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Atlantic water transports to the Arctic and their impact on sea ice
C. Herbaut, M.-N. Houssais, A.-C. Blaizot and S. Close
LOCEAN, UPMC
Northern mode and Eastern mode
Winter Sea Ice Concentration (SSMR - SSM-I)
SIC standard deviation (1979-2011)
Northern ModeEastern Mode
Sea ice area
R= 0.38
Northern Mode Northerly winds
Eastern Mode Easterly winds
Wind stress Sea ice production
ORCA025 Arctic-Atlantic configuration ERA-I forcing (1979-2011)
Lag 0
Ocean impact on the Northern mode
Climatology
Regression on the Northern mode
Correlation BSO heat transport on Northern Mode
Lag 0
OuflowInflowNet
Regression of temperature at 110 meters on the northern mode at lag -1 year
Correlation BSO heat content on Northern ModeLag -1 year
Ocean heat contentDivergence of heat transportSurface heat flux
Reemergence of the AW temperature anomalies
Regression of OND SST on the Northern Mode
Regression of winter SLP on October SST
Impact of the SST anomalies on the atmosphere (and SIC) ?
Eof1 temperature 38% Eof1 heat transport 48% Eof1 Velocity 34%
Correlation:Velocity – Heat transport = 0.88Temperature - Heat transport = 0.50
Atlantic Water proprerties in Fram Strait in winter (JFM)
TemperatureVelocityHeat transport
PC1s
Atlantic Water circulation
Regression on PC1 of velocity at Fram Strait
Currents at 230 meters JFM SLP DJF
• Cyclonic circulation over the Nordic Seas + Arctic Ocean• Arctic Oscillation
Regression the current at 230 meters on PC2 of velocity in the WSC
localized circulation in the Barents Sea
Lag -1 year Lag 0
Regression on PC1 of temperature in Fram Strait
• Temperature anomalies over the Barents Sea + Fram Strait Branch
Atlantic Water temperature (230 m)
2008
Constant passive tracer sources : • BSO• Fram Strait (0-800 m)
Distribution of passive tracers at 230 meters
Fram Strait Branch Barents Sea Branch
Interannual variability at Kola Section
off Laptev Sea
Seasonal variability if the fram Strait Branch
ModelObservations
North of Svalbard
Variability of the Atlantic Water
Vertical distribution of passive tracers and temperature
Off Laptev Sea
2008
Fram Strait Branch Barents Sea Branch
• Core of the FSB tracer coïncides with the temperature maximum
• Maximum of the BSB tracer along the coast
Hovmoeller of Temperature along the slope of the Eurasien Basin
• Propagation of two strong warming events
• Strong decrease of temperature and tracer east of St Anna Trough
Temperature
Correlation: 0.48
FSB Tracer
West of St Anna Trough
Correlation: 0.78
Off Laptev Sea
BSB Tracer
Correlation: -0.78
Variability of the temperature in the core of the Atlantic branch linked with the variability of the exchange between the Barents and Fram Strait Branches.
Impact of the temperature variability in the FSB on sea ice properties
Climatological sea ice melt in winter (cm/d)
Regression of the sea ice melt in winter on PC1 of T in Fram Strait
• Hints of influence north of the Barents Sea
Next• Analyse the covariability of the AW branches in FS and BS• Diagnose ocean vertical heat fluxes and their impact on sea ice• Analyse the atmospheric modes linked to sea ice/SST variability• Other seasons …
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