FN Archimer Export Format
PT J
TI Reconciling down core anticorrelation of diatom carbon and nitrogen isotopic ratios from the Southern Ocean
BT 
AF CROSTA, X
   SHEMESH, A
AS 1:1;2:1;
FF 1:;2:;
C1 Weizmann Inst Sci, Dept Environm Sci, Rehovot, Israel.
C2 WEIZMANN INST SCI, ISRAEL
IF 3.871
TC 117
UR https://archimer.ifremer.fr/doc/00223/33402/31859.pdf
LA English
DT Article
DE ;Southern Ocean;paleoceanography;geochemistry;diatoms
AB [1] Oceanic nutrient cycling in the Southern Ocean is supposed to have an important impact on glacial-interglacial atmospheric CO(2) 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 (delta(13)C(diat) and delta(15)N(diat)- respectively) in two cores retrieved form the Atlantic and Indian sectors of the Antarctic Ocean. The two cores show the same isotopic patterns. The delta(13)C(diat) values are depleted during glacial periods and enriched during interglacial periods, indicating lower productivity during cold times. The delta(15)N(diat) 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 CO, changes. However, the two sets of data can be reconciled by a "sea ice plus mixing rate scenario" that calls upon a balance between the effect Of Cutting off gas transfer at the ocean-atmosphere boundary and the effect of reducing vertical transport of nutrients through the pycnocline.
PY 2002
PD FEB
SO Paleoceanography
SN 0883-8305
PU Amer Geophysical Union
VL 17
IS 1
UT 000175990500010
DI 10.1029/2000PA000565
ID 33402
ER

EF