Verlorenvlei, South Africa 1400 Year Diatom Abundance Data Stager, J.C.; Mayewski, P.A.; White, J.; Chase, B.M.; Neumann, F.H.; Meadows, M.E.; King, C.D.; Dixon, D.A. Stager, J.C. Mayewski, P.A. White, J. Chase, B.M. Neumann, F.H. Meadows, M.E. King, C.D. Dixon, D.A. westerlies earth science/paleoclimate/paleolimnology (depth,null,null,centimeter,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (age,null,null,year Common Era,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (total epiphytic diatoms,null,null,percent,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (diatom tolerance-based index,null,null,percent,null,paleolimnology,null,null,N,diluted water taxa) earth science/paleoclimate/paleolimnology (diatom tolerance-based index,null,null,percent,null,paleolimnology,null,null,N,brackish water taxa) earth science/paleoclimate/paleolimnology (age,null,null,calendar year before present,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (Verlorenvlei>LATITUDE -32.36>LONGITUDE 18.44) 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. STUDY NOTES: Diatom time series from Verlorenvlei, South Africa for the past 1400 years. Diatom data grouped as follows: dilute-water taxa = mostly Aulacoseira granulata + Nitzschia lacuum + Synedra delicatissima (sensu Partrick & Reimer) Brackish taxa = Cyclotella meneghiniana + Thalassiosira Epiphytic taxa = Cocconeis + Epithemia Higher "% dilute" interpreted as indicating more winter rains, with austral westerlies shifted equatorward. Core VV09, Verlorenvlei, South Africa: 32.36°S, 18.44°'E, ~1m elevation, 4m water depth. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Stager, J.C. Investigator : Mayewski, P.A. Investigator : White, J. Investigator : Chase, B.M. Investigator : Neumann, F.H. Investigator : Meadows, M.E. Investigator : King, C.D. Investigator : Dixon, D.A. 2012-05-15 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/12910 https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/africa/verlorenvlei2012.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/africa/verlorenvlei2012.xls https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/africa/verlorenvlei2012.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/africa/verlorenvlei2012.xls English https://www.ncdc.noaa.gov/paleo/study/12910 https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/africa/verlorenvlei2012.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/africa/verlorenvlei2012.xls Stager, J.C., P.A. Mayewski, J. White, B.M. Chase, F.H. Neumann, M.E. Meadows, C.D. King, and D.A. Dixon. 2012. Precipitation variability in the winter rainfall zone of South Africa during the last 1400 yr linked to the austral westerlies. Climate of the Past, Vol. 8, pp. 877-887. www.clim-past.net/8/877/2012/ doi:10.5194/cp-8-877-2012 START YEAR: 1400 cal yr BP * END YEAR: -59 cal yr BP 18.44 -32.36 18.44 -32.36