Ocean Weather Ship Station M 1948-2009

The end of the North Atlantic Weather Ship era

Svein Østerhus and Tor Gamelsrød

WWW.BJERKNES.UIB.NO

Outline

Short about the history of the North Atlantic Weather Ships

Results from Weather Ship Station M– Changes in the deep Norwegian Sea

Future for station M (66°N, 2°E)

The Ocean Weather Ships in the North Atlantic1947-onward

North Atlantic Civil AviationPropeller-driven aircraft

DC-3

Transcontinental air service

With the expansion of civil aviation and growing understanding of the impact of aerological observations on weather forecasts after World War II, ICAO (The International Civil Aviation Organization) demanded a greater network of aerological stations, primarily in the North Atlantic

History of the North Atlantic Ocean Weather Ships International Civil Aviation Organisation (ICAO) and IMO

(WMO) established a net of Weather Ships Stations in the North Atlantic in 1947/48

USA, Canada and eighth European countries operated the stations

13 stations (A-M) 30 Ship More than 1000 seamen's

The Ocean Weather Ships in the North Atlantic

XX

X X

X

X

X

X X

X

XX

History International Civil Aviation Organisation

(ICAO) and IMO (WMO) established a net of Weather Ships Stations in the North Atlantic in 1947/48

13 stations (A-M) 30 Ship More than 1000 seamen's OWS “Polarfront” at M was the last

weather ship in service but was terminated November 2009 after 61 years.

“Polarfront” I and II“Cumulus”“Polarfront”

Post 1950 Civil Aviation

Jet Engine Extended range and altitude

Ocean Weather Station M“Polarfront”

Gre

enla

nd

Scan

dina

via

Situated at 66°N 2°E in the Norwegian Sea

Scientific research programICAO (NOT ICES) attempted to organize an international oceanographical research programme for the weather ships, but failed due to lack of interest, shortage of money and difficulties in procuring the necessary scientific equipment.

In Norway, a small group of three scientists, led by the oceanographer Håkon Mosby from the University of Bergen, took upon themselves to implement an extensive research programme on station M.

But they didn't have money to pay for the equipment!

“Dr. Petterssen opplyste at det var nødvendig at winchene ble montert i England dersom det skulle bli mulig å få en del av utgiftene over på svenskene og briterne”

“Dr. Petterssen wrote that it was essential to install the winches in England to make it possible to transfer some of the expenses to the Swedes and the British”

“Vi er blitt enige om å ta hydrografwinchenene med på budsjettet og håper at svenskene ikke gjør vanskeligheter”

“We have agreed on adding the hydrographical winches to the budget (for met obs. etc) and hope the  Swedes don’t make any trouble” [Sweden paid 43%, UK 35%, Norway 22%] + (thermometers from Germany and France).

Though the setting-up the hydrographic observation programme was not without a little skulduggery! [extracts of letter from Mosby to his friends]

Observations at station M

Met obs Temperature & salinity since 1948 Dissolved oxygen since 1953 Atmospheric CO2 since 1978 (NOAA) Nutrients and chlorophyll since 1991 DOC during 1991-1993 DIC during 1991-1994 DIC and alkalinity since 2001 pCO2 in surface water and atmosphere

since 2005 d13C since 2006 Direct air-sea flux measurements since

2006 (NOC&Gfi/BCCR) Plankton ++++

61 years in the Nordic Seas

Temperature & salt anomalies

1950 1960 1970 1980 1990 2000

Year

-0 .9

-0 .8

-0 .7

Te

mp

era

ture

°C

1500

1200

2000

1950 1960 1970 1980 1990 2000

Year

6.9

7

7.1

Dis

olv

ed O

xyg

en (

ml/l

)

1500

1200

2000

DIC

Temperature

Oxygen

The warming of the Nordic Seas Deep WaterA tale of three deep basinsEurasian

Basin

Greenland Sea

Norwegian Sea

Connected by two passageways

Fram Strait

Jan Mayen Channel

Greenland Sea Convection (pre-1970)

Ice cover

Arctic Ocean Greenland Sea Norwegian SeaAtlantic Ocean

Convection Sites

Arctic OceanDeep Water(AODW)

AODW

GSDW

AODW + GSDW

NSDW

GSSW

M

Greenland Sea Convection (today)

Ice cover

Arctic Ocean Greenland Sea Norwegian SeaAtlantic Ocean

Convection Sites

Arctic OceanDeep Water(AODW)

AODW

GSDW? NSDW?

