April 10 May 30

Ocean Fertilization by Gobi Dust Observed: First Deployment of Robotic Carbon Explorers

PAPAGobi Desert Dust Crosses Pacific April 10-14, 2001

Particulate Organic Carbon

Bishop, J.K.B., et al. (2002) Science 298, 817-821.

Ocean Fertilization by Gobi Dust Observed: First Deployment of Robotic Carbon Explorers

Bishop, J.K.B., et al. (2002) Science 298, 817-821.

Surface Biomass Doubled

0.35

0.45

0.55

Net POC Growth Rate and POC/Chl ratio Increased here

April 10 May 30UTC days (2001)

Similar favorable conditions, but little biomass increase

Satellite Chlorophyll Increased by just 20%

West to East Decrease in Aerosol => Dust Deposition

PAPAGobi Desert Dust Crosses Pacific April 10-14, 2001

417

“North Patch” (55 S) High NO3 : Low Si(22 M : 2.5 M)

SOFeX Hypothesis:

Silica Limitation ofDiatom productivity

means limited CarbonExport.

“South Patch” (66 S) High NO3: High Si

(27 M : 60 M)

Funding DOE Office of Science , NSF

SOFeX and Explorer Positions: Jan 10 - Mar 10 2002

Bishop et al. Science, 304, 417-420, 2004

“North Patch” (55 S) High NO3 : Low Si(22 M : 2.5 M)

First Controlled Long-term High Frequency Observations of the effects of purposful iron additions to the ocean.

Measuered Enhanced Carbon Export at 55S

Fe added : C Exported mole ratio >1:104

SOFeX Hypothesis Contradicted

Export surprisingly strong N of the Polar Front

– Cost Effective Carbon Monitoring Possible

MLD 0.05

0.5

1

2

4

8

CARBON FLUX INDEX in RED

POCM)

Bishop et al. Science, 304, 417-420, 2004

Background/information slides

Gobi Desert Dust Crosses Pacific April 10-14, 2001

PAPA

First Carbon Explorers Deployed in the N. Pacific at PAPA April 10 2001

Bishop, J.K.B., R.E. Davis and J.T. Sherman (2002) Robotic Observations of Dust Storm Enhancement of Carbon Biomass in the North Pacific. Science 298, 817-821. [LBNL #50120]

Carbon Explorers at OWS PAPA 50N 145W2001: Dawn 1000 - 0 m; Dusk 300 - 0 m; Noon 300 - 0 m; Sleep at 300 m2003: Dawn 1000 - 0 m; Dusk 300 - 0 m; Noon 300 - 0 m; Sleep 120, 250, 800 m

(2003)AntifoulingMethod Leads to CarbonFlux Index

Carbon Flux Index Concept:

AFTER SLEEP PERIOD1) Read Transmissometer2) Start CTD Pump to ‘blow off’ accumulated particles. 3) Read Transmissometer

Carbon Flux Index = (3)-(1) (Time at 100 m)

Bishop et al. Science, 304, 417-420, 2004

Transmissometer

Exhaust from CTD

pump

Particles Accumulate Here