Tracer Hydrography in the Canadian Archipelago & Baffin Bay

Part I: Nutrients

Kelly K. Falkner, Kumiko Azetsu-Scott , Eddy CarmackE. Peter Jones , Robie Macdonald, Fiona McLaughlin

Chris Measures , Humfrey Melling , Andreas MuenchowMary O’Brien, Karen Selph, Peter Strain

Surface Circulation

Sill depths in m

Davis Strait 675

Barrow Strait 125

Cardigan Strait 180

Hell Gate 125

Kane Basin 220

Fury and Hecla 90

Davis St

F&H

Barrow

Card&Hell Kane

1916-2003 Hydrographic Data Analysis

Zweng, M.M. and A. Münchow (2005) Warming and Freshening of Baffin Bay, 1916-2003. J. Geophys. Res., in press.

Zweng, M.M. (2004) Hydrography and climatological evolution of Baffin Bay, 1916-1999, MSc., University of Delaware, pp. 1-

71

Dep

th (

km)

Dep

th (

km)

Significant warmingbelow 600-m

Significant fresheningabove 300-m

Baffin Bay (67N-80N)

Jones, E. P., J. H. Swift, L. G. Anderson, M. Lipizer, G. Civitarese, K. K. Falkner, G. Kattner, F. McLaughlin and J. Olafsson (2003) Tracing Pacific water in the North Atlantic Ocean, Journal of Geophysical Research, 108(C4), 3116, doi:10.1029/2001JC001141.

Arctic Ocean N-P Relationship

USCGC Healy Aug 2003

Baffin Bay Section: T-S-N*N* = (NO3 - 16xPO4 + 2.90 µM/kg)

Baffin Bay Section: N-P-O2-Si

Robeson Channel: T-S-%Pac

Robeson Channel: N-P-O2-Si

Smith Sound: T-S-%Pac

Smith Sound: N-P-O2-Si

CCGS Hudson Aug 1977

CCGS Louis S. St. Laurent

Aug 1997

0

20

40

60

80

100

120

28.000 29.000 30.000 31.000 32.000 33.000 34.000 35.000

salinity

Si µM

Hudson 1977 Stn19St. Laurent 1997Healy 2003Hudson 1977 Stn 18

Central Baffin Bay Si

Smith Sound Si

0

5

10

15

20

25

30.000 31.000 32.000 33.000 34.000 35.000

salinity

Si µM

Hudson 1977St. Laurent 1997Healy 2003Robeson 2003

Jones Sound

0

5

10

15

20

25

30

35

40

45

30.000 31.000 32.000 33.000 34.000 35.000

salinity

Si µM

St. Laurent 19971977 stn 481977 stn 491977 stn 511977 stn 471977 stn 451977 stn 461977 stn 50

Lancaster Sound

0

5

10

15

20

25

30

35

40

28.000 29.000 30.000 31.000 32.000 33.000 34.000 35.000

salinity

Si µM

Hudson 1977St. Laurent 1997

Arctic oscillation index

Blue line: cold season averageBlack line: 5 year running meanIndex is 1000 mb height anomalies mapped onto leading EOF 1997-2000

From Häkkinen & Proshutinsky (2004) Freshwater content variability in the Arctic Ocean, JGR 109, C03051

Conclusions vis a vis Nutrients

Substantial interannual variability in sounds & upper Baffin Bay: rivals seasonal?

Significant along channel mixing occurs in straits

Denitrification evident in deep (>600 m) Baffin Bay & Hudson St

Changes in Arctic Ocean throughput possibly related to AO?