Geoscience Reference
In-Depth Information
potential navigational routes through the Arctic Ocean. Rounding Africa or
South America for commerce with Pacific nations was not only time con-
suming, but also dangerous in the days of sailing ships. Maybe the most
famous trip North was the tragic Franklin expedition of 1845 in which 128
people on two ships disappeared. A total of 32 rescue attempts were carried
out. In 1878/9 Nordenskj¨ ld succeeded in exploring the North-East Passage,
and in the early twentieth century, Amundsen was the first to sail the North-
West Passage (1903/4). Finally, coming from Ellesmere Island, Peary stated
that he had reached the North Pole in 1909, a claim that is now doubted. My
personal favorite story is Fridtjof Nansen's drift with the Fram starting in
1896. His ship was built specifically for Arctic exploration with a hull made
out of oak, so that it could not easily be crushed by sea ice. He sailed along the
Russian and Siberian coasts, and at about 1508 E close to the New Siberian
Islands he turned north. With approaching winter, his ship froze in at close to
798 N and drifted with the sea ice. It had been known that the ocean currents
were generally to the west, as wood originating in Siberia had been found off
the coast of northern Scandinavia, however, not much was known about the
speed of the current and if such a trip would take a few months or many years.
In the event, three years later the Fram returned to Norway to a triumphant
welcome, having collected a great amount of climatological, sea ice and
oceanographic observations from the central Arctic Ocean.
In contrast to Antarctica, the surface characteristics are much more varied
in the Arctic. Here, besides snow cover, sea ice, and water, we also find
tundra, permafrost, taiga, and boreal forest. Different surface characteristics
affect the surface energy budget and hence result in a larger number of
different micro-climates.
5.8.2 Climatology
The Arctic region is the second energy sink on Earth. The radiative input from
the Sun is similar to Antarctica. However, during the northern summer, the
Earth-Sun distance is at its maximum, reducing the solar radiation on top of
the atmosphere by some 3%. On the other hand, owing to the increased
distance, the Earth's rotational speed around the Sun decreases, increasing
the length of the summer. In general, winters are long, typically between
6 and 9 months, and can be very cold. Summers are short but have an
abundance of sunlight, as day length is very long, highly important for the
growth of the vegetation.
Temperature
The coldest temperatures in the Northern Hemisphere are not found in the
central Arctic Basin, but in Eastern Siberia. In the central Arctic Ocean, sea
Search WWH ::
Custom Search