Photo: Bruce Molnia/U.S. Geological Survey |
The heat released by the North Atlantic current in the Nordic Seas contributes to the relatively mild climate of northwestern Europe. When the warm and saline water from the tropics gives up its heat to the colder atmosphere above, the ocean currents gradually cools. The amount of warm water carried by the ocean currents from the North Atlantic toward the Arctic is affected by the strength of the large-scale northerly winds blowing over the Nordic Seas. The model study of Iselin Medhaug and colleagues shows that stronger cold winds from the Arctic «spins up» the ocean circulation and contribute to force more water out of the Nordic Seas. This cold water is be replaced by an increased inflow of warm Atlantic water, which consequently contributes to Arctic sea ice retreat.
Referanse:
I. Medhaug, H. R. Langehaug, T. Eldevik, T. Furevik and M. Bentsen (2011): Mechanisms for decadal scale variability in a simulated Atlantic meridional overturning circulation. Climate Dynamics, doi: 10.1007/s00382-011-1124-z.