Sensitivity of Pine Island Glacier to observed ocean forcing

• Main Authors: Christianson, Knut, Holland, David M., Bindschadler, Robert, Jacobs, Stan, Jenkins, Adrian, Webber, Benjamin G.M., Truffer, Martin, Stanton, Timothy P., Nicholls, Keith, Lee, Sang Hoon, Kim, Tae-Wan, Heywood, Karen J., Bushuk, Mitchell, Shean, David E., Parizek, Byron R., Joughin, Ian R., Anandakrishnan, Sridhar, Alley, Richard B., Dutrieux, Pierre, Abrahamsen, E. Povl
• Other Authors: Naval Postgraduate School (U.S.), Oceanography
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: AGU Publications 2016
• Subjects: Pine Island Glacier speed is correlated with ocean temperature; Grounded ice speed slowed by only ~1% despite ~60% drop in ocean heat content; Ice speed recovered after the cold-ocean anomaly ended; Antarctic; Pine Island Glacier; Southern Ocean; Antarc*; Ice Sheet; Ice Shelf
• Online Access: https://hdl.handle.net/10945/57135

The article of record as published may be found at http://dx.doi.org/10.1002/2016GL070500 GPS data are archived with UNAVCO (www.unavco.org). Oceanographic data have been submitted to the NOAA National Centers for Environmental Information (https:// www.nodc.noaa.gov/), British Oceanographic Data Centre (http:// www.bodc.ac.uk/), and IEDA/MGDS Southern Ocean portal (http://www. marine-geo.org/index.php). SARderived ice velocity fields and grounding lines, and basal altimeter range data are freely available from the corresponding author. We present subannual observations (2009–2014) 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 < 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. National Aeronautics and Space Administration grants NNX15AH84G U.S. National Science Foundation grants PLR- 0732869 New York University Abu Dhabi Research Institute grant G1204 U.S. National Science Foundation grants ANT-0424589 U.S. National Science Foundation grants AGS-138832 South Korean Polar Research Institute grant KOPRI PP15020 U.K. Natural Environment Research Council iSTAR program—grants NE/G001367/1 U.K. Natural Environment Research Council iSTAR program—grants NE/J005703/1 ...