@article{PattynPerichonDurandetal.2013, author = {Pattyn, Frank and Perichon, Laura and Durand, Gael and Favier, Lionel and Gagliardini, Olivier and Hindmarsh, Richard C. A. and Zwinger, Thomas and Albrecht, Torsten and Cornford, Stephen and Docquier, David and Furst, Johannes J. and Goldberg, Daniel and Gudmundsson, Gudmundur Hilmar and Humbert, Angelika and Huetten, Moritz and Huybrechts, Philippe and Jouvet, Guillaume and Kleiner, Thomas and Larour, Eric and Martin, Daniel and Morlighem, Mathieu and Payne, Anthony J. and Pollard, David and Rueckamp, Martin and Rybak, Oleg and Seroussi, Helene and Thoma, Malte and Wilkens, Nina}, title = {Grounding-line migration in plan-view marine ice-sheet models: results of the ice2sea MISMIP3d intercomparison}, series = {Journal of glaciology}, volume = {59}, journal = {Journal of glaciology}, number = {215}, publisher = {International Glaciological Society}, address = {Cambridge}, issn = {0022-1430}, doi = {10.3189/2013JoG12J129}, pages = {410 -- 422}, year = {2013}, abstract = {Predictions of marine ice-sheet behaviour require models able to simulate grounding-line migration. We present results of an intercomparison experiment for plan-view marine ice-sheet models. Verification is effected by comparison with approximate analytical solutions for flux across the grounding line using simplified geometrical configurations (no lateral variations, no buttressing effects from lateral drag). Perturbation experiments specifying spatial variation in basal sliding parameters permitted the evolution of curved grounding lines, generating buttressing effects. The experiments showed regions of compression and extensional flow across the grounding line, thereby invalidating the boundary layer theory. Steady-state grounding-line positions were found to be dependent on the level of physical model approximation. Resolving grounding lines requires inclusion of membrane stresses, a sufficiently small grid size (<500 m), or subgrid interpolation of the grounding line. The latter still requires nominal grid sizes of <5 km. For larger grid spacings, appropriate parameterizations for ice flux may be imposed at the grounding line, but the short-time transient behaviour is then incorrect and different from models that do not incorporate grounding-line parameterizations. The numerical error associated with predicting grounding-line motion can be reduced significantly below the errors associated with parameter ignorance and uncertainties in future scenarios.}, language = {en} } @article{NowickiBindschadlerAbeOuchietal.2013, author = {Nowicki, Sophie and Bindschadler, Robert A. and Abe-Ouchi, Ayako and Aschwanden, Andy and Bueler, Ed and Choi, Hyeungu and Fastook, Jim and Granzow, Glen and Greve, Ralf and Gutowski, Gail and Herzfeld, Ute and Jackson, Charles and Johnson, Jesse and Khroulev, Constantine and Larour, Eric and Levermann, Anders and Lipscomb, William H. and Martin, Maria A. and Morlighem, Mathieu and Parizek, Byron R. and Pollard, David and Price, Stephen F. and Ren, Diandong and Rignot, Eric and Saito, Fuyuki and Sato, Tatsuru and Seddik, Hakime and Seroussi, Helene and Takahashi, Kunio and Walker, Ryan and Wang, Wei Li}, title = {Insights into spatial sensitivities of ice mass response to environmental change from the SeaRISE ice sheet modeling project II Greenland}, series = {Journal of geophysical research : Earth surface}, volume = {118}, journal = {Journal of geophysical research : Earth surface}, number = {2}, publisher = {American Geophysical Union}, address = {Washington}, issn = {2169-9003}, doi = {10.1002/jgrf.20076}, pages = {1025 -- 1044}, year = {2013}, abstract = {The Sea-level Response to Ice Sheet Evolution (SeaRISE) effort explores the sensitivity of the current generation of ice sheet models to external forcing to gain insight into the potential future contribution to sea level from the Greenland and Antarctic ice sheets. All participating models simulated the ice sheet response to three types of external forcings: a change in oceanic condition, a warmer atmospheric environment, and enhanced basal lubrication. Here an analysis of the spatial response of the Greenland ice sheet is presented, and the impact of model physics and spin-up on the projections is explored. Although the modeled responses are not always homogeneous, consistent spatial trends emerge from the ensemble analysis, indicating distinct vulnerabilities of the Greenland ice sheet. There are clear response patterns associated with each forcing, and a similar mass loss at the full ice sheet scale will result in different mass losses at the regional scale, as well as distinct thickness changes over the ice sheet. All forcings lead to an increased mass loss for the coming centuries, with increased basal lubrication and warmer ocean conditions affecting mainly outlet glaciers, while the impacts of atmospheric forcings affect the whole ice sheet.}, language = {en} }