Future of Frozen Lakes - Freezing of Lakes and the Evolution of their Ice Cover - page 271

paper on lake ice]. Ice engineering aspects are covered in Ashton (1986) and Palmer and
Croasdale (2012). More recent material is given in the article collections of polar lakes
(Vincent and Laybourn-Parry 2008), limnology by George (2009), and in the reviews of
the physics (Kirillin et al. 2012) and fish (Shuter et al. 2012) of frozen lakes.

The Chap. 1 introduces the topic with a brief historical overview. Chapter 2 presents
lakes, their classi

cation, and the zones of ice-covered lakes. Ice formation and the
structure and properties of lake ice are treated in Chap. 3 , with ice impurities and ice mass
balance. Chapter 4 contains lake ice thermodynamics from the freezing of lakes to ice
melting, with thermodynamic models included. Lake ice mechanics is the topic of Chap. 5
including engineering questions such as ice forces and bearing capacity of ice. A section is
included on drift ice in large lakes. Glaciers and pro-glacial lakes are treated in Chap. 6 .
Quite exotic lakes are introduced, in particular lakes at the top and bottom of glaciers and
ice sheets. Chapter 7 focuses on the water body beneath lake ice cover with water balance,
strati cation, and circulation. Applications are treated in Chap. 8 , considering the ecology

of lake water bodies with limitations brought by the ice and life inside the ice cover also
discussed. Environmental and practical questions are treated as well as the impact of
climate change on lake ice seasons. Final closing words are written in Chap. 9 , and the list
of references follow in chapter backmatter. Study problems with solutions are given as
examples in the text. Useful constants and formulae have been collected in an Annex.

9.2 Science and Technology Needs

Scienti c research on lake ice was commenced in the 1800s, and at the same time lake ice

monitoring was commenced in northern Europe. Ice engineering problems were included
in research from the late 1800s, concerning shipping, ice forces on structures, and the
bearing capacity of ice. Also from the early stage of limnology the ecology of frozen lakes
has gained attention, especially in the Central Europe. In large lakes the ice may break and
drift considerable distances which in uences on the evolution of the winter conditions in

lakes and utilization of the lakes (Fig. 9.2 ). In all, the research of ice-covered lakes turned
out to be for long, until about 1970s, scattered and occasional. Thereafter, more effort was
put on polar lakes when the access to reach them was better and measurement techniques
were feasible.
The leading topics are now the impact of climate change on lakes and the ecology of
freezing lakes. Also together with free access high or moderate resolution satellite
imagery, such as Aqua/Terra and Envisat, monitoring of lake ice cover has expanded to
medium-size lakes.
The annual ice cycle depends on the atmospheric mass and heat

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fluxes and is partic-
ularly sensitive to air temperature and snowfall. Furthermore, the sensitivity of modelled
thickness increase is in general inversely proportional to the thickness. Therefore when the
ice is thin we need a more sophisticated model to simulate the growth of ice. The
connection between ice thickness and snow accumulation is quite complicated since the

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