Introