacial water pathways. In the above mentioned 2012 paper I concluded with the following outlook: “Currently the model is limited to simulate cases of open channel flow. A useful future expansion of the model would be to simulate the meltwater flow within the channel explicitly in a FEM simulation and couple it to the existing model. This would enable an explicit simulation of heat transfer processes at the water-ice boundary, which would allow for an evaluation of our melt rate distribution scheme and would be crucial for the treatment of cold ice conditions. A welcomed benefit would be to explicitly model the transition from open to pressurized channel flow. The simulation of fully developed turbulent water flow in channels and pipes is a numerically complex and difficult task, especially in the case of free surface flow, so this model extension remains a challenge for future research.”

As it turns out in 2016 it is not that difficult anymore, however the finite volume method makes one’s life a lot easier in comparison to the finite element approach. Below you can find a list with links to the individual sub-pages of my ongoing projects:

  • J√∂kulhlaup initiation and channel formation (page under construction)
  • Heat transfer in englacial channels (page under construction)