AOOSMMee'ng,Sea,le,WA.November18,2015

NABOSobserva'onsevaluateshiAtomoredynamicstateoftheeasternArc'cOcean

byAndreyPnyushkovandNABOSteam

(andrey@iarc.uaf.edu)

NSF

2015RecoveredNABOSmooringsNABOS=NansenandAmundsenBasinsObservaEonalSystem

(8moorings:M6,M11,M12,M13,M14,M15,M16,andM3)

EurasianBasin

2015RecoveredNABOSmoorings(8moorings:M6,M11,M12,M13,M14,M15,M16,andM3)

Date MooringID RecoveryPosiEon Depth 1stSept2015 M1-1 7704.25N12548.28E 250m 1stSept2015 M1-2 7710.38N12547.52E 787m 2ndSept2015 M1-3 7739.29N12548.40E 1849m 20thSept2015 M1-4 7827.54N12553.76E 2721m 3rdSept2015 M1-5 8000.20N12559.67E 3430m 4thSept2015 M1-6 8108.18N12542.67E 3900m 7thSept2015 M3 7956.13N14214.89E 1350m 30thAug2015 M6-B 8205.98N9701.852E 2710m

RecoveredMcLaneProfilers(MMP)atthe125˚EsecEon

M13mooring

M15mooring M16mooring

Allmooringsprovidefulltwo-yearrecords

M12mooring

AtlanEcWater(AW)transportsthroughthe125˚Eline

Transports:Volume=4.6±0.2SvHeat=9.2±0.5TW(Tref=0˚C)

AccordingtoSchauerandBeszczynska-Möller(2009)andBeszczynska-Mölleretal.(2011)NetnorthwardheattransportinFramStraitis36±6TW,andAWvolumetransportis~4Sv.

AtlanEcWater(AW)transportthroughthe125˚Eline

~10%(0.4Sv)uncertaintyinAWtransportduetodatacoverage

M12 M13 M15 M16M14

SeasonalityofAWtemperature

M12:77ᵒ10’N

M13:77ᵒ39’N

- Strongamplitudeofseasonalsignal(>2ᵒC)- ShiAinphasesofTmax

SeasonalAmplitude(SA)ofAWcoretemperaturewas~0.4ᵒC(Pnyushkovetal.,2015)in2007-11orevensmaller(~0.25ᵒC;Dmitrenkoetal.,2009)in2004-07

Shelf-basinInteracEon

- StrongphaseshiAofseasonalpeaks- peaksintemperatureandcurrentspeeddonotmatch

M11

M12

SeasonalityofAWtemperature

~270m

Lowseasonalsignal

SeasonalityofAWtemperature

M15:80ᵒ00’N

M16:81ᵒ08’N

Noseasonalsignal

UpperoceantemperatureanomaliesArc'cReportCard2014,(arc'c.noaa.gov/reportcard)

>3ᵒCanomalyin2014intheeasternEB

SeaIceThicknessderivedfromCryoSatdata(h,p://www.cpom.ucl.ac.uk)

Upperoceantemperatureanomalies

Hightemperatures(Tmax>3˚C)atM3mooringin2014

Temperature,˚C

Tmax>3˚CHC≈200MJ/m2(Hice≈70cm)

Upperoceantemperatureanomalies

2014temperatureanomalieshaveregionalflavor,likelycausedbysea

icedistribu'on

M15mooring

M16mooring

Tmax=-1.1˚C

Tmax=-1.5˚CHC≈20MJ/m2(Hice≈7cm)

VelocityobservaEonsintheupperoceanlayerDownwardpropaga'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,potenEallylinkedtoicecondiEons.

•  InrecentyearswefoundindicaEonsofenhancedseasonalsignalinAWtemperaturedrivenbystrongershelf-basininteracEonintheEB.

•  RecoveredmooringsallowusesEmaEng2013-15heat(9.2TW)andvolume(4.2Sv)AWeastwardtransportsacrossthe125˚EsecEon.FurtherobservaEonaleffortsarerequiredtoevaluateinterannualchangesofthesetransports.