Geoscience Reference
In-Depth Information
7 and 57 m of sea level rise, respectively (Heil and Allison 1999). Changes in the
ice mass on land have contributed to recent changes in sea level. On a regional
scale, many glaciers and ice caps play a crucial role in freshwater availability.
Presently, ice permanently covers 10 % of the land surface, of which only a tiny
fraction lies in ice caps and glaciers outside Antarctica and Greenland. Ice also
covers approximately 7 % of the oceans in the annual mean. In midwinter, snow
covers approximately 49 % of the land surface in the Northern Hemisphere (NH).
Frozen ground has the largest area of any component of the cryosphere. All parts of
the cryosphere contribute to short-term climate changes, with permafrost, ice
shelves and ice sheets also contributing to longer-term changes including the ice
age cycles.
As a core project of the World Climate Research Programme, the CliC project
encourages and promotes research into the cryosphere and its interactions as part of
the global climate system. It seeks to focus attention on the most important issues,
encourage communication between researchers with common interests in cryo-
spheric and climate science, promote international co-operation, and highlight the
importance of this
field of science to policy makers, funding agencies, and
the general public. CliC also publicizes signi
findings regarding the role of the
cryosphere in climate, and recommends directions for future study.
CliC aims to improve understanding of the cryosphere and its interactions with
the global climate system, and to enhance the ability to use parts of the cryosphere
for detection of climate change. The scienti
cant
c goals of CliC are to:
improve understanding of the physical processes through which the cryosphere
interacts within the climate system;
improve the representation of cryospheric processes in climate models;
assess and quantify the impacts and consequences of past and future climatic
variability on components of the cryosphere; and
enhance the observation and monitoring of the cryosphere.
To attain these goals, CliC seeks to develop and coordinate national and inter-
national activities aimed at increasing the understanding of four main scienti
c
themes:
1. Interactions between the atmosphere and snow and ice on the land surface.
2. Interactions between glaciers and ice sheets and sea level.
3. Interactions between sea ice, oceans, and the atmosphere.
4. Interactions of the cryosphere with the atmosphere and oceans on a global scale.
CliC encourages the use of observations, process studies and numerical mod-
eling within each of the above topic areas. In addition, CliC promotes the estab-
lishment of new cryospheric monitoring programs. The cryosphere is also
considered as an indicator of climate variability and change. It has been pointed out
in (Allison et al. 2001):
“
Atmosphere-snow/ice-land interactions are concerned with
the role of the terrestrial cryosphere within the climate system and with improved
understanding of the processes, and of observational and predictive capabilities
applicable over a range of time and space scales. Better understanding of the
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