Is the oceanic heat transport with Atlantic water towards the Arctic changing?

1. Is the oceanic heat transport with Atlantic water towards the Arctic changing? from space Heat by winds by ocean currents Steingrímur Jónsson, University of Akureyri & Marine Research Institute Héðinn Valdimarsson, Marine Research Institute, Reykjavik Bogi Hansen, Faroe Marine Research Institute, Tórshavn Karin Margretha H. Larsen, Faroe Marine Research Institute, Tórshavn Barbara Berx, Marine Scotland Science, Marine Laboratory, Aberdeen Toby Sherwin, SAMS, Scottish Marine Institute, Oban Steffen M. Olsen, Danish Meteorological Institute , Copenhagen Kerstin Jochumsen, Institut für Meereskunde, Universität Hamburg Svein Østerhus, Uni Research, Bergen image:AGU 2003 IAPSO 2013 P10S2.01

2. AGU, 2003 Transport (mass and heat) observatories1995-ongoing NACLIM MAIA

3. Tools Current meters (ADCP) Hydrography CTD-sections

5. AGU, 2003 Atlantic inflow volume transport Inflowing Atlantic water (millions m3/second) No trend !!!!!!!!!!!!!!!!!!!!!!!!! No trend No weakening Iceland branch Faroe branch Shetland branch image:AGU 2003

6. Atlantic inflow volume transport Inflowing Atlantic water (millions m3/second) Iceland branch Faroe branch Shetland branch image:AGU 2003

7. Total Atlantic Volume Inflow1997-2011 8.5 Sv (Østerhus et al. 2005) New results 0.7 Sv 7.0 Sv +- 1 Sv Hansen et al. 2010, Jonsson and Valdimarsson 2012, Berx et al. 2013

8. Combining in-situ measurements and altimetry to estimate volume, heat and salt transport variability through the Faroe Shetland Channel Berx, Hansen, Østerhus, K. M. Larsen, T. Sherwin, and K. Jochumsen, (2013).

9. Volume budget ”Old numbers” ( 1 Sv = 106 m3/s ) 2.5 Sv Q = 8.5 Sv (Østerhus et al. 2005) 6 Sv

10. Volume budget ”New numbers” ( 1 Sv = 106 m3/s ) 2.5 -? Sv Q = 7.0 +- Sv 6 -? Sv assumption: Bering Strait inflow ~ West of Greenland outflow. English Channel ~ NaN

11. Heat Transport Volume transport: Q Heat import = c · Q · ΔT ≈ c · Q · T Temperature: T Cooling: ΔT

12. Atlantic inflow temperature 1950 – 2010 Heat import = c · Q · T Shetland branch Faroe branch Iceland branch

13. Temperature changes from Rockall to Fram Strait 1950-2008 Temperature anomaly 0-500 m C Holliday et al. GRL (2008)

14. Temperature in Atlantic layer at station M1948-2010 Monthly mean Yearly mean

15. The effect of SPG shrinkage (Hakkinen & Rhines, 2004; Hátún et al., 2005) Before 1995 After 1995 Warmer and more saline

16. Observed and simulated gyre index (SSH averaged for 60°W–15°W, 48°N–65°N) Strong 3.0 1.5 0 Weak -1.5 -3.0 Lohman et al. (2009)

17. Weak and StrongGyre index Lohman et al. (2009) Strong 3.0 1.5 Atlantic Water Temperature in the Nordic Seas (M) 0 Weak -1.5 -3.0

18. Conclusions:There is no indication for a change in the volume transport,1997-2011 But there is an indication that the oceanic heat (and salt) transport towards the European Arctic has increased since 1995 due to increased water temperaturebut!

19. Confused? Please ask! www.naclim.eu www.folk.uib.no/ngfso Svein Østerhus

20. 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