Centennial-scale trends in the Southern Annular Mode revealed by hemisphere-wide fire and hydroclimatic trends over the past 2400 years
Millennial-scale latitudinal shifts in the southern westerly winds (SWW) drive changes in Southern Ocean upwelling, leading to changes in atmospheric CO2 levels, thereby affecting the global climate and carbon cycle. Our aim here is to understand whether century-scale shifts in the SWW also drive ch...
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Geological Society of America
2018
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Online Access: | https://boris.unibe.ch/116490/6/363.pdf https://boris.unibe.ch/116490/ https://pubs.geoscienceworld.org/gsa/geology/article/46/4/363/528308/centennial-scale-trends-in-the-southern-annular |
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ftunivbern:oai:boris.unibe.ch:116490 2023-08-20T04:00:44+02:00 Centennial-scale trends in the Southern Annular Mode revealed by hemisphere-wide fire and hydroclimatic trends over the past 2400 years Fletcher, Michael-Shawn Benson, Alexa Bowman, David M.J.S. Gadd, Patricia S. Heijnis, Hendrik Mariani, Michela Saunders, Krystyna Wolfe, Brent B. Zawadzki, Atun 2018 application/pdf https://boris.unibe.ch/116490/6/363.pdf https://boris.unibe.ch/116490/ https://pubs.geoscienceworld.org/gsa/geology/article/46/4/363/528308/centennial-scale-trends-in-the-southern-annular eng eng Geological Society of America https://boris.unibe.ch/116490/ info:eu-repo/semantics/restrictedAccess Fletcher, Michael-Shawn; Benson, Alexa; Bowman, David M.J.S.; Gadd, Patricia S.; Heijnis, Hendrik; Mariani, Michela; Saunders, Krystyna; Wolfe, Brent B.; Zawadzki, Atun (2018). Centennial-scale trends in the Southern Annular Mode revealed by hemisphere-wide fire and hydroclimatic trends over the past 2400 years. Geology, 46(4), pp. 363-366. Geological Society of America 10.1130/G39661.1 <http://dx.doi.org/10.1130/G39661.1> 910 Geography & travel info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion PeerReviewed 2018 ftunivbern https://doi.org/10.1130/G39661.1 2023-07-31T21:44:17Z Millennial-scale latitudinal shifts in the southern westerly winds (SWW) drive changes in Southern Ocean upwelling, leading to changes in atmospheric CO2 levels, thereby affecting the global climate and carbon cycle. Our aim here is to understand whether century-scale shifts in the SWW also drive changes in atmospheric CO2 content. We report new multiproxy lake sediment data from southwest Tasmania, Australia, that show centennial-scale changes in vegetation and fire activity over the past 2400 yr. We compare our results with existing data from southern South America and reveal synchronous and in-phase centennial-scale trends in vegetation and fire activity between southwest Tasmania and southern South America over the past 2400 yr. Interannual to centennial-scale rainfall anomalies and fire activity in both these regions are significantly correlated with shifts in the SWW associated with the Southern Annular Mode (SAM; atmospheric variability of the Southern Hemisphere). Thus, we interpret the centennial-scale trends we have identified as reflecting century-scale SAM-like shifts in the SWW over the past 2400 yr. We identify covariance between our inferred century-scale shifts in the SWW and Antarctic ice core CO2 values, demonstrating that the SWW-CO2 relationship operating at a millennial scale also operates at a centennial scale through the past 2400 yr. Our results indicate a possible westerly-driven modulation of recent increases in global atmospheric CO2 content that could potentially exacerbate current greenhouse gas–related warming. Article in Journal/Newspaper Antarc* Antarctic ice core Southern Ocean BORIS (Bern Open Repository and Information System, University of Bern) Antarctic Southern Ocean Geology 46 4 363 366 |
institution |
Open Polar |
collection |
BORIS (Bern Open Repository and Information System, University of Bern) |
op_collection_id |
ftunivbern |
language |
English |
topic |
910 Geography & travel |
spellingShingle |
910 Geography & travel Fletcher, Michael-Shawn Benson, Alexa Bowman, David M.J.S. Gadd, Patricia S. Heijnis, Hendrik Mariani, Michela Saunders, Krystyna Wolfe, Brent B. Zawadzki, Atun Centennial-scale trends in the Southern Annular Mode revealed by hemisphere-wide fire and hydroclimatic trends over the past 2400 years |
