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VER tical T ransport I n the G lobal O cean VERTIGO. What controls the efficiency of particle transport between the surface and deep ocean? Geochemistry (particle characteristics), Biology (euphotic zone and mesopelagic bacteria/plankton) Physics (particle source region). Cruises- - PowerPoint PPT Presentation
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VERtical Transport In the Global OceanVERTIGO
http://cafethorium.whoi.edu VERTIGO project web site
• What controls the efficiency of particle transport between the surface and deep ocean?
Geochemistry (particle characteristics),Biology (euphotic zone and mesopelagic bacteria/plankton)Physics (particle source region)
Cruises-Jan & June 2004- Hawaii HOT station ALOHA w/RV Kilo MoanaJuly 2005- Station “K2” 47N 160E with RV Revelle
VERTIGO PI’s & InstitutionKen Buesseler, Woods Hole Oceanographic Jim Bishop, Lawrence Berkeley National Phil Boyd, National Institute of Water and Atmospheric Res., NZ Karen Casciotti, Woods Hole Oceanographic Carl Lamborg, Woods Hole Oceanographic Institution Dave Siegel, University of California, Santa Barbara Mary Silver, University of California, Santa Cruz Debbie Steinberg, Virginia Institute of Marine Tom Trull, University of Tasmania, Australia Jim Valdes, Woods Hole Oceanographic Institution Ben Van Mooy, Woods Hole Oceanographic Frank Dehairs, University of Brussels, Belgium
Collaborators Claudia Benitez-Nelson, University of South Carolina Bob Bidigare, University of Hawaii M. Sarin, Physical Research Laboratory, IndiaSei-ichi Saito, Hokkaido Univ., JapanNianghi “George” Jiao, Xiamen Univ., ChinaToru Kobari, Kagoshima Univ., Japan
NBST – Neutrally Buoyant Sediment Trap
Free vehicleActive buoyancy control<1 day to multi day missionReturn to surface closed GPS & flasher
VERTIGO traps 10 in water! n=4 @150, 3@ 300, 3@ 500mboth HgCl2 poisons & formalin (& blanks); 2 deployments
“Splitter”wet split at sea with clean methods
Analyses include-mass, C, N, P, PIC, bSiICPMS- Fe, Ca, Al, Mn, Ti…….234Th, 210Pb, 210PoChlorophyll pigmentsstable 13C & 15NDNAMicroscope- ID, pellets, stainsFrozen- organic biomarkers?
Swimmer removal-screens & picking
Separate experiments-“gel” trapsAging expt.
VERTIGO Site Surveys- sensors & geochemistry/biology
What a trap samples…Origins
Collections
Siegel et al.
250m
surface
trap path @500m
Deployment 1
Blank Corrected Mass Flux (mg/m2/d)
0 20 40 60 80 100 120
Dep
th (
m)
0
100
200
300
400
500
600
NBSTCLAP
Martin Curves (Fz=F100*(z/100)-b)
System F100 b F100 S.D. b S.D.NBST_Dep. 1 92.55 -1.0720 ±8.60 ±0.1331NBST_Dep. 2 88.33 -1.0040 ±6.46 ±0.1138CLAP_Dep. 1 101.00 -0.8400 ±6.20 ±0.0660CLAP_Dep. 2 87.54 -0.7166 ±6.16 ±0.0846
NBST
CLAP
Subtle differences between trapsNBST remineralization “b” >drifting CLAP trap
PN Flux (mg m-2 d-1)
0 1 2 3 4 5 6 7
PO
C F
lux
(mg
m-2
d-1
)
0
10
20
30
PC=PN x (6.4±0.3) - (3.7±0.5) mass/massPC=PN x (7.5±0.4) - (4.4±0.6) mole/moler2=0.95
redfield ratio
max C/N = 35
- natural variability in flux vs. depth is common in all flux data
- but less difference in relative
compositions: element to element ratios
see preferentialremineralizationof N over C- follows Redfieldw/residual low C/Nmaterial intact
Fe 2nd Trap Deployment
Flux (µg m-2 d-1)
0 100 200 300 400 500 600
De
pth
