The role of ocean heat transport variations for Arctic climate variations in the last millennium:
Climate variability in the Arctic is governed by complex interactions between the sub-systems ocean, atmosphere, and sea ice. The Arctic heat budget is determined not only by radiation, but also by lateral heat advection. While the magnitude of the mean meridonal heat transport is much bigger in the atmosphere compared to the ocean, anomalies are of similar magnitude on decadal time scales.
Paleoceanographic reconstructions from sediment cores and model simulations indicate considerable variations in the Atlantic inflow toward the Arctic with consequences for sea-ice extent, ocean-atmosphere heat exchange, and pan-Arctic temperatures.
During the last millennium, internal variability as well as variations driven by changes in the radiative forcing (solar activity, volcanic eruptions, greenhouse gas concentration) have contributed to respective changes in the oceanic circulation.
The heat input into the Arctic, in particular onto the Barents Shelf, is associated with positive feedbacks that contribute to the “Arctic Amplification”, i.e. amplified warming at high northern latitudes.