Geoscience Reference
In-Depth Information
five) sub-systems of the climate
system, which in turn is a sub-system of the global system. Nowadays, a crucial
problem is that of climate change and its impacts. Frequently, with the term
“
Cryosphere and atmosphere are two (of the
we mean the occurrence of abnormal meteorological phenomena
(e.g. heat-waves, tornadoes,
climate change
”
floods, etc.), considering sometimes that it is a result of
the uncontrolled human activities, ignoring completely the natural variability. Thus,
we reach to conclusions about the climate system states, taking into account one or
a few parameters of one of its sub-systems only, assuming that the rest parameters
and the other sub-systems remain constant. It is obviously a
fl
flaw that leads to a
vicious circle. We should not ignore that the climate subsystems are in a continuous
interaction that is taking place, in general, between non-linear interactive processes.
A typical example is the interaction between cryosphere and atmosphere, which is
not only limited at their interface. Many authors are aimed in current research to
fl
find new links connecting these interactive processes which could shed light to
various climate mechanisms that still remain under investigation.
Nowadays, it is generally recognized that under the global warming conditions,
the high latitude regions will be more sensitive to the induced impacts. Speci
cally,
the increase in the surface air temperature (SAT) will be more signi
cant at the
above-said geographical area and the response of the cryosphere to this atmospheric
effect will be more considerable over Arctic and Sub-Arctic, than elsewhere. Since
the late of 19th century, observational data revealed that, SAT in Eastern Siberia
has increased by 10
C on an annual
basis. In particular, the SAT increase was most pronounced in the second half of the
20th century (especially in the 1970
°
C during wintertime, and by almost 2.0
3.5
°
-
1980s).
The environmental changes at the Arctic and Sub-Arctic regions are of crucial
importance for the additional reason that their ecosystems are considerably more
vulnerable to anthropogenic forcings, than the corresponding ecosystems of other
latitudes, mainly because the processes in the Arctic and Sub-Arctic environments
are relatively slower. For example, the living organisms in the permafrost eco-
systems live in the polar climate, where the vegetation period is seriously restricted.
There,
-
cant time delays and the
capacity to neutralize the effects of human activity appears to be weak. In addition,
the Arctic and Sub-Arctic ecosystems have speci
the feedback mechanisms operate with signi
c boundary conditions that are
closely associated with the permafrost boundary that reduce its ability to recover.
A quantitative forecast of changes in the balance of water, heat and carbon in the
cryogenic ecosystems of the Eastern Siberia (e.g. forest and tundra) under global
climate change conditions, requires:
long time-series of ground-based and satellite observations in order to regularly
monitor the accumulating ability of cryolithozone ecosystems, as well as
development of adequate models providing the regional balance of carbon.
Another serious impact of the SAT increase is the ice melting, which results in
the release into the troposphere and sometimes in the stratosphere of substantial
amounts of the heat-trapping carbon dioxide and methane emitted from the cryo-
sphere, thus accelerating the climate change (e.g. by enhancing the formation of
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