(m
)
0
100
200
300
400
500
600
Iron shows less attenuation vs. depth than C
C/Fe ratio decreases with depth
NBST
CLAP
Ca/Al
1 day
3 days
5 days
1 day
3 days
5 days
1 day
3 days
5 days
1 day
3 days
5 days
1 day
3 days
5 days
1 day
3 days
5 days
mas
s ra
tio
0
10
20
30
40
50
150m
300m
500m
1st Dep. - Hg 2nd Dep. - Formalin
Fe/Al
1 day
3 days
5 days
1 day
3 days
5 days
1 day
3 days
5 days
1 day
3 days
5 days
1 day
3 days
5 days
1 day
3 days
5 days
mas
s ra
tio
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
150m
300m 500m
1st Dep. - Hg 2nd Dep. - Formalin
P/Al
1 day
3 days
5 days
1 day
3 days
5 days
1 day
3 days
5 days
1 day
3 days
5 days
1 day
3 days
5 days
1 day
3 days
5 days
mas
s ra
tio
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
150m
300m
500m
1st Dep. - Hg 2nd Dep. - Formalin
DOC in overlying brine
1 day
3 days
5 days
1 day
3 days
5 days
1 day
3 days
5 days
1 day
3 days
5 days
1 day
3 days
5 days
1 day
3 days
5 days
DO
C (
µM
)
0
50
100
150
200
150m
300m
500m
1st Dep. - Hg 2nd Dep. - Formalin
Incubations of Poisoned Trap Material (and DOC from brine)
Incubation shows scant evidence for systematic loss of particulate material, or in the case of C, appearance in the overlying brine (small impact on P)
Short-deployment trap experiments are not likely subject to diagenetic artifacts.
1,3,5days
P/Al
T0
150
T1
150
T2
150
T3
150
T5
150
T0
300
T1
300
T2
300
T3
300
T5
300
T0
500
T1
500
T2
500
T3
500
T5
500
ratio
0.0
0.2
0.4
0.6
0.8
1.0
Ca/Al
T0
150
T1
150
T2
150
T3
150
T5
150
T0
300
T1
300
T2
300
T3
300
T5
300
T0
500
T1
500
T2
500
T3
500
T5
500
ratio
0
5
10
15
20
25
Sr/Al
T0
15
0
T1
15
0
T2
15
0
T3
15
0
T5
15
0
T0
30
0
T1
30
0
T2
30
0
T3
30
0
T5
30
0
T0
50
0
T1
50
0
T2
50
0
T3
50
0
T5
50
0
ratio
0.0
0.2
0.4
0.6
0.8
Incubations of Unpoisoned Large Particles from MULVFS Screens
These unpoisoned samples do show evidence of loss of material from particle phase, esp. at the shallowest depth (compare to in situ changes vs. depth)
Ba/Al
T0
150
T1
150
T2
150
T3
150
T5
150
T0
300
T1
300
T2
300
T3
300
T5
300
T0
500
T1
500
T2
500
T3
500
T5
500
ratio
0.0
0.1
0.2
0.3
0.4
0,1,3,5 days
150m 300m 500m
Comparison of Unpoisoned Degradation Rate with Vertical Flux Attenuationto derive effective sinking rate
Element Vertical “Half-Distance”
Incubation “Half-Life”
Sinking Rate Needed to Match
P 150 m 3 days 50 m d-1
Ca 250 m 2 days 125 m d-1
Sr 65 m 2 days 33 m d-1
Ba large 1 day large
VERTIGOgear includes-
Trull
Boyd
Bishop
Steinberg/Silver
Trull
Pellet Shape - Carbon
0.00
0.50
1.00
1.50
2.00
2.50
3.00
3.50
4.00
4.50
5.00
amorphous cylindrical elliptical ovoid spherical
Car
bo
n (
ug
)
150m
300m
500m
Biological studies-zooplanktonSteinberg et al.
Bacterial production (mmol C m-3 d-1)
0.0001 0.001 0.01 0.1 1 10
Log 1
0 d
epth
(m
)
0
100
200
300
400
500
Cast 028, b(100-500m) = -2.998
Cast 084, b(100-500m) = -2.366
VERTIGO ALOHABacterial Production
- goal is to understand rates and controls of particle export and remineralization in the mesopelagic zone
0
20
40
60
80
100
120
140
0.0 1.0 2.0 3.0
N-uptake (pmol/l/h)
Dep
th (m
) ctd 19 - 23 June
ctd 27 - 25 June
ctd 33 - 27 June
ctd 45 - 29 June
ctd 79 - 3 July
ctd 83 - 5 July
ctd 95 - 7 July
ctd 99 - 9 July
average (w/o ctd 19)
bacteria- rates & IDVan Mooy, Casciotti et al.
phytoplankton- rates & IDDehairs, Silver, Boyd et al.
