Geoscience Reference
In-Depth Information
What is the stability of the sea ice cover, what are the effects of radiative
feedback in the Arctic and how do they modulate global ocean circulation?
What is the role of continental shelves in the cycling of C, N, Si and other
chemicals?
What is the productivity of the Arctic Ocean, and what is the structure and
diversity of higher trophic levels?
What are the effects of environmental changes, both of climate and of pollutants
and contaminants such as the introduction of POPs into the food chain?
There are numerous other problems related to the Arctic Basin. For example,
glaciers and ice sheets modulate global sea level by storing water deposited as snow
on the surface and discharging water back into the ocean through melting and via
icebergs. At present time, the study of these processes is made easier by means of
satellite observations. Existing satellites make possible monitoring of Polar
Regions, location of the ice layer and measurements of the topography and prop-
erties of the glacier bed as well as ice thickness.
Of particular interest is the high-latitude climate dynamics. According to Weller
and Lange (1999),
“
While considerable uncertainty still exists about the exact
nature of the future impacts of global climate change, there can no longer be any
doubt that major changes in the climate have occurred in recent decades in the
Arctic, with visible and measurable impacts following the climatic changes. Greater
impacts are likely in the future and while some of them will be positive, others will
be detrimental to human activities
.
Recent analysis of ice cores from the Arctic (Everett and Fitzharris 2001) has
revealed large-scale and rapid paleo-climate changes. Rapid warming took place
*
”
11,500 years ago, at the end of the last glacial period. The coldest parts of ice
cores had been as much as 21
C colder than the present temperature in Central
Greenland; and the temperatures increased by more then 10
°
C in a few decades.
There is evidence of even more rapid change in the precipitation pattern, rapid
changes of atmospheric circulation, and periods of rapid warming during the past
20,000 years. Rapid temperatures increase of
°
C in a few decades during the
last glacial period in Central Greenland had been followed by periods of slower
cooling over a few centuries and then a generally rapid return to glacial conditions.
About 20 such intervals, each lasting between 500 and 2,000 years, occurred during
the last glacial period.
It has been emphasized (Everett and Fitzharris 2001; Singer 2008; Vakulenko
et al. 2004) that the polar systems are extremely sensitive to the variations in
temperature, and several aspects of these systems will be affected by any further
climate change. The primary impact will be on the physical environment, including
ice, permafrost, and hydrology; on biota and Ecosystems, including
10
°
*
fisheries and
terrestrial systems; and on human activities, including social and economic impacts
on settlements, on resource extraction and transportation, and on existing infra-
structure. Scenario predictions of potential future global warming indicate a
necessity to particularly take into account various phenomena such as thermocarst
Search WWH ::
Custom Search