TY - JOUR
T1 - Atmosphere-ocean-ice interactions in the Amundsen Sea Embayment, West Antarctica
AU - Turner, John
AU - Orr, Andrew
AU - Gudmundsson, G. Hilmar
AU - Jenkins, Adrian
AU - Bingham, Robert G.
AU - Hillenbrand, Claus-Dieter
AU - Bracegirdle, Thomas J.
PY - 2017/3/20
Y1 - 2017/3/20
N2 - Over recent decades outlet glaciers of the Amundsen Sea Embayment (ASE), West Antarctica, have accelerated, thinned, and retreated, and are now contributing approximately 10% to global sea level rise. All the ASE glaciers flow into ice shelves, and it is the thinning of these since the 1970s, and their ungrounding from “pinning points” that is widely held to be responsible for triggering the glaciers' decline. These changes have been linked to the inflow of warm Circumpolar Deep Water (CPDW) onto the ASE's continental shelf. CPDW delivery is highly variable and is closely related to the regional atmospheric circulation. The ASE is south of the Amundsen Sea Low (ASL), which has a large variability and which has deepened in recent decades. The ASL is influenced by the phase of the Southern Annular Mode, along with tropical climate variability. It is not currently possible to simulate such complex atmosphere-ocean-ice interactions in models, hampering prediction of future change. The current retreat could mark the beginning of an unstable phase of the ASE glaciers that, if continued, will result in collapse of the West Antarctic Ice Sheet, but numerical ice sheet models currently lack the predictive power to answer this question. It is equally possible that the recent retreat will be short-lived and that the ASE will find a new stable state. Progress is hindered by incomplete knowledge of bed topography in the vicinity of the grounding line. Furthermore, a number of key processes are still missing or poorly represented in models of ice-flow.
AB - Over recent decades outlet glaciers of the Amundsen Sea Embayment (ASE), West Antarctica, have accelerated, thinned, and retreated, and are now contributing approximately 10% to global sea level rise. All the ASE glaciers flow into ice shelves, and it is the thinning of these since the 1970s, and their ungrounding from “pinning points” that is widely held to be responsible for triggering the glaciers' decline. These changes have been linked to the inflow of warm Circumpolar Deep Water (CPDW) onto the ASE's continental shelf. CPDW delivery is highly variable and is closely related to the regional atmospheric circulation. The ASE is south of the Amundsen Sea Low (ASL), which has a large variability and which has deepened in recent decades. The ASL is influenced by the phase of the Southern Annular Mode, along with tropical climate variability. It is not currently possible to simulate such complex atmosphere-ocean-ice interactions in models, hampering prediction of future change. The current retreat could mark the beginning of an unstable phase of the ASE glaciers that, if continued, will result in collapse of the West Antarctic Ice Sheet, but numerical ice sheet models currently lack the predictive power to answer this question. It is equally possible that the recent retreat will be short-lived and that the ASE will find a new stable state. Progress is hindered by incomplete knowledge of bed topography in the vicinity of the grounding line. Furthermore, a number of key processes are still missing or poorly represented in models of ice-flow.
U2 - 10.1002/2016RG000532
DO - 10.1002/2016RG000532
M3 - Article
SN - 8755-1209
VL - 55
SP - 235
EP - 276
JO - Reviews of Geophysics
JF - Reviews of Geophysics
ER -