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Diatom stable isotopes, sea ice presence and sea surface temperature records of the past 640 ka in the Atlantic sector of the Southern Ocean
Author(s) -
SchneiderMor Aya,
Yam Ruth,
Bianchi Cristina,
KunzPirrung Martina,
Gersonde Rainer,
Shemesh Aldo
Publication year - 2005
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2005gl022543
Subject(s) - oceanography , polar front , interglacial , geology , diatom , sea ice , ice core , glacial period , sea surface temperature , water column , δ18o , climatology , stable isotope ratio , paleontology , physics , quantum mechanics
High‐resolution δ 13 C and δ 15 N records of diatom‐bound organic matter (δ 13 C D , δ 15 N D ) from ODP site 1094, South of the Polar Front, are combined with reconstructions of summer sea surface temperature and winter sea‐ice to establish changes in surface water characteristics associated with the main climatic events of the past 640 ka. The six glacial‐interglacial δ 13 C D cycles show excellent agreement with SPECMAP δ 18 O and Vostok CO 2 content, suggesting that global physical processes rather than local biological factors were the main influences on δ 13 C D . By contrast, there is weak correspondence between the Vostok dust record and the δ 13 C D and δ 15 N D records. The data do not support the hypothesis that glacial iron fertilization of the Southern Ocean was the main factor lowering atmospheric CO 2 , if dust accumulation represents iron input. The records indicate that sea ice cover, water column stratification and iron addition from deep water mixing are more likely to explain our observations.