SIPEX 2012: extreme sea-ice and atmospheric conditions off East Antarctica
In 2012, Antarctic sea-ice coverage was marked by weak annual-mean climate anomalies that consisted of opposing anomalies early and late in the year (some setting new records) which were interspersed by near-average conditions for most of the austral autumn and winter. Here, we investigate the ocean...
Published in: | Deep Sea Research Part II: Topical Studies in Oceanography |
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Online Access: | https://doi.org/10.1016/j.dsr2.2016.06.015 http://ecite.utas.edu.au/113764 |
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ftunivtasecite:oai:ecite.utas.edu.au:113764 2023-05-15T13:49:03+02:00 SIPEX 2012: extreme sea-ice and atmospheric conditions off East Antarctica Heil, P Stammerjohn, S Reid, P Massom, RA Hutchings, JK 2016 https://doi.org/10.1016/j.dsr2.2016.06.015 http://ecite.utas.edu.au/113764 en eng Pergamon-Elsevier Science Ltd http://dx.doi.org/10.1016/j.dsr2.2016.06.015 Heil, P and Stammerjohn, S and Reid, P and Massom, RA and Hutchings, JK, SIPEX 2012: extreme sea-ice and atmospheric conditions off East Antarctica, Deep-Sea Research II, 131 pp. 7-21. ISSN 0967-0645 (2016) [Refereed Article] http://ecite.utas.edu.au/113764 Earth Sciences Physical Geography and Environmental Geoscience Glaciology Refereed Article PeerReviewed 2016 ftunivtasecite https://doi.org/10.1016/j.dsr2.2016.06.015 2019-12-14T07:05:01Z In 2012, Antarctic sea-ice coverage was marked by weak annual-mean climate anomalies that consisted of opposing anomalies early and late in the year (some setting new records) which were interspersed by near-average conditions for most of the austral autumn and winter. Here, we investigate the ocean-ice-atmosphere system off East Antarctica, prior to and during the Sea Ice Physics and Ecosystems eXperiment [SIPEX] 2012, by exploring relationships between atmospheric and oceanic forcing together with the sea-ice and snow characteristics. During August and September 2012, just prior to SIPEX 2012, atmospheric circulation over the Southern Ocean was near-average, setting up the ocean-ice-atmosphere system for near-average conditions. However, below-average surface pressure and temperature as well as strengthened circumpolar winds prevailed during June and July 2012. This led to a new record (19.4810 6 km 2 ) in maximum Antarctic sea-ice extent recorded in late September. In contrast to the weak circum-Antarctic conditions, the East Antarctic sector (including the SIPEX 2012 region) experienced positive sea-ice extent and concentration anomalies during most of 2012, coincident with negative atmospheric pressure and sea-surface temperature anomalies. Heavily deformed sea ice appeared to be associated with intensified wind stress due to increased cyclonicity as well as an increased influx of sea ice from the east. This increased westward ice flux is likely linked to the break-up of nearly 80% of the Mertz Glacier Tongue in 2010, which strongly modified the coastal configuration and hence the width of the westward coastal current. Combined with favourable atmospheric conditions the associated changed coastal configuration allowed more sea ice to remain within the coastal current at the expense of a reduced northward flow in the region around 141145E. In addition a westward propagating positive anomaly of sea-ice extent from the western Ross Sea during austral winter 2012 has been identified to have fed into the westward current of the SIPEX 2012 region. A pair of large grounded icebergs appears to have modified the local stress state as well as the structure of the ice pack upstream and also towards the Dalton Glacier Tongue. Together with the increased influx of sea ice into the regions, this contributed to the difficulties in navigating the SIPEX 2012 region. Article in Journal/Newspaper Antarc* Antarctic Antarctica East Antarctica ice pack Iceberg* Mertz Glacier Ross Sea Sea ice Southern Ocean eCite UTAS (University of Tasmania) Antarctic Austral Dalton Glacier ENVELOPE(-152.417,-152.417,-77.550,-77.550) East Antarctica Mertz Glacier ENVELOPE(144.500,144.500,-67.667,-67.667) Mertz Glacier Tongue ENVELOPE(145.500,145.500,-67.167,-67.167) Ross Sea Southern Ocean Deep Sea Research Part II: Topical Studies in Oceanography 131 7 21 |
institution |
Open Polar |
collection |
eCite UTAS (University of Tasmania) |
op_collection_id |
ftunivtasecite |
language |
English |
topic |
Earth Sciences Physical Geography and Environmental Geoscience Glaciology |
spellingShingle |
Earth Sciences Physical Geography and Environmental Geoscience Glaciology Heil, P Stammerjohn, S Reid, P Massom, RA Hutchings, JK SIPEX 2012: extreme sea-ice and atmospheric conditions off East Antarctica |