AODW + ?

M

Temperature and Dissolved Oxygen in the Norwegian Sea Deep Water (NSDW) at M

1950 1960 1970 1980 1990 2000

Year

6.9

7

7.1

Dis

olv

ed O

xyg

en (

ml/l

)

1500

1200

2000

1950 1960 1970 1980 1990 2000

Year

-0 .9

-0 .8

-0 .7

Te

mp

era

ture

°C

1500

1200

2000

Spreading of Intermediate from the Greenland Sea

Greenland Sea Norwegian SeaM

High O2

34.86 34.87 34.88 34.89 34.9 34.91 34.92-1.5

-1.4

-1.3

-1.2

-1.1

-1

-0.9

-0.8

Salinity

Po

ten

tial T

em

pe

ratu

re (

°C)

GSSW

NSDW

EBDW

1982

2004

2004

Greenland SeaDeep Water

GSDW

The properties of GSDW started to crawl away from those of GSSW and towards those of AODW (EBDW)

Low O2

High O2

Temperature and Dissolved Oxygen in the Norwegian Sea Deep Water (NSDW) at M

1950 1960 1970 1980 1990 2000

Year

6.9

7

7.1

Dis

olv

ed O

xyg

en (

ml/l

)

1500

1200

2000

1950 1960 1970 1980 1990 2000

Year

-0 .9

-0 .8

-0 .7

Te

mp

era

ture

°C

1500

1200

2000

Changes in the deepest part of the Norwegian Sea (Basin)

Homohaline– No changes in salinity from

2500 m to the bottom– Almost homohaline from

1400 m in 1994 and from 800 m in 1935

Adiabatic– No changes in the

potential temperature from 2500 m to the bottom

Norwegian SeaDeep W ater

1994

-1 .10 -1.00 -0.90 -0.80 -0.70 -0.60Potentia l Tem perature (°C )

4000

3000

2000

1000

Pre

ssu

re (

dbar

)

34.9 34.905 34.91Salin ity

Ø sterhus 190608

Hydrographical observations from the deep Norwegian Sea

NOT/SDATA

NISE+ (Nilsen & Hatun 2009)

Temperature at 3000 and 3500 m Below the sill depth in the Norwegian Sea (Basin)

(in the homohaline and adiabatic layer)

1955 1960 1965 1970 1975 1980 1985 1990 1995 2000

-1.12

-1.1

-1.08

-1.06

-1.04

-1.02

-1

-0.98

-0.96

Pot

. te

mp

(C

)

Time (yrs)

Mean Pot. temp (C) at 3500 100 m depth in the Nordic sea : 6W - 2E, 63N-69N

1955 1960 1965 1970 1975 1980 1985 1990 1995 2000

-1.12

-1.1

-1.08

-1.06

-1.04

-1.02

-1

-0.98

-0.96

Pot

. te

mp

(C

)

Time (yrs)

Mean Pot. temp (C) at 3000 100 m depth in the Nordic sea : 6W - 2E, 63N-69N

3000 m 3500 m

Ongoing Convection

Ice cover

Arctic Ocean Greenland Sea Norwegian SeaAtlantic Ocean

Convection Sites

Geothermal Heating 60 mW/m2

M

Recent warming of the deep water in the Norwegian Sea

Ice cover

Arctic Ocean Greenland Sea Norwegian SeaAtlantic Ocean

Cooling

Heating

Intermediate depth (1000-1500 m):Warming due to warmer water convected in The Greenland Sea

2000 M: Warming due to lack of GSDW (replaced by AODW)

Below 2500 m:Warming due to geothermal driven convection and heating

Future for the station M time series?

The End?

TerminatedNov. 2009 and will not return!

FutureNew moorings and gliders will replace OWS Polarfront

FundedIn service 2011?

DeployedJan 2010

FundedTo be deployed2011(IMR)

4 stk. G lasskuler

4 stk. G lasskuler

3 stk. G lasskuler

W ire 100m

250kg

R C M -9

R C M -9

R C M -9

9 00 m k ev la r

3 00 m k ev la r

8

2 g la ssk u le r

A rgo ssen d er

Unmanned Sailing boat

Thank you!

Confused?

Time for questions or lunch