@article {oct, title = {Sensitivity of Pine Island Glacier to observed ocean forcing}, journal = {Geophysical Research Letters}, volume = {43}, year = {2016}, month = {oct}, pages = {10,817{\textendash}10,825}, abstract = {{\textcopyright}2016. American Geophysical Union. All Rights Reserved.We present subannual observations (2009{\textendash}2014) of a major West Antarctic glacier (Pine Island Glacier) and the neighboring ocean. Ongoing glacier retreat and accelerated ice flow were likely triggered a few decades ago by increased ocean-induced thinning, which may have initiated marine ice sheet instability. Following a subsequent 60{\%} drop in ocean heat content from early 2012 to late 2013, ice flow slowed, but by {\textless} 4{\%}, with flow recovering as the ocean warmed to prior temperatures. During this cold-ocean period, the evolving glacier-bed/ice shelf system was also in a geometry favorable to stabilization. However, despite a minor, temporary decrease in ice discharge, the basin-wide thinning signal did not change. Thus, as predicted by theory, once marine ice sheet instability is underway, a single transient high-amplitude ocean cooling has only a relatively minor effect on ice flow. The long-term effects of ocean temperature variability on ice flow, however, are not yet known.}, keywords = {glacier-ocean interactions, Ice Dynamics, ice shelves, ice streams, marine ice sheet instability}, issn = {00948276}, doi = {10.1002/2016GL070500}, url = {http://doi.wiley.com/10.1002/2016GL070500}, author = {Christianson, Knut and Bushuk, Mitchell and Dutrieux, Pierre and Parizek, Byron R. and Joughin, Ian R. and Alley, Richard B. and Shean, David E. and Abrahamsen, E. Povl and Anandakrishnan, Sridhar and Heywood, Karen J. and Kim, Tae-Wan and Lee, Sang Hoon and Nicholls, Keith and Stanton, Tim and Truffer, Martin and Webber, Benjamin G. M. and Jenkins, Adrian and Jacobs, Stan and Bindschadler, Robert and Holland, David M.} } @article {204, title = {Summer melt regulates winter glacier flow speeds throughout Alaska}, journal = {Geophysical Research Letters}, year = {2013}, abstract = {Predicting how climate change will affect glacier and ice sheet flow speeds remains a large hurdle towards accurate sea level rise forecasting. Increases in surface melt rates are known to accelerate glacier flow in summer, whereas in winter, flow speeds are believed to be relatively invariant. Here we show that wintertime flow speeds on nearly all major glaciers throughout Alaska are not only variable but are inversely related to melt from preceding summers. For each additional meter of summertime melt, we observe an 11\% decrease in wintertime velocity on glaciers of all sizes, geometries, climates and bed types. This dynamic occurs because inter-annual differences in summertime melt affect how much water is retained in the sub-glacial system during winter. The ubiquity of the dynamic indicates it occurs globally on glaciers and ice sheets not frozen to their beds and thus constitutes a new mechanism affecting sea level rise projections.}, keywords = {Alaska, Ice Dynamics, Mountain Glaciers, Offset Tracking, Sub-Glacial Hydrology, Winter}, issn = {1944-8007}, doi = {10.1002/2013GL058228}, url = {http://dx.doi.org/10.1002/2013GL058228}, author = {Evan W. Burgess and Chris F. Larsen and Richard R. Forster} }