NABOS observaIons evaluate shift to more dynamic state of the
Transcription
NABOS observaIons evaluate shift to more dynamic state of the
NABOSobserva'onsevaluateshiAtomoredynamic stateoftheeasternArc'cOcean by AndreyPnyushkovandNABOSteam ([email protected]) AOOSMMee'ng,Sea,le,WA.November18,2015 NSF 2015RecoveredNABOSmoorings NABOS=NansenandAmundsenBasinsObservaEonalSystem (8moorings:M6,M11,M12,M13,M14,M15,M16,andM3) EurasianBasin 2015RecoveredNABOSmoorings (8moorings:M6,M11,M12,M13,M14,M15,M16,andM3) Date MooringID 1stSept2015 M1-1 1stSept2015 M1-2 2ndSept2015 M1-3 20thSept2015 M1-4 3rdSept2015 M1-5 4thSept2015 M1-6 7thSept2015 M3 30thAug2015 M6-B RecoveryPosiEon 7704.25N12548.28E 7710.38N12547.52E 7739.29N12548.40E 7827.54N12553.76E 8000.20N12559.67E 8108.18N12542.67E 7956.13N14214.89E 8205.98N9701.852E Depth 250m 787m 1849m 2721m 3430m 3900m 1350m 2710m RecoveredMcLaneProfilers(MMP) atthe125˚EsecEon M12mooring M15mooring M13mooring M16mooring Allmooringsprovidefulltwo-yearrecords AtlanEcWater(AW)transportsthroughthe125˚Eline Transports: Volume=4.6±0.2Sv Heat=9.2±0.5TW (Tref=0˚C) AccordingtoSchauerandBeszczynska-Möller(2009)andBeszczynska-Mölleretal.(2011) NetnorthwardheattransportinFramStraitis36±6TW,andAWvolumetransportis~4Sv. AtlanEcWater(AW)transportthroughthe125˚Eline M12 M13 M14 M15 M16 ~10%(0.4Sv)uncertaintyinAWtransportduetodatacoverage SeasonalityofAWtemperature M12:77ᵒ10’N - Strongamplitudeof seasonalsignal(>2ᵒC) - ShiAinphasesofTmax M13:77ᵒ39’N SeasonalAmplitude(SA)ofAW coretemperaturewas~0.4ᵒC (Pnyushkovetal.,2015)in 2007-11orevensmaller(~0.25ᵒC; Dmitrenkoetal.,2009)in2004-07 Shelf-basinInteracEon M11 M12 - StrongphaseshiAof seasonalpeaks - peaksintemperature andcurrentspeeddonot match SeasonalityofAWtemperature Lowseasonalsignal ~270m SeasonalityofAWtemperature M15:80ᵒ00’N Noseasonalsignal M16:81ᵒ08’N Upperoceantemperatureanomalies Arc'cReportCard2014, (arc'c.noaa.gov/reportcard) >3ᵒCanomalyin2014in theeasternEB SeaIceThicknessderivedfromCryoSat data(h,p://www.cpom.ucl.ac.uk) Upperoceantemperatureanomalies Hightemperatures(Tmax>3˚C)atM3mooringin2014 Tmax>3˚C HC≈200MJ/m2 (Hice≈70cm) Temperature,˚C Upperoceantemperatureanomalies 2014temperatureanomalieshave regionalflavor,likelycausedbysea icedistribu'on M15mooring Tmax=-1.1˚C Tmax=-1.5˚C HC≈20MJ/m2 (Hice≈7cm) M16mooring VelocityobservaEonsintheupperoceanlayer Downwardpropaga'onofNIWenergy M11 M12 M13 M14 VelocityobservaEonsintheupperoceanlayer SSM/I-SSMISDailyIceConcentraEon (nsidc.orgsite) SSM/I-SSMISDailyIceConcentraEon (nsidc.orgsite) SSM/I-SSMISDailyIceConcentraEon (nsidc.orgsite) SSM/I-SSMISDailyIceConcentraEon (nsidc.orgsite) Summary • 2013-15NABOSobservaEonssuggestthattheeasternEBisinits moredynamicstateindicaEngpossibleshietothe“newArcEc”. • Instrumentalmeasurementshaverevealedstrongwarmingofthe upperoceanlayerintheeasternEBin2014,potenEallylinkedto icecondiEons. • InrecentyearswefoundindicaEonsofenhancedseasonalsignalin AWtemperaturedrivenbystrongershelf-basininteracEoninthe EB. • RecoveredmooringsallowusesEmaEng2013-15heat(9.2TW)and volume(4.2Sv)AWeastwardtransportsacrossthe125˚EsecEon. FurtherobservaEonaleffortsarerequiredtoevaluateinterannual changesofthesetransports.