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. Transport (mass and heat) observatories 1995-ongoing
AGU, 2003
NACLIM
MAIA

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

5. Atlantic inflow volume transport
Inflowing Atlantic water
(millions m3/second)
AGU, 2003
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
Atlantic inflow volume transport
image:AGU 2003

7. Total Atlantic Volume Inflow 1997-2011
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 = Sv
6 -? Sv
assumption: Bering Strait inflow ~ West of Greenland outflow. English Channel ~ NaN

11. Heat Transport Heat import = c · Q · ΔT ≈ c · Q · T 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
Temperature anomaly m C
Holliday et al. GRL (2008)

14. Temperature in Atlantic layer at station M 1948-2010
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)
3.0
1.5
-1.5
-3.0
Strong
Weak
Lohman et al. (2009)

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

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

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 (FP ), under grant agreement n NACLIM