WWW BJERKNES UIB NO Ocean Weather Ship Station

WWW. BJERKNES. UIB. NO Ocean Weather Ship Station M 1948 -2009 The end of the North Atlantic Weather Ship era Svein Østerhus and Tor Gamelsrød

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 Atlantic 1947 -onward

North Atlantic Civil Aviation Propeller-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 History < < < X X X X < X X 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

Sc an din a via Gr ee nla nd Ocean Weather Station M “Polarfront” Situated at 66°N 2°E in the Norwegian Sea

Scientific research program ICAO (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!

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

Observations at station M < < < < Met obs Temperature & salinity since 1948 Dissolved oxygen since 1953 Atmospheric CO 2 since 1978 (NOAA) Nutrients and chlorophyll since 1991 DOC during 1991 -1993 DIC during 1991 -1994 DIC and alkalinity since 2001 p. CO 2 in surface water and atmosphere since 2005 d 13 C since 2006 Direct air-sea flux measurements since 2006 (NOC&Gfi/BCCR) Plankton ++++

61 years in the Nordic Seas DIC Temperature Oxygen Temperature & salt anomalies

The warming of the Nordic Seas Deep Water A tale of three deep basins Eurasian Basin Fram Strait Greenland Sea Jan Mayen Channel Norwegian Sea Connected by two passageways

Greenland Sea Convection (pre-1970) Greenland Sea Arctic Ocean Norwegian Sea M Convection Sites Ice cover GSSW AODW Arctic Ocean Deep Water (AODW) AODW + GSDW NSDW Atlantic Ocean

Greenland Sea Convection (today) Greenland Sea Arctic Ocean Norwegian Sea M Convection Sites Ice cover AODW Arctic Ocean Deep Water (AODW) AODW + ? GSDW? NSDW? Atlantic Ocean

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

Spreading of Intermediate from the Greenland Sea Norwegian Sea M High O 2

The properties of GSDW started to crawl away from those of GSSW and towards those of AODW (EBDW) Low O 2 Greenland Sea Deep Water GSDW High O 2

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

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

Hydrographical observations from the deep Norwegian Sea NO T/S DATA 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) 3000 m 3500 m

Ongoing Convection Greenland Sea Arctic Ocean Norwegian Sea Convection Sites M Ice cover Geothermal Heating 60 m. W/m 2 Atlantic Ocean

Recent warming of the deep water in the Norwegian Sea Greenland Sea Arctic Ocean Norwegian Sea Cooling Atlantic Ocean Ice cover 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 Heating

Future for the station M time series? The End? Terminated Nov. 2009 and will not return!

Future New moorings and gliders will replace OWS Polarfront Unmanned Sailing boat Funded In service 2011? Funded To be deployed 2011(IMR) Deployed Jan 2010

Thank you!

Confused? Time for questions or lunch