Geoscience Reference
In-Depth Information
Polar processes. Melting ice sheets and shrinking sea-ice extent and thickness
greatly affect not only the polar areas, but coastal regions all over the globe.
SPARC is teaming up with other interested research institutes to bring its
expertise to bear on scienti
c issues speci
c to the polar areas.
The project CliC, being a continuation and development of the programme
CCSS, is directed at further studies of the impact of processes in the Arctic on the
global climate formation. The related problems include: determination of the role of
the Arctic Ocean waters and ice cover dynamics as factors of strong changes of the
arctic climate; study of sensitivity of the arctic climate system to the growing
concentration of GHGs in the atmosphere. The urgency of these and other problems
is determined, in particular, by obtaining new data of observations, demonstrating
substantial changes of the global cryosphere, including:
a small extent of multi-year arctic ice cover (with minimum values in September
2002 and in 2003);
intensive melting of Greenland glaciers from the beginning of satellite obser-
vations in 1980 (note that according to the latest radio-altimeter data, the coastal
parts of glaciers have been melting, whereas in the centre of ice cover there was
an accumulation of ice); and
destruction of the ice shelf Larsen B in the region of Western Antarctic in 2002;
accelerated melting of mountain glaciers on all continents.
One of the important tasks of CliC is to study possible additional GHGs emissions
to the atmosphere in permafrost melting (Fig.
5.2
). It is known that permafrost, as a
critical part of the Earth
s climate system, covers 24 % of the land in the northern
hemisphere. It also stores approximately 1.5 trillion tons of carbon
'
twice the
amount of carbon currently in the atmosphere. The permafrost carbon feedback is not
present in the global climate change models used to estimate how warm the earth
could get over the next century. As a result of climate change, permafrost is at risk of
melting, releasing the stored carbon in the form of carbon dioxide and methane. As it
follows from Fig.
5.2
, permafrost structure is not uniform and depends on the land
covers. Therefore, a creation of permafrost database with spatial distribution of its
characteristics is principal stage of climate modeling processes.
An important circumstance is the impossibility of reliable short-range and long-
range climate forecasts without an adequate consideration of cryospheric processes
(Kondratyev and Johannessen 1993; Marshall 2011; Vallis and Thoumi 2012; Kerr
2000). This concerns, in particular, the solution of an important problem, such as
forecast of possible rise of the World Ocean level under conditions of global
climate warming. Some other global aspects of CliC include studies of: thermo-
haline circulation (fresh water in
—
ow to the North Atlantic); snow and ice covers;
reliable methods of taking into account the permafrost and ice cover dynamics in
climate models; changes of solid precipitation with the use of new methods of
observations.
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