1. 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

2. 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)

3. The Ocean Weather Ships in the North Atlantic 1947-onward

4. 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

5. 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

6. The Ocean Weather Ships in the North Atlantic X X X X X X X X X X X X 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”

7. Post 1950 Civil Aviation Jet EngineExtended range and altitude

8. Ocean Weather Station M “Polarfront” Greenland Scandinavia Situated at 66°N 2°E in the Norwegian Sea

9. 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 H å kon 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!

10. “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]

11. 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  pCO2 in surface water and atmosphere since 2005   13 C since 2006  Direct air-sea flux measurements since 2006 (NOC&Gfi/BCCR)  Plankton  ++++

12. 61 years in the Nordic Seas Temperature & salt anomalies DIC Temperature Oxygen

13. The warming of the Nordic Seas Deep Water A tale of three deep basins EurasianBasinGreenlandSea NorwegianSea Connected by two passageways Fram Strait Jan Mayen Channel

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

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

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

17. Spreading of Intermediate from the Greenland Sea Greenland Sea Norwegian Sea M High O2

18. Greenland Sea Deep Water GSDW The properties of GSDW started to crawl away from those of GSSW and towards those of AODW (EBDW) Low O2 High O2

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

20. 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

21. Hydrographical observations from the deep Norwegian Sea NOT/SDATA NISE+ (Nilsen & Hatun 2009)

22. Temperature at 3000 and 3500 m Below the sill depth in the Norwegian Sea (Basin) (in the homohaline and adiabatic layer) 3000 m3500 m

23. Ongoing Convection Ice cover Arctic Ocean Greenland Sea Norwegian Sea Atlantic Ocean Convection Sites Geothermal Heating 60 mW/m2 M

24. Recent warming of the deep water in the Norwegian Sea Ice cover Arctic Ocean Greenland Sea Norwegian Sea Atlantic 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

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

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

27. Thank you!

28. Confused? Time for questions or lunch