VERTIGO June 2004 Trap Deployment #1
Particulate Organic C / Inorganic C ratio
0 2 4 6 8 10
Dep
th (
m)
0
100
200
300
400
500
Preliminary PIC data (est. from Ca)
Changes in PIC:POC ratio impact strength of ocean C sink- ballast/PIC increases w/z- compare: ALOHA- Ca & coccolithophores
vs. NW Pacific K2- bSi & diatoms
VERTIGOwhat’s next-
- Summer 2005 VERTIGO cruise out of Japan- organize one day science workshop July 18- Yokohama
50% VERTIGO science presentations50% Japanese time-series/K2/particle science
- Japanese & Chinese scientists to join cruise (n=4)- July 21-Aug 28, RV Revelle, Yokohama to Honolulu
- Special mesoplelagic/particle flux sessionFeb. 2006 Ocean Sciences meeting, HonoluluJoint with Cindy Lee (MedFlux); Hiroaki Saito (DEEP) & Buesseler (VERTIGO) PI meeting 2.5 days- prior to Ocean Sciences mtg.
- VERTIGO II?
VERTIGO PI’s & InstitutionKen Buesseler, Woods Hole Oceanographic Jim Bishop, Lawrence Berkeley National Phil Boyd, National Institute of Water and Atmospheric Research Karen Casciotti, Woods Hole Oceanographic Carl Lamborg, Woods Hole Oceanographic Institution Dave Siegel, University of California, Santa Barbara Mary Silver, University of California, Santa Cruz Debbie Steinberg, Virginia Institute of Marine Tom Trull, University of Tasmania Jim Valdes, Woods Hole Oceanographic Institution Ben Van Mooy, Woods Hole Oceanographic
Collaborators Claudia Benitez-Nelson, University of South Carolina Bob Bidigare, University of Hawaii Frank Dehairs, University of BrusselsM. Sarin, Physical Research Laboratory S. Honjo & Japanese scientists? K2 site
Horizontal flow(hydrodynamics)
Shallow sediment traps
Preservation (solubilization in collection tubes)
Swimmers
- accuracy issues
Fe 2nd Deployment
Flux (µg m-2 d-1)
0 100 200 300 400 500 600
De
pth
(m
)0
100
200
300
400
500
600
VERTIGO Site Surveys- sensors & geochemistry/biology
An assessment of particulate organic carbon to thorium-234 ratios in the ocean and their impact on the application of 234Th as a POC flux proxy
K. O. Buesseler, C. R. Benitez-Nelson, S. B. Moran, A. Burd, M. Charette, J. K. Cochran, L. Coppola, N. S. Fisher, S. W. Fowler, W. D. Gardner, L. D. Guo, O.
Gustafsson, C. Lamborg, P. Masque, J. C. Miquel, U. Passow, P. H. Santschi, N. Savoye, G. Stewart, and T. Trull
Submitted March 2005
Marine Particles“separate biogeochemistry from physical
oceanography”
Marine Particles“separate biogeochemistry from physical
oceanography”
How do we get from here?
C uptake in surface ocean-SeaWiFS global primary productionBehrenfeld & Falkowski, 1997
To here?
C flux to seafloor -benthic O2 demandJahnke, 1996
Diatom assoc. fluxhigh “b”
Coccolithophoridassoc. POC flux
Why can’t diatoms control upper ocean export on regional or seasonal basis, while CaCO3 materials show stronger association with deep flux?Differences abound- in diatom types, sinking rates & bSi/C ratios
Carbon flux = 234Th flux [C/234Th]sinking particlesCarbon flux = 234Th flux [C/234Th]sinking particles
• Empirical approach• Highest in (diatom) blooms & coastal ocean• Must use site and depth appropriate ratio•Issues remain on how best to sample particles
