PowerPoint Presentation

Ocean Weather Ship Station M 1948-2009

The end of the North Atlantic Weather Ship era

Svein sterhus and Tor GamelsrdWWW.BJERKNES.UIB.NOOutlineShort about the history of the North Atlantic Weather ShipsResults from Weather Ship Station MChanges in the deep Norwegian Sea Future for station M (66N, 2E)

The Ocean Weather Ships in the North Atlantic1947-onward

3North 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 AtlanticHistory 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 1947/48USA, Canada and eighth European countries operated the stations13 stations (A-M)30 ShipMore than 1000 seamen's

5The Ocean Weather Ships in the North Atlantic

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HistoryInternational Civil Aviation Organisation (ICAO) and IMO (WMO) established a net of Weather Ships Stations in the North Atlantic in 1947/4813 stations (A-M)30 ShipMore than 1000 seamen'sOWS Polarfront at M was the last weather ship in service but was terminated November 2009 after 61 years.

Polarfront I and IICumulusPolarfront

Post 1950 Civil Aviation Jet Engine Extended range and altitude

Ocean Weather Station MPolarfront

GreenlandScandinaviaSituated at 66N 2E in the Norwegian SeaScientific 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 Hkon 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 ndvendig at winchene ble montert i England dersom det skulle bli mulig f en del av utgiftene over p svenskene og briterneDr. 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 BritishVi er blitt enige om ta hydrografwinchenene med p budsjettet og hper at svenskene ikke gjr vanskeligheterWe have agreed on adding the hydrographical winches to the budget (for met obs. etc) and hope the Swedes dont 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 obsTemperature & salinity since 1948Dissolved oxygen since 1953Atmospheric CO2 since 1978 (NOAA)Nutrients and chlorophyll since 1991DOC during 1991-1993DIC during 1991-1994 DIC and alkalinity since 2001pCO2 in surface water and atmosphere since 2005d13C since 2006Direct air-sea flux measurements since 2006 (NOC&Gfi/BCCR)Plankton ++++

61 years in the Nordic SeasTemperature & salt anomalies

DICTemperatureOxygen

The warming of the Nordic Seas Deep WaterA tale of three deep basinsEurasian BasinGreenland SeaNorwegian SeaConnected by two passagewaysFram StraitJan Mayen ChannelGreenland Sea Convection (pre-1970)Ice coverArctic OceanGreenland SeaNorwegian SeaAtlantic OceanConvection SitesArctic OceanDeep Water(AODW)

AODWGSDWAODW + GSDWNSDWGSSWM14Greenland Sea Convection (today)Ice coverArctic OceanGreenland SeaNorwegian SeaAtlantic OceanConvection SitesArctic OceanDeep Water(AODW)

AODWGSDW?NSDW?AODW + ?MTemperature and Dissolved Oxygen in the Norwegian Sea Deep Water (NSDW) at M

16Spreading of Intermediate from the Greenland Sea

Greenland SeaNorwegian SeaMHigh O217

Greenland SeaDeep WaterGSDWThe properties of GSDW started to crawl away from those of GSSW and towards those of AODW (EBDW)Low O2High O218Temperature and Dissolved Oxygen in the Norwegian Sea Deep Water (NSDW) at M

19Changes in the deepest part of the Norwegian Sea (Basin)HomohalineNo changes in salinity from 2500 m to the bottomAlmost homohaline from 1400 m in 1994 and from 800 m in 1935AdiabaticNo changes in the potential temperature from 2500 m to the bottom

20Hydrographical observations from the deep Norwegian Sea

NOT/SDATANISE+ (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 m3500 mOngoing ConvectionIce coverArctic OceanGreenland SeaNorwegian SeaAtlantic OceanConvection SitesGeothermal Heating 60 mW/m2M23Recent warming of the deep water in the Norwegian SeaIce coverArctic OceanGreenland SeaNorwegian SeaAtlantic OceanCoolingHeatingIntermediate depth (1000-1500 m):Warming due to warmer water convected in The Greenland Sea2000 M: Warming due to lack of GSDW (replaced by AODW)Below 2500 m:Warming due to geothermal driven convection and heating24Future for the station M time series?

The End?

TerminatedNov. 2009 and will not return!25FutureNew moorings and gliders will replace OWS Polarfront

FundedIn service 2011? DeployedJan 2010FundedTo be deployed2011(IMR)

Unmanned Sailing boat

Thank you!Confused?Time for questions or lunch28