An ice-core proxy for northerly air mass incursions into West Antarctica

A 200-year proxy for northerly air mass incursions (NAMI) into central and western West Antarctica is developed from the examination of 19 shallow (21-150 m deep) Antarctic ice-core non-sea-salt (nss) Ca 2+ concentration records. The NAMI proxy reveals a significant rise in recent decades. This rise...

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Bibliographic Details
Published in:International Journal of Climatology
Main Authors: Dixon, Daniel A., Mayewski, Paul A., Goodwin, Ian D., Marshall, Gareth J., Freeman, Rhaelene, Maasch, Kirk A., Sneed, Sharon B.
Format: Article in Journal/Newspaper
Language:English
Published: 2012
Subjects:
Antarctic
glaciochemistry
Southern Hemisphere westerlies
climate change
International Trans Antarctic Scientific Expedition
atmospheric circulation
West Antarctica
Antarc*
Antarctica
ice core
Online Access:https://researchers.mq.edu.au/en/publications/5a5eed0d-3299-437f-9ccc-31f8dc795e70
https://doi.org/10.1002/joc.2371
http://www.scopus.com/inward/record.url?scp=84864139932&partnerID=8YFLogxK
Description
Summary:A 200-year proxy for northerly air mass incursions (NAMI) into central and western West Antarctica is developed from the examination of 19 shallow (21-150 m deep) Antarctic ice-core non-sea-salt (nss) Ca 2+ concentration records. The NAMI proxy reveals a significant rise in recent decades. This rise is unprecedented for at least the past 200 years and is coincident with anthropogenically driven changes in other large-scale Southern Hemisphere (SH) environmental phenomena such as greenhouse gas (GHG) induced warming, ozone depletion, and the associated intensification of the SH westerlies. The Hysplit trajectory model is used to examine air mass transport pathways into West Antarctica. Empirical orthogonal function analysis, in combination with trajectory results, suggests that atmospheric circulation is the dominant factor affecting nssCa 2+ concentrations throughout central and western West Antarctica. Ozone recovery will likely weaken the spring-summer SH westerlies in the future. Consequently, Antarctica could lose one of its best defences against SH GHG warming.

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