Stable isotope composition of diatom-bound organic matter ...
Oceanic nutrient cycling in the Southern Ocean is supposed to have an important impact on glacial-interglacial atmospheric CO2 changes and global climate. In order to characterize such nutrient cycling over the last two climatic cycles we investigated carbon and nitrogen isotopic ratios of diatom-bo...
Main Authors: | , |
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Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
PANGAEA
2002
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Subjects: | |
Online Access: | https://dx.doi.org/10.1594/pangaea.846543 https://doi.pangaea.de/10.1594/PANGAEA.846543 |
Summary: | Oceanic nutrient cycling in the Southern Ocean is supposed to have an important impact on glacial-interglacial atmospheric CO2 changes and global climate. In order to characterize such nutrient cycling over the last two climatic cycles we investigated carbon and nitrogen isotopic ratios of diatom-bound organic matter (d13Cdiat and d15Ndiat, respectively) in two cores retrieved form the Atlantic and Indian sectors of the Antarctic Ocean. The two cores show the same isotopic patterns. The d13Cdiat values are depleted during glacial periods and enriched during interglacial periods, indicating lower productivity during cold times. The d15Ndiat values are enriched during glacial periods and depleted during interglacial periods, arguing for greater nitrate utilization during cold times. Taken at face value, this apparent contradiction leads to opposite conclusions on the role of the Southern Ocean biological pump on the atmospheric CO2 changes. However, the two sets of data can be reconciled by a "sea ice plus ... : Supplement to: Crosta, Xavier; Shemesh, Aldo (2002): Reconciling down core anticorrelation of diatom carbon and nitrogen isotopic ratios from the Southern Ocean. Paleoceanography, 17(1), 10-1-10-8 ... |
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