@article{MengelFeldmannLevermann2016, author = {Mengel, Matthias and Feldmann, Johannes and Levermann, Anders}, title = {Linear sea-level response to abrupt ocean warming of major West Antarctic ice basin}, series = {Nature climate change}, volume = {6}, journal = {Nature climate change}, publisher = {Nature Publ. Group}, address = {London}, issn = {1758-678X}, doi = {10.1038/NCLIMATE2808}, pages = {71 -- +}, year = {2016}, abstract = {Antarctica's contribution to global sea-level rise has recently been increasing1. Whether its ice discharge will become unstable and decouple from anthropogenic forcing2,3,4 or increase linearly with the warming of the surrounding ocean is of fundamental importance5. Under unabated greenhouse-gas emissions, ocean models indicate an abrupt intrusion of warm circumpolar deep water into the cavity below West Antarctica's Filchner-Ronne ice shelf within the next two centuries6,7. The ice basin's retrograde bed slope would allow for an unstable ice-sheet retreat8, but the buttressing of the large ice shelf and the narrow glacier troughs tend to inhibit such instability9,10,11. It is unclear whether future ice loss will be dominated by ice instability or anthropogenic forcing. Here we show in regional and continental-scale ice-sheet simulations, which are capable of resolving unstable grounding-line retreat, that the sea-level response of the Filchner-Ronne ice basin is not dominated by ice instability and follows the strength of the forcing quasi-linearly. We find that the ice loss reduces after each pulse of projected warm water intrusion. The long-term sea-level contribution is approximately proportional to the total shelf-ice melt. Although the local instabilities might dominate the ice loss for weak oceanic warming12, we find that the upper limit of ice discharge from the region is determined by the forcing and not by the marine ice-sheet instability.}, language = {en} } @article{FeldmannLevermannMengel2019, author = {Feldmann, Johannes and Levermann, Anders and Mengel, Matthias}, title = {Stabilizing the West Antarctic Ice Sheet by surface mass deposition}, series = {Science Advances}, volume = {5}, journal = {Science Advances}, number = {7}, publisher = {American Assoc. for the Advancement of Science}, address = {Washington}, issn = {2375-2548}, doi = {10.1126/sciadv.aaw4132}, pages = {7}, year = {2019}, abstract = {There is evidence that a self-sustaining ice discharge from the West Antarctic Ice Sheet (WAIS) has started, potentially leading to its disintegration. The associated sea level rise of more than 3m would pose a serious challenge to highly populated areas including metropolises such as Calcutta, Shanghai, New York City, and Tokyo. Here, we show that the WAIS may be stabilized through mass deposition in coastal regions around Pine Island and Thwaites glaciers. In our numerical simulations, a minimum of 7400 Gt of additional snowfall stabilizes the flow if applied over a short period of 10 years onto the region (-2 mm year(-1) sea level equivalent). Mass deposition at a lower rate increases the intervention time and the required total amount of snow. We find that the precise conditions of such an operation are crucial, and potential benefits need to be weighed against environmental hazards, future risks, and enormous technical challenges.}, language = {en} }