Southwest Pacific Benthic Foraminiferal B/Ca during the past 25 ka Allen, K.A.; Sikes, E.L.; Hönisch, B.; Elmore, A.C.; Guilderson, T.P.; Rosenthal, Y.; Anderson, R.F. Allen, K.A. Sikes, E.L. Hönisch, B. Elmore, A.C. Guilderson, T.P. Rosenthal, Y. Anderson, R.F. earth science/paleoclimate/paleocean (RR0503 83TC/JPC>LATITUDE -36.7375>LONGITUDE 176.6398) A greater amount of CO2 was stored in the deep sea during glacial periods, likely via greater efficiency of the biologic pump and increased uptake by a more alkaline ocean. Reconstructing past variations in seawater carbonate ion concentration (a major component of alkalinity) enables quantification of the relative roles of different oceanic CO2 storage mechanisms and also places constraints on the timing, magnitude, and location of subsequent deep ocean ventilation. Here, we present a record of deep-water inorganic carbon chemistry since the Last Glacial Maximum (LGM; ~19-23 ka BP), derived from sediment core RR0503-83 raised from 1627 m in New Zealand's Bay of Plenty. The core site lies within the upper limit of southern-sourced Circumpolar Deep Water (CDW), just below the lower boundary of Antarctic Intermediate Water (AAIW). We reconstruct past changes in bottom water inorganic carbon chemistry from the trace element and stable isotopic composition of calcite shells of the epibenthic foraminifer Cibicidoides wuellerstorfi. A record of ?CO32-(?CO32- = [COCO32-] in situ - [CO32-] saturation) derived from the foraminiferal boron to calcium ratio (B/Ca) provides evidence for greater ice-age storage of respired CO2 and reveals abrupt deglacial shifts in [CO32-] in situ of up to 30 μmol/kg (5 times larger than the difference between average LGM and Holocene values). The rapidity of these changes suggests the influence of changing water mass structure and atmospheric circulation in addition to a decrease in CO2 content of interior waters. STUDY NOTES: B/Ca of Cibicidoides wuellerstorfi (sometimes called Planulina wuellerstorfi) from RR0503-83 NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Allen, K.A. Investigator : Sikes, E.L. Investigator : Hönisch, B. Investigator : Elmore, A.C. Investigator : Guilderson, T.P. Investigator : Rosenthal, Y. Investigator : Anderson, R.F. 2019-05-01 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/26692 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/allen2015/allen2015-rr0503-83.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/allen2015/allen2015-rr0503-83.txt English https://www.ncdc.noaa.gov/paleo/study/26692 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/allen2015/allen2015-rr0503-83.txt Allen, Katherine A., Sikes, Elisabeth L., Hönisch, Bärbel, Elmore, Aurora C., Guilderson, Thomas P., Rosenthal, Yair, and Anderson, Robert F.2015Southwest Pacific deep water carbonate chemistry linked to high southern latitude climate and atmospheric CO2 during the Last Glacial TerminationQuaternary Science Reviews122180-19110.1016/j.quascirev.2015.05.007 START YEAR: 27200 cal yr BP * END YEAR: 1400 cal yr BP 176.6398 -36.7375 176.6398 -36.7375