Geology Reference
In-Depth Information
that prevails in the polar regions. Such motion was
discovered in the Arctic basin in 1893 when the Norwegian
explorer Fridtjof Nansen sailed to the Arctic on a
specially built ship that was designed to sail through sea
ice. He wanted to prove that the Arctic current flowed
from Siberia westward to Greenland (see Figure 2.52).
To do that he boarded with his team on the ship “Fram”
(meaning forward), which was purposely let caught up in
the Arctic ice near New Siberian Islands off the coast
of Siberia. The ship indeed moved with the pack ice but
rather slowly and erratically [
Berens
, 2010]. However, it
has been proven later that the driving force for this large
scale ice motion was the surface wind, not the ocean cur-
rent as Nansen assumed. The wind acts through the fric-
tional drag of the rough ice surface.
There are two primary wind patterns in the Arctic that
drive large‐scale ice motion: (1) the Beaufort Sea Gyre
(BSG) and (2) the Transpolar Drift Stream (TDS)
(Figure 2.52). The first causes the ice cover to circulate
around the Arctic basin for several years, while the second
Figure 2.52
Wind patterns that drive Arctic Ocean circulation. Image courtesy of Arctic Monitoring and Assessment Programme
(AMAP), AMAP [1998] (source NSIDC).
