@article{12586,
  abstract     = {Ice cliffs are common on debris-covered glaciers and have relatively high melt rates due to their direct exposure to incoming radiation. Previous studies have shown that their number and relative area can change considerably from year to year, but this variability has not been explored, in part because available cliff observations are irregular. Here, we systematically mapped and tracked ice cliffs across four debris-covered glaciers in High Mountain Asia for every late ablation season from 2009 to 2019 using high-resolution multi-spectral satellite imagery. We then quantified the processes occurring at the feature scale to train a stochastic birth-death model to represent the cliff population dynamics. Our results show that while the cliff relative area can change by up to 20% from year to year, the natural long-term variability is constrained, thus defining a glacier-specific cliff carrying capacity. In a subsequent step, the inclusion of external drivers related to climate, glacier dynamics, and hydrology highlights the influence of these variables on the cliff population dynamics, which is usually not a direct one due to the complexity and interdependence of the processes taking place at the glacier surface. In some extreme cases (here, a glacier surge), these external drivers may lead to a reorganization of the cliffs at the glacier surface and a change in the natural variability. These results have implications for the melt of debris-covered glaciers, in addition to showing the high rate of changes at their surface and highlighting some of the links between cliff population and glacier state.},
  author       = {Kneib, M. and Miles, E. S. and Buri, P. and Molnar, P. and McCarthy, M. and Fugger, S. and Pellicciotti, Francesca},
  issn         = {2169-9003},
  journal      = {Journal of Geophysical Research: Earth Surface},
  keywords     = {Earth-Surface Processes, Geophysics},
  number       = {10},
  publisher    = {American Geophysical Union},
  title        = {{Interannual dynamics of ice cliff populations on debris‐covered glaciers from remote sensing observations and stochastic modeling}},
  doi          = {10.1029/2021jf006179},
  volume       = {126},
  year         = {2021},
}

@article{12613,
  abstract     = {We use high-resolution digital elevation models (DEMs) from unmanned aerial vehicle (UAV) surveys to document the evolution of four ice cliffs on the debris-covered tongue of Lirung Glacier, Nepal, over one ablation season. Observations show that out of four cliffs, three different patterns of evolution emerge: (i) reclining cliffs that flatten during the ablation season; (ii) stable cliffs that maintain a self-similar geometry; and (iii) growing cliffs, expanding laterally. We use the insights from this unique data set to develop a 3-D model of cliff backwasting and evolution that is validated against observations and an independent data set of volume losses. The model includes ablation at the cliff surface driven by energy exchange with the atmosphere, reburial of cliff cells by surrounding debris, and the effect of adjacent ponds. The cliff geometry is updated monthly to account for the modifications induced by each of those processes. Model results indicate that a major factor affecting the survival of steep cliffs is the coupling with ponded water at its base, which prevents progressive flattening and possible disappearance of a cliff. The radial growth observed at one cliff is explained by higher receipts of longwave and shortwave radiation, calculated taking into account atmospheric fluxes, shading, and the emission of longwave radiation from debris surfaces. The model is a clear step forward compared to existing static approaches that calculate atmospheric melt over an invariant cliff geometry and can be used for long-term simulations of cliff evolution and to test existing hypotheses about cliffs' survival.},
  author       = {Buri, Pascal and Miles, Evan S. and Steiner, Jakob F. and Immerzeel, Walter W. and Wagnon, Patrick and Pellicciotti, Francesca},
  issn         = {2169-9011},
  journal      = {Journal of Geophysical Research: Earth Surface},
  keywords     = {Earth-Surface Processes, Geophysics},
  number       = {12},
  pages        = {2471--2493},
  publisher    = {American Geophysical Union},
  title        = {{A physically based 3‐D model of ice cliff evolution over debris‐covered glaciers}},
  doi          = {10.1002/2016jf004039},
  volume       = {121},
  year         = {2016},
}