BNL

INL

Lateral Transport of Dissolved and Particulate TEIs at Ocean Margins

K2-NW Pacific

% TransmissionAlong Line W

228Ra

Attributes of Line W as a GEOTRACES section

• Detailed hydrographic template within which to interpret geochemical profiles (proposed PO program to run until 2013).

• Frequency of cruises between Woods Hole and Bermuda facilitate re-occupation of stations along transect (Process studies? GEOTRACES Intercalibration Station?).

• Intersects with planned ORION/IOOS PIONEER program designed to characterize shelf-slope processes on NW Atlantic margin.

• Intersects major components of MOC (DWBC and Gulf Stream).

• Sharp, well-defined contrasts in water mass source/age/history.

• High productivity margin.

• Significant and distinct lateral particle fluxes in intermediate and bottom nepheloid layers.

• Prior and on-going sediment trap studies.

• Ideal for studies of elemental boundary scavenging.

• Potential western limb of an east-west transatlantic GEOTRACES section that interests major particle flux time-series stations.

http://www.whoi.edu/science/PO/linew/index.htm

PIONEER Array, Line W, and the Northeast Regional Coastal Ocean Observing System

Line WPioneer

Array

Deep

WesternBoundary

Curre

nt

On-going and planned physical oceanographicmeasurements along Line W (J. Toole et al.)

Moorings:

Fixed instruments (moorings 2,4,6)-T/C sensors- Vector averaging current meters (VACMs)

Moored Profilers (MMPs, moorings 1,3,5)- CTD- ADCP- Optical backscatter- Transmissometry (proposed)

1 2 3 4 5 6

Hydrographic survey cruises:

- CTD- Nutrients- Dissolved O2- I-129- CFCs/SF6

- Optical backscatter + transmissometry

(Joyce et al., 2005)

Composite mean property sections (1995 and 2006) along Line W. Average, net southward DWBC transport across Line W is estimated to be 16 Sv.

Recent and proposed biogeochemical flux studies on Line W

Sediment traps

0

50

100

150

200

250

300

W-Pacific Site-12-2304

Weddell_Sea_VIII_upper-2453

E-Pacific HOTS-1500m

Nordic Atlantic PARFLUX-Fram_Strait-FS-2400m

Atlantic Southern Ocean South_Georgia_Island-SGI-2000m

JGOFS-Equatorial_Pacific-EQPAC-9N-2150m

atlantic Southern Ocean Bouvet_Island-BO5-lower-2251m

Sargasso_Sea-OFP-1500m

N-AtlanticL1-94-2000m

E-Pacific MANOP-Site-S-1600m

N-Atlantic L1-93-2020m

JGOFS-Equatorial_Pacific-EQPAC-5S-avg of 2099, 2209,

2316m

N-Atlantic JGOFS-NABE-34N-2067m

JGOFS-Arabian_Sea-M5-2363m

Nordic Atlantic PARFLUX-Bear_Island-BI-1700m

JGOFS-Equatorial_Pacific-EQPAC-2N-2203mJGOFS-Equatorial_Pacific-EQPAC-5N-2100m

N-Atlantic L2-94-2000m

S-Atlantic Walvis_Ridge-WR3/4-LOWER-average of 1640 and

1648

Indo-German_Bay_of_Bengal-NBBTs-1717m avg of 2 years

W-Pacific Site_2-1769m

JGOFS-Equatorial_Pacific-EQPAC-Eq-2284m

E-Pacific MANOP-TP-C-1883m

W-Pacific JAST01-Okinawa_Trough-1547m

Indo-German_Bay_of_Bengal-NBBTn-1727m avg of 2 years

N-Atlantic Cape_Blanc-CB1/2-deep-2195m

Indo-German_Bay_of_Bengal-CBBT-2282m avg of 3 years

N-Atlantic Cape_Blanc-CB1-deep-2195m

W-Pacific Site_1_shallow-1590mE-Pacific Off_Chile-CH4-2300mJGOFS-Arabian_Sea-M3-1857mJGOFS-Arabian_Sea-M2-1974m

StW average three depths, 2 years

Average daily mass flux (mg/m2/d)

Line W(mooring @ 3000 m isobath)

The Northwest Atlantic Margin is characterized by high mass fluxes!

Global variations in mass fluxes for particles intercepted by sediment traps deployed within or below the mesopelagic zone

Line W Mooring deployment timelines (past and proposed)

Spring2004

Spring2005

Spring2006

Spring2007

Spring2008

3000 mTrap mooring

POmoorings

Proposed

WHOI funded

WHOI funded NSF-CO funded NSF-CO funded

NSF-PO funded NSF-PO funded NSF-PO funded NSF-PO funded

WHOI funded

Toole proposal

2000 mTrap mooring

4700 mTrap mooring

Spring2009

Spring2010

ProposedProposed

Toole proposal Toole proposal

Spring2012

PossiblePossible

Toole proposal Toole proposal

Spring2011

Proposed

Spring2013

Proposed

An E-W transatlantic GEOTRACES section?

LineW

BermudaOFP

ESTOC

PO measurement program consists of a moored array spanning the continental slope plus annual/semi-annual (spring and fall)

hydrographic survey cruises

http://www.whoi.edu/science/PO/linew/index.htm

Line W

Rasmussen (2003)

The NW Atlantic Margin: A Productive, dynamic and spatially heterogenous system

Three-day composite satellite SST (left) and chlorophyll concentration (right) for 18-20 June 2001.

Turbidity sensor measurements from MMP deployed at 3000 m (Station W)

Jan 30, 2005