topic_facet |
Earth Sciences Physical Geography and Environmental Geoscience Glaciology |
description |
In 2012, Antarctic sea-ice coverage was marked by weak annual-mean climate anomalies that consisted of opposing anomalies early and late in the year (some setting new records) which were interspersed by near-average conditions for most of the austral autumn and winter. Here, we investigate the ocean-ice-atmosphere system off East Antarctica, prior to and during the Sea Ice Physics and Ecosystems eXperiment [SIPEX] 2012, by exploring relationships between atmospheric and oceanic forcing together with the sea-ice and snow characteristics. During August and September 2012, just prior to SIPEX 2012, atmospheric circulation over the Southern Ocean was near-average, setting up the ocean-ice-atmosphere system for near-average conditions. However, below-average surface pressure and temperature as well as strengthened circumpolar winds prevailed during June and July 2012. This led to a new record (19.4810 6 km 2 ) in maximum Antarctic sea-ice extent recorded in late September. In contrast to the weak circum-Antarctic conditions, the East Antarctic sector (including the SIPEX 2012 region) experienced positive sea-ice extent and concentration anomalies during most of 2012, coincident with negative atmospheric pressure and sea-surface temperature anomalies. Heavily deformed sea ice appeared to be associated with intensified wind stress due to increased cyclonicity as well as an increased influx of sea ice from the east. This increased westward ice flux is likely linked to the break-up of nearly 80% of the Mertz Glacier Tongue in 2010, which strongly modified the coastal configuration and hence the width of the westward coastal current. Combined with favourable atmospheric conditions the associated changed coastal configuration allowed more sea ice to remain within the coastal current at the expense of a reduced northward flow in the region around 141145E. In addition a westward propagating positive anomaly of sea-ice extent from the western Ross Sea during austral winter 2012 has been identified to have fed into the westward current of the SIPEX 2012 region. A pair of large grounded icebergs appears to have modified the local stress state as well as the structure of the ice pack upstream and also towards the Dalton Glacier Tongue. Together with the increased influx of sea ice into the regions, this contributed to the difficulties in navigating the SIPEX 2012 region. |
format |
Article in Journal/Newspaper |
author |
Heil, P Stammerjohn, S Reid, P Massom, RA Hutchings, JK |
author_facet |
Heil, P Stammerjohn, S Reid, P Massom, RA Hutchings, JK |
author_sort |
Heil, P |
title |
SIPEX 2012: extreme sea-ice and atmospheric conditions off East Antarctica |
title_short |
SIPEX 2012: extreme sea-ice and atmospheric conditions off East Antarctica |
title_full |
SIPEX 2012: extreme sea-ice and atmospheric conditions off East Antarctica |
title_fullStr |
SIPEX 2012: extreme sea-ice and atmospheric conditions off East Antarctica |
title_full_unstemmed |
SIPEX 2012: extreme sea-ice and atmospheric conditions off East Antarctica |
title_sort |
sipex 2012: extreme sea-ice and atmospheric conditions off east antarctica |
publisher |
Pergamon-Elsevier Science Ltd |
publishDate |
2016 |
url |
https://doi.org/10.1016/j.dsr2.2016.06.015 http://ecite.utas.edu.au/113764 |
long_lat |
ENVELOPE(-152.417,-152.417,-77.550,-77.550) ENVELOPE(144.500,144.500,-67.667,-67.667) ENVELOPE(145.500,145.500,-67.167,-67.167) |
geographic |
Antarctic Austral Dalton Glacier East Antarctica Mertz Glacier Mertz Glacier Tongue Ross Sea Southern Ocean |
geographic_facet |
Antarctic Austral Dalton Glacier East Antarctica Mertz Glacier Mertz Glacier Tongue Ross Sea Southern Ocean |
genre |
Antarc* Antarctic Antarctica East Antarctica ice pack Iceberg* Mertz Glacier Ross Sea Sea ice Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica ice pack Iceberg* Mertz Glacier Ross Sea Sea ice Southern Ocean |
op_relation |
http://dx.doi.org/10.1016/j.dsr2.2016.06.015 Heil, P and Stammerjohn, S and Reid, P and Massom, RA and Hutchings, JK, SIPEX 2012: extreme sea-ice and atmospheric conditions off East Antarctica, Deep-Sea Research II, 131 pp. 7-21. ISSN 0967-0645 (2016) [Refereed Article] http://ecite.utas.edu.au/113764 |
op_doi |
https://doi.org/10.1016/j.dsr2.2016.06.015 |
container_title |
Deep Sea Research Part II: Topical Studies in Oceanography |
container_volume |
131 |
container_start_page |
7 |
op_container_end_page |
21 |
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1766250683663646720 |