The Arctic Environmental Problems - New Ecoinformatics Tools in Environmental Science: Applications and Decision-making - page 497

4. To enhance the observation and monitoring of the cryosphere in support of
process studies, model evaluation, and change detection.

Speci c questions that help de ne the primary tasks of CliC are:

(i) How stable is the global cryosphere?

How well do we understand and model the key processes involved in
each cryospheric component of the climate system?

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How do we best determine the rates of change in the cryospheric components?

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(ii) What is the contribution of glaciers, ice caps and ice sheets to changes in
global sea level on decadal-to-century time scales?

How can we reduce the current uncertainties in these estimates?

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(iii) What changes in frozen ground regimes can be anticipated on decadal-to-
century time scales that would have major socio-economic consequences,
either directly or through feedback on the climate system?
(iv) What will be the annual magnitudes, rates of change, and patterns of seasonal
redistribution in water supplies from snow- and ice-fed rivers under climate
changes?
(v) What will be the nature of changes in sea-ice mass balance in both polar
regions in response to climate change?
(vi) What is the likelihood of abrupt climate changes resulting from regime
changes in ice shelf — ocean and sea ice — ocean interactions that impact the

ocean thermohaline circulation?
(vii) How do we monitor cryospheric components as indicators of change in the
climate system?

Monitoring cryosphere dynamics is a key aspect of high-latitude environmental
studies, especially because of a rather controversial information concerning ice
cover dynamics. It is true, for instance, for ice thickness observations. Holloway
and Sou (2001) have pointed out that

while submarine records had indicated a
stunningly rapid thinning, model results show that the position of submarine
observations was exceptionally biased towards regions of thinning. A conclusion is
that observation to date, along as with much physics as models represent, imply
little or no overall thinning

“

” .

6.2.2 Some Problems of the Permafrost Melting Feedback
to Global Climate Change

Northern ecosystems play signi cant role in global climate change. This fact is

studied by many experts. Particularly, Eastern Siberia refers to these ecosystems. The
territory of Eastern Siberia (7.3 million km 2 ) occupies a significant part of the
Northern Hemisphere and plays an important role for the climate system of the Earth.