Silicic acid utilization efficiency
3
Silicic acid utilization efficiency • Paleo-proxy: Termination II, Southern Ocean • Large change in 30 Si across Termination 0.0 0.5 1.0 1.5 2.0 2.5 60 80 100 120 140 160 180 A ge (ka) 30 Si 0 1 2 3 4 5 6 7 8 15 N (inverted scale) d30S i co-m easured d15N 3 pointaverage d15N OIS 5e Termination II OIS 6
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Silicic acid utilization efficiency. Paleo-proxy: Termination II, Southern Ocean Large change in d 30 Si across Termination. OIS 6. OIS 5e. Termination II. Modeling oceanic d 30 Si. Seasonal fractionation Export of biogenic opal High utilization in gyres - PowerPoint PPT Presentation
Transcript of Silicic acid utilization efficiency
Silicic acid utilization efficiency
• Paleo-proxy: Termination II, Southern Ocean
• Large change in 30Si across Termination
0.0
0.5
1.0
1.5
2.0
2.5
60 80 100 120 140 160 180
Age (ka)
30S
i
0
1
2
3
4
5
6
7
8
15N
(in
ve
rte
d s
ca
le)
d30Si
co-measured d15N
3 point average d15N
OIS 5e
Termination II
OIS 6
Modeling oceanic 30Si• Seasonal fractionation• Export of biogenic opal• High utilization in gyres• But no deep-water
signals expected
Wis
chm
eyer
et
al. `
03
Global Deep-Water Distribution
• Strong [Si] and isotopic contrasts
0
500
1000
1500
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3500
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4500
0 0.5 1 1.5 2 2.5 330Si
De
pth
(m
)
Arctic
North Atlantic
South Atlantic
Southern Ocean (51 S)
North Pacific
0
500
1000
1500
2000
2500
3000
3500
4000
4500
0.0 50.0 100.0 150.0
Si concentration (microMolar)
Dep
th (m
)
ArcticNorth AtlanticSouth AtlanticSouthern Ocean (51 S)North Pacific
Along “conveyor”
