NABOS observaIons evaluate shift to more dynamic state of the

NABOSobserva'onsevaluateshiAtomoredynamic
stateoftheeasternArc'cOcean
by
AndreyPnyushkovandNABOSteam
(andrey@iarc.uaf.edu)
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.