Precipitation variability in the winter rainfall zone of South Africa during the last 1400 yr linked to the austral westerlies
The austral westerlies strongly influence precipitation and ocean circulation in the southern temperate zone, with important consequences for cultures and ecosystems. Global climate models anticipate poleward retreat of the austral westerlies with future warming, but the available paleoclimate recor...
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fttriple:oai:gotriple.eu:10670/1.u6n928 2023-05-15T13:55:12+02:00 Precipitation variability in the winter rainfall zone of South Africa during the last 1400 yr linked to the austral westerlies Stager, J. C. Mayewski, P. A. White, J. Chase, B. M. Neumann, F. H. Meadows, M. E. King, C. D. Dixon, D. A. 2018-09-27 https://doi.org/10.5194/cp-8-877-2012 https://cp.copernicus.org/articles/8/877/2012/ en eng doi:10.5194/cp-8-877-2012 10670/1.u6n928 https://cp.copernicus.org/articles/8/877/2012/ undefined Geographica Helvetica - geography eISSN: 1814-9332 geo envir Text https://vocabularies.coar-repositories.org/resource_types/c_18cf/ 2018 fttriple https://doi.org/10.5194/cp-8-877-2012 2023-01-22T17:32:51Z The austral westerlies strongly influence precipitation and ocean circulation in the southern temperate zone, with important consequences for cultures and ecosystems. Global climate models anticipate poleward retreat of the austral westerlies with future warming, but the available paleoclimate records that might test these models have been limited to South America and New Zealand, are not fully consistent with each other and may be complicated by influences from other climatic factors. Here we present the first high-resolution diatom and sedimentological records from the winter rainfall region of South Africa, representing precipitation in the equatorward margin of the westerly wind belt during the last 1400 yr. Inferred rainfall was relatively high ∼1400–1200 cal yr BP, decreased until ∼950 cal yr BP, and rose notably through the Little Ice Age with pulses centred on ∼600, 530, 470, 330, 200, 90, and 20 cal yr BP. Synchronous fluctuations in Antarctic ice core chemistry strongly suggest that these variations were linked to changes in the westerlies. Equatorward drift of the westerlies during the wet periods may have influenced Atlantic meridional overturning circulation by restricting marine flow around the tip of Africa. Apparent inconsistencies among some aspects of records from South America, New Zealand and South Africa warn against the simplistic application of single records to the Southern Hemisphere as a whole. Nonetheless, these findings in general do support model projections of increasing aridity in the austral winter rainfall zones with future warming. Text Antarc* Antarctic ice core Unknown Antarctic Austral New Zealand Climate of the Past 8 3 877 887 |
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geo envir Stager, J. C. Mayewski, P. A. White, J. Chase, B. M. Neumann, F. H. Meadows, M. E. King, C. D. Dixon, D. A. Precipitation variability in the winter rainfall zone of South Africa during the last 1400 yr linked to the austral westerlies |
topic_facet |
geo envir |
description |
The austral westerlies strongly influence precipitation and ocean circulation in the southern temperate zone, with important consequences for cultures and ecosystems. Global climate models anticipate poleward retreat of the austral westerlies with future warming, but the available paleoclimate records that might test these models have been limited to South America and New Zealand, are not fully consistent with each other and may be complicated by influences from other climatic factors. Here we present the first high-resolution diatom and sedimentological records from the winter rainfall region of South Africa, representing precipitation in the equatorward margin of the westerly wind belt during the last 1400 yr. Inferred rainfall was relatively high ∼1400–1200 cal yr BP, decreased until ∼950 cal yr BP, and rose notably through the Little Ice Age with pulses centred on ∼600, 530, 470, 330, 200, 90, and 20 cal yr BP. Synchronous fluctuations in Antarctic ice core chemistry strongly suggest that these variations were linked to changes in the westerlies. Equatorward drift of the westerlies during the wet periods may have influenced Atlantic meridional overturning circulation by restricting marine flow around the tip of Africa. Apparent inconsistencies among some aspects of records from South America, New Zealand and South Africa warn against the simplistic application of single records to the Southern Hemisphere as a whole. Nonetheless, these findings in general do support model projections of increasing aridity in the austral winter rainfall zones with future warming. |
format |
Text |
author |
Stager, J. C. Mayewski, P. A. White, J. Chase, B. M. Neumann, F. H. Meadows, M. E. King, C. D. Dixon, D. A. |
author_facet |
Stager, J. C. Mayewski, P. A. White, J. Chase, B. M. Neumann, F. H. Meadows, M. E. King, C. D. Dixon, D. A. |
author_sort |
Stager, J. C. |
title |
Precipitation variability in the winter rainfall zone of South Africa during the last 1400 yr linked to the austral westerlies |
title_short |
Precipitation variability in the winter rainfall zone of South Africa during the last 1400 yr linked to the austral westerlies |
title_full |
Precipitation variability in the winter rainfall zone of South Africa during the last 1400 yr linked to the austral westerlies |
title_fullStr |
Precipitation variability in the winter rainfall zone of South Africa during the last 1400 yr linked to the austral westerlies |
title_full_unstemmed |
Precipitation variability in the winter rainfall zone of South Africa during the last 1400 yr linked to the austral westerlies |
title_sort |
precipitation variability in the winter rainfall zone of south africa during the last 1400 yr linked to the austral westerlies |
publishDate |
2018 |
url |
https://doi.org/10.5194/cp-8-877-2012 https://cp.copernicus.org/articles/8/877/2012/ |
geographic |
Antarctic Austral New Zealand |
geographic_facet |
Antarctic Austral New Zealand |
genre |
Antarc* Antarctic ice core |
genre_facet |
Antarc* Antarctic ice core |
op_source |
Geographica Helvetica - geography eISSN: 1814-9332 |
op_relation |
doi:10.5194/cp-8-877-2012 10670/1.u6n928 https://cp.copernicus.org/articles/8/877/2012/ |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/cp-8-877-2012 |
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Climate of the Past |
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8 |
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3 |
container_start_page |
877 |
op_container_end_page |
887 |
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