topic_facet |
910 Geography & travel |
description |
Millennial-scale latitudinal shifts in the southern westerly winds (SWW) drive changes in Southern Ocean upwelling, leading to changes in atmospheric CO2 levels, thereby affecting the global climate and carbon cycle. Our aim here is to understand whether century-scale shifts in the SWW also drive changes in atmospheric CO2 content. We report new multiproxy lake sediment data from southwest Tasmania, Australia, that show centennial-scale changes in vegetation and fire activity over the past 2400 yr. We compare our results with existing data from southern South America and reveal synchronous and in-phase centennial-scale trends in vegetation and fire activity between southwest Tasmania and southern South America over the past 2400 yr. Interannual to centennial-scale rainfall anomalies and fire activity in both these regions are significantly correlated with shifts in the SWW associated with the Southern Annular Mode (SAM; atmospheric variability of the Southern Hemisphere). Thus, we interpret the centennial-scale trends we have identified as reflecting century-scale SAM-like shifts in the SWW over the past 2400 yr. We identify covariance between our inferred century-scale shifts in the SWW and Antarctic ice core CO2 values, demonstrating that the SWW-CO2 relationship operating at a millennial scale also operates at a centennial scale through the past 2400 yr. Our results indicate a possible westerly-driven modulation of recent increases in global atmospheric CO2 content that could potentially exacerbate current greenhouse gas–related warming. |
format |
Article in Journal/Newspaper |
author |
Fletcher, Michael-Shawn Benson, Alexa Bowman, David M.J.S. Gadd, Patricia S. Heijnis, Hendrik Mariani, Michela Saunders, Krystyna Wolfe, Brent B. Zawadzki, Atun |
author_facet |
Fletcher, Michael-Shawn Benson, Alexa Bowman, David M.J.S. Gadd, Patricia S. Heijnis, Hendrik Mariani, Michela Saunders, Krystyna Wolfe, Brent B. Zawadzki, Atun |
author_sort |
Fletcher, Michael-Shawn |
title |
Centennial-scale trends in the Southern Annular Mode revealed by hemisphere-wide fire and hydroclimatic trends over the past 2400 years |
title_short |
Centennial-scale trends in the Southern Annular Mode revealed by hemisphere-wide fire and hydroclimatic trends over the past 2400 years |
title_full |
Centennial-scale trends in the Southern Annular Mode revealed by hemisphere-wide fire and hydroclimatic trends over the past 2400 years |
title_fullStr |
Centennial-scale trends in the Southern Annular Mode revealed by hemisphere-wide fire and hydroclimatic trends over the past 2400 years |
title_full_unstemmed |
Centennial-scale trends in the Southern Annular Mode revealed by hemisphere-wide fire and hydroclimatic trends over the past 2400 years |
title_sort |
centennial-scale trends in the southern annular mode revealed by hemisphere-wide fire and hydroclimatic trends over the past 2400 years |
publisher |
Geological Society of America |
publishDate |
2018 |
url |
https://boris.unibe.ch/116490/6/363.pdf https://boris.unibe.ch/116490/ https://pubs.geoscienceworld.org/gsa/geology/article/46/4/363/528308/centennial-scale-trends-in-the-southern-annular |
geographic |
Antarctic Southern Ocean |
geographic_facet |
Antarctic Southern Ocean |
genre |
Antarc* Antarctic ice core Southern Ocean |
genre_facet |
Antarc* Antarctic ice core Southern Ocean |
op_source |
Fletcher, Michael-Shawn; Benson, Alexa; Bowman, David M.J.S.; Gadd, Patricia S.; Heijnis, Hendrik; Mariani, Michela; Saunders, Krystyna; Wolfe, Brent B.; Zawadzki, Atun (2018). Centennial-scale trends in the Southern Annular Mode revealed by hemisphere-wide fire and hydroclimatic trends over the past 2400 years. Geology, 46(4), pp. 363-366. Geological Society of America 10.1130/G39661.1 <http://dx.doi.org/10.1130/G39661.1> |
op_relation |
https://boris.unibe.ch/116490/ |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1130/G39661.1 |
container_title |
Geology |
container_volume |
46 |
container_issue |
4 |
container_start_page |
363 |
op_container_end_page |
366 |
_version_ |
1774719986931073024 |