Diatom-bound nitrogen isotope and TEX86L-SST records of MD12-3394 and MD11-3353 ...

• Main Authors: Ai, Xuyuan, Studer, Anja S, Sigman, Daniel M, Martínez-García, Alfredo, François, Fripiat, Thöle, Lena M, Michel, Elisabeth, Gottschalk, Julia, Arnold, Laura, Moretti, Simone, Schmitt, Mareike, Oleynik, Sergey, Jaccard, Samuel L, Haug, Gerald H
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2021
• Subjects: Diatom; nitrogen isotope; Southern Ocean; TEX86; Antarctic; Antarctic Ocean; Indian; The Antarctic; Antarc*; Neogloboquadrina pachyderma; Planktonic foraminifera
• Online Access: https://dx.doi.org/10.1594/pangaea.931028; https://doi.pangaea.de/10.1594/PANGAEA.931028

Previous studies suggest that, during the late Pleistocene ice ages, surface-deep exchange was somehow weakened in the Southern Ocean's Antarctic Zone (AZ), reducing the leakage of deeply sequestered CO2 and thus contributing to the lower atmospheric CO2 levels of the ice ages. To better understand the surface nutrient consumption in the Antarctic ocean during glacial intervals and its implication on atmospheric CO2 changes, we measured diatom-bound nitrogen isotopes (d15N_db) extending back to 150 thousand years ago (150ka) in two sediment cores in the Indian sector of the AZ. The data series include d15N_db, TEX86L-based SST, d18O of planktonic foraminifera Neogloboquadrina pachyderma (sin.), sediment Ba/Fe and the age model of MD12-3394 (48°23' S, 64°35' E, 2320m water depth), d15N_db and updated age model of MD11-3353 (50°34' S, 68°23' E, 1568m water depth), as well as the mean d15N_db of the two sediment cores, and the d15N_db offset calculated using the mean d15N_db and MD12-3394 d15N_db alone. The age ...