Stable isotope records and biogenic barium fluxes of sediment core SO202-07-06 ...

• Main Authors: Ren, Haojia Abby, Studer, Anja S, Serno, Sascha, Sigman, Daniel M, Winckler, Gisela, Anderson, Robert F, Oleynik, Sergey, Gersonde, Rainer, Haug, Gerald H
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2015
• Subjects: Neogloboquadrina pachyderma; Subarctic; ren
• Online Access: https://dx.doi.org/10.1594/pangaea.854813; https://doi.pangaea.de/10.1594/PANGAEA.854813

Reduced nitrate supply to the subarctic North Pacific (SNP) surface during the last ice age has been inferred from coupled changes in diatom-bound d15N (DB-d15N), bulk sedimentary d15N, and biogenic fluxes. However, the reliability of bulk sedimentary and DB-d15N has been questioned, and a previously reported d15N minimum during Heinrich Stadial 1 (HS1) has proven difficult to explain. In a core from the western SNP, we report the foraminifera-bound d15N (FB-d15N) in Neogloboquadrina pachyderma and Globigerina bulloides, comparing them with DB-d15N in the same core over the past 25 kyr. The d15N of all recorders is higher during the Last Glacial Maximum (LGM) than in the Holocene, indicating more complete nitrate consumption. N. pachyderma FB-d15N is similar to DB-d15N in the Holocene but 2.2 per mil higher during the LGM. This difference suggests a greater sensitivity of FB-d15N to changes in summertime nitrate drawdown and d15N rise, consistent with a lag of the foraminifera relative to diatoms in reaching ... : Supplement to: Ren, Haojia Abby; Studer, Anja S; Serno, Sascha; Sigman, Daniel M; Winckler, Gisela; Anderson, Robert F; Oleynik, Sergey; Gersonde, Rainer; Haug, Gerald H (2015): Glacial-to-interglacial changes in nitrate supply and consumption in the subarctic North Pacific from microfossil-bound N isotopes at two trophic levels. Paleoceanography, 30(9), 1217-1232 ...