Contributions from: Norwegian Meteorological Institute(met.no) Norwegian Meteorological Institute(met.no) Geophysical Institute, University of Bergen(GfI-UiB)

Contributions from:Contributions from: Norwegian Meteorological InstituteNorwegian Meteorological Institute (met.no)(met.no) Geophysical Institute, University of BergenGeophysical Institute, University of Bergen (GfI-UiB)(GfI-UiB) Institute of Marine ResearchInstitute of Marine Research (IMR)(IMR) Nansen Environmental and Remote Sensing CenterNansen Environmental and Remote Sensing Center (NERSC)(NERSC)

NOClim PT 5NOClim PT 5Objectives and deliverables:Objectives and deliverables:

Did we deliver?Did we deliver?

Key contributors:Key contributors:Arne Melsom (met.no)Arne Melsom (met.no)Øystein Skagseth (GfI-UiB)Øystein Skagseth (GfI-UiB)Kjell Arne Mork (IMR)Kjell Arne Mork (IMR)Svein Sundby (IMR)Svein Sundby (IMR)Knut A. Lisæter (NERSC)Knut A. Lisæter (NERSC)

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Principal Task 5 objectives

to improve our understanding and description of seasonal and interannual variability of the water masses that flow into and within the Nordic Seas and Arctic Ocean, including the extent and fluxes

of sea ice

Key Questions (KQ)1. Does teleconnections by oceanic pathways give rise to

significant interannual variability in the AW inflow, or is the local wind forcing always the controlling mechanism for such variability?

2. By quantitative amounts, what is the seasonal and interannual variability in the AW inflow along its eastern and western branches?

3. By quantitative amounts, what are the seasonal and interannual variability, and trends, in the ice and ocean variables and fluxes of the Arctic Ocean?

4. What is the seasonal and interannual variability of the position and strength of the front between Atlantic Water and Arctic Water in the Nordic Seas?

4. What is the seasonal and interannual variability of the position and strength of the front between Atlantic Water and Arctic Water in the Nordic Seas?

Principal Task 5 deliverables

• publication in peer-reviewed scientific journals• oral presentations in international science

meetings and conferences• oral presentations in NOClim’s workshop• contributions to proceedings from NOClim

workshops• contributions to the NOClim project web site• contributions to progress reports and the final

report to the Norwegian Research Council

Key Question 1:Does teleconnections by oceanic pathways give rise to significant interannual variability in the AW inflow, or is the local wind forcing always the controlling mechanism for such variability?

Investigations focused on:• propagating SST anomalies• propagating SSS anomalies

COADS SST winter anomalies, 1970:

daSilva SST winter anomalies, 1970:

Reference domains:

Propagating SST anomalies

NortheasternNorth AtlanticOcean (NNAO)

SouthernNordic Seas

(SNS)

confidence levels:correlations:

5 yearsleading

5 yearsleading

10 yearsleading

Propagating salinity anomalies

Propagation speeds of salinity anomalies

y = 0,8764x + 0,6226R2 = 0,963

1

2

3

4

5

6

1 2 3 4 5 6

Faroe/Shetland - Kola Section (cm/s)

Fylla

Ban

k - N

ewfo

undl

and

(cm

/s) 1982-84

1967-72

1958-61

1986-90

1975-82

1961-65

Propagation speeds of salinity anomalies:Salinity in the subarctic gyre:

Fylla

New-foundland

Rockall

Kola

Relation between the NAO Index and Fluxes of the Subarctic Gyre

0

1

2

3

4

5

6

-1,0 -0,5 0,0 0,5 1,0 1,5

NAO Index

Prop

agat

ion

spee

d (c

m/s

)

1 1908-12

1967-72

Key Question 2:By quantitative amounts, what is the seasonal and interannual variability in the AW inflow along its eastern and western branches?

Investigations focused on:• interannual hydrographic variability• SSH variability• seasonal transport variability

1980

1985

1990

1995

2000

-2.5-2.3654-2-1.5-1-0.500.511.52

050100150200250300350

1980

1985

1990

1995

2000

Temperature and salinity anomalies in the Svinøy section averaged over 100-200m depth

-0.25-0.2-0.15-0.1-0.0500.050.10.150.20.25

T [oC]

S

Kilometre

shelf 200m 1000m

Svinøy section

Interannual hydrography anomalies in the Svinøy section

5,8

6,0

6,2

6,4

6,6

6,8

7,0

7,2

7,4

7,6

7,8

8,0

8,2

8,4

8,6

1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002

Tem

pera

ture

[ o C

]

-10

0

10

20

30

40

50

60

70

80

90

100

110

120

130

Area

[km

2 ]

Temperature

Area

March/April

6,8

7,0

7,2

7,4

7,6

7,8

8,0

8,2

8,4

8,6

8,8

9,0

1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002

Tem

pera

ture

[ o C]

20

30

40

50

60

70

80

90

100

110

120

130

Area

[km

2 ]

Temperature

Area

July/August

Area and mean temperature of the Svinøy section Atlantic Water

CEOF amplitude, mode 1, 64%

20 oW 10 oW 0o 10oE 20o E

60 oN

64 oN

68 oN

72 oN

76 oN

0.0320.0350.040.0450.050.0550.060.0650.070.075

Sea surface height variability and ocean circulation

92 93 94 95 96 97 98 99 00

2

-2

SSH vs. MSLP (1st principal components, normalized):

2

0

-295 96 97 98 99 00

SSS vs. NwASC (normalized time series):

SSS

NwASC

Coherence as a function of frequency

(in 1/months):

sea surface slope (SSS):SSS= [SSH(A) – SSH(B)]/dx

(Norwegian Atlantic Slope Current)

0 50 100 150 200 250 300 3502

3

4

5

6

7

8

day of year

Sv

Baroclinic transport in the Svinøy section during the year

datamodel (y)

y = 5.0 + sin (pi * (dag/180+0.87))

Seasonal transport variability in the Svinøy section

Key Question 3:By quantitative amounts, what are the seasonal and interannual variability, and trends, in the ice and ocean variables and fluxes of the Arctic Ocean?

Investigations focused on:• trends in the ice extent based on satellite-born instrument and historical records• dominant frequencies for ice extent

variability

Ice extent and ice area from passive microwave data

A century of ice extent and air temperature data

Ice border at 10°E in the Fram Strait

Data source: Norwegian Polar Institute

10°E

80°N