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

Atlantic Water pathways in the Arctic Polyakov et al., 2012

Barents Sea Sea ice extent Surface circulation

Winter Sea Ice Concentration (SSMR - SSM-I) Northern mode and Eastern mode SIC standard deviation (1979-2011) Northern Mode Eastern Mode Sea ice area R= 0.38

Regression of the SIC on Northern and Eastern modes Eastern Mode Index Northern Mode Index

ORCA025 Arctic-Atlantic configuration ERA-I forcing (1979-2011) Lag 0 Wind stress Sea ice production Northern Mode  Northerly winds Eastern Mode  Easterly winds

Ocean impact on the Northern mode Climatology Correlation BSO heat transport on Northern Mode Regression on the Northern mode Lag 0 Ouflow Inflow Net

Reemergence of the AW temperature anomalies Regression of temperature at 110 meters on the northern mode at lag -1 year Lag -1 year Correlation BSO heat content on Northern Mode Ocean heat content Divergence of heat transport Surface heat flux

Regression of winter SLP Impact of the SST anomalies on the atmosphere (and SIC) ? Regression of winter SLP on October SST Regression of OND SST on the Northern Mode

Atlantic Water pathways in the Arctic

Fram Strait Temperature Observations Model Fram Strait Longitude

Atlantic Water proprerties in Fram Strait in winter (JFM) Eof1 temperature 38% Eof1 Velocity 34% Eof1 heat transport 48% PC1s Temperature Velocity Heat transport Correlation: Velocity – Heat transport = 0.88 Temperature - Heat transport = 0.50

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

localized circulation in the Barents Sea Regression the current at 230 meters on PC2 of velocity in the WSC localized circulation in the Barents Sea

Atlantic Water temperature (230 m) Regression on PC1 of temperature in Fram Strait Lag -1 year Lag 0 Temperature anomalies over the Barents Sea + Fram Strait Branch

Constant passive tracer sources : BSO Fram Strait (0-800 m) Distribution of passive tracers at 230 meters Fram Strait Branch Barents Sea Branch 2008

Variability of the Atlantic Water Interannual variability at Kola Section Model Observations Seasonal variability if the fram Strait Branch North of Svalbard off Laptev Sea

Vertical distribution of passive tracers and temperature Fram Strait Branch Barents Sea Branch Off Laptev Sea 2008 Core of the FSB tracer coïncides with the temperature maximum Maximum of the BSB tracer along the coast

Propagation of two strong warming events 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

West of St Anna Trough Off Laptev Sea FSB Tracer BSB Tracer Temperature Correlation: 0.78 Correlation: -0.78 Correlation: 0.48 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 …

The research leading to these results has received funding from the European Union 7th Framework Programme (FP7 2007-2013), under grant agreement n.308299 NACLIM www.naclim.eu