We demonstrate that a mid-twentieth century decrease in geopotential height in the southwest Pacific marks a Rossby wave response to equatorial Pacific warming, leading to enhanced easterly airflow off George V Land. Our results suggest that in contrast to ozone hole-driven changes in the Amundsen Sea, the 1979–2015 increase in sea ice extent off George V Land may be in response to reduced northward Ekman drift and enhanced (near-coast) production as a consequence of low latitude forcing.
We demonstrate that a mid-twentieth century decrease in geopotential height in the southwest...
1Climate Change Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Australia
2Palaeontology, Geobiology and Earth Archives Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Australia
3Australian Antarctic Division, 203 Channel Highway, Kingston 7050, Tasmania, Australia
4Antarctic Climate & Ecosystems Cooperative Research Centre, University of Tasmania, Private Bag 80, Hobart, Tasmania 7001
5Earth System Science and Departement Geografie, Vrije Universiteit Brussels, Belgium
6Université catholique de Louvain, Earth and Life Institute, Georges Lemaître Centre for Earth and Climate Research, Place Pasteur, 3, 1348 Louvain-la-Neuve, Belgium
7Cryospheric Sciences Laboratory/Code 615, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
8Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309, USA
9Physical Sciences Division, Earth System Research Laboratory, NOAA, Boulder, CO 80305, USA
10Meteorologist at the Antarctic Meteorological Research Center, Space Science and Engineering Center, University of Wisconsin–Madison, Madison, WI, USA
11Department of Physical Sciences, School of Arts and Sciences, Madison Area Technical College, Madison, WI, USA
12Met Office Hadley Centre, Exeter, UK
13Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Australia
14Sydney Institute of Marine Science, Chowder Bay Road, Mosman NSW 2088, Australia
15Centre for Bio-Innovation Science, School of Biological, Earth and Environmental Sciences, University of New South Wales, Australia
1Climate Change Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Australia
2Palaeontology, Geobiology and Earth Archives Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Australia
3Australian Antarctic Division, 203 Channel Highway, Kingston 7050, Tasmania, Australia
4Antarctic Climate & Ecosystems Cooperative Research Centre, University of Tasmania, Private Bag 80, Hobart, Tasmania 7001
5Earth System Science and Departement Geografie, Vrije Universiteit Brussels, Belgium
6Université catholique de Louvain, Earth and Life Institute, Georges Lemaître Centre for Earth and Climate Research, Place Pasteur, 3, 1348 Louvain-la-Neuve, Belgium
7Cryospheric Sciences Laboratory/Code 615, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
8Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309, USA
9Physical Sciences Division, Earth System Research Laboratory, NOAA, Boulder, CO 80305, USA
10Meteorologist at the Antarctic Meteorological Research Center, Space Science and Engineering Center, University of Wisconsin–Madison, Madison, WI, USA
11Department of Physical Sciences, School of Arts and Sciences, Madison Area Technical College, Madison, WI, USA
12Met Office Hadley Centre, Exeter, UK
13Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Australia
14Sydney Institute of Marine Science, Chowder Bay Road, Mosman NSW 2088, Australia
15Centre for Bio-Innovation Science, School of Biological, Earth and Environmental Sciences, University of New South Wales, Australia
Received: 29 Mar 2017 – Accepted for review: 21 Apr 2017 – Discussion started: 25 Apr 2017
Abstract. Satellite observations demonstrate Antarctic sea ice extent increased between late-1978 and 2015, with significant spatial and seasonal variability. Late spring retreat off George V Land is a major component of the observed increase, but the paucity of proxy records makes interpretation of trends (and impacts) challenging. Here Earth-system modelling and reanalysis demonstrate tropical Pacific warming can trigger an atmospheric Rossby wave response during the austral spring, delaying sea-ice retreat off George V Land. Our results provide new insights into the spatial and temporal role low latitudes play in Antarctic sea-ice production, drift and ocean circulation on decadal to centennial timescales.
We demonstrate that a mid-twentieth century decrease in geopotential height in the southwest Pacific marks a Rossby wave response to equatorial Pacific warming, leading to enhanced easterly airflow off George V Land. Our results suggest that in contrast to ozone hole-driven changes in the Amundsen Sea, the 1979–2015 increase in sea ice extent off George V Land may be in response to reduced northward Ekman drift and enhanced (near-coast) production as a consequence of low latitude forcing.
We demonstrate that a mid-twentieth century decrease in geopotential height in the southwest...
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