Workshop = Work in Progress

If only I could get organized

Data Overload

Loving it

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July/August 2003 ADCP Survey Volume Flux Summary

-0.70 Sv

-0.76 Sv

-0.63 Sv

-0.68 Sv

+4.3 Sv

-4.8 Sv

Greenland

0.70.07 Sv

1 Sv=106 m3/sor 5 Amazon R.or 200 Columbia R.

USCGC Healy ADCP Systems

Healy in snowy Seattle dry-dock

a bilge rat in the back?

well of the 75-kHz phased array?

system command and control

Ellesmere Island, Aug.-4, 3am:Start first ADCP survey

Greenland, Aug.-4, 6am:Finish first ADCP survey

Data Processing Challenge: Ice

ADCP Processing: Sorting and Screening Single Ping Data

water trackrelative to ship(true East, unsorted)

water trackrelative to ship(true North, unsorted)

water trackrelative to bottom(true North, sorted)

water trackrelative to bottom(true East, sorted)

Ensemble average

~ 1 hour

ADCP Calibration-1:Comparing ADCP to GPS-derived Ship’s Velocity Components

Looks good… but can’t really tell

North

East

Histogram Integrated Histogram

ADCP Calibration-2:ADCP-DGPS Velocity Vector Difference ( 2-min avg.)

Robeson ChannelADCP VelocityAug.-7-11, 2003

Measured

Detided =Measured-Tides

EllesmereIsland

108-m

108-m

•3-D detiding•2 constituents•Münchow (2000)•Local fit to data

•2-D detiding•8 constituents•Padman & Erofeeva (2004)•Global model + data assimilation

Two tidal removal techniques applied to Kennedy Channel

across-channel

along-channel

July/August 2003 ADCP Survey Volume Flux Summary

-0.70 Sv

-0.76 Sv

-0.63 Sv

-0.68 Sv

+4.3 Sv

-4.8 Sv

Greenland

0.70.07 Sv

1 Sv=106 m3/sor 5 Amazon R.or 200 Columbia R.

Greenland

EllesmereIsland

WindsAug. 2003:

Along 2003 ship track in Nares Strait

Winds during our survey and mooring work in Nares Strait were generally from the south and opposed the generally southward flow.

108-m

108-m

108-m

108-m

(a)

(d)

(c)

(b) 108-m

108-m 108-m

108-m

(a)

(c)(d)

(b)Robeson Channel Kennedy Channel, N

Smith Sound Kennedy Channel, S

July/August 2003 ADCP Survey Volume Flux Summary

-0.70 Sv

-0.76 Sv

-0.63 Sv

-0.68 Sv

+4.3 Sv

-4.8 Sv

Greenland

0.70.07 Sv

1 Sv=106 m3/sor 5 Amazon R.or 200 Columbia R.

108-m

303-m

Along-shore ADCP currentsJuly-27 through July-30, 2003:

Volume flux ~ -2.7 Sv

Is this theBaffin Island Current?

7/26, 03:00 to 7/29, 00:00 7/29, 00:00 to 7/30 09:00

108-m 108-m

Volume flux ~ -4.8 Sv

7/26, 03:00 to 7/29, 00:00

108-m

Along-shore ADCP currentsJuly-30 through July-31, 2003:

Volume flux ~ +4.3 Sv

Is this theWest Greenland Current?

First Mooring Result 2006

Ellesmere Island, Aug.-16, 2006: CT/CTD string recovery

Sadler (1976):Water, heat, and salt transports throughNares Strait, Ellesmere Island

0.1 m/s Greenland

EllesmereIsland 0 10 20

Distance (km)

100-m

300-m

500-m

700-m

5-week under-ice current measurements 1972

XX? ?? ADCP

CT/CTD

All recovered instruments have clean 3-year records

Low-pass-filtered depth-averaged CurrentsAugust 2003 through August 2006

km-03, Canada

km-24

km-30

km-34, Greenland

3 years

3-year record mean

2-day snapshot

Canada, km-03 Greenland, km-34

2004/05

2003/04

2005/06

Three-year along-channel currents from 2 ADCP mooringsD

epth

(m

)

Time (days) Time (days)

Time (Days)

Near surface

Near bottom

Three years of low-pass filtered current vectors

Time (Days)

km-03 km-30

Robeson Channel 82° 00’N -0.70 Sv coastally trapped

Kennedy Channel, N 81° 15’N -0.76 Sv broad channel flow

Kennedy Channel, S 80° 30’N -0.63 Sv broad channel flow

Smith Sound 78° 30’N -0.68 Sv coastally trapped

Thule Section 76° 30’N Lauren

Cape York 74° 30’N +4.3 Sv eddy train?

Baffin Island 72° 30’N -4.8 Sv ring?

Baffin Island, coastal 72° 30’N -2.7 Sv

Volume Transports from ADCP SurveysJuly/Aug. 2003

Baffin BayNares Strait

LabradorSea

Temperature

Latitude

Salinity

Surface Properties along 25-day USCGC Healy Ship Track

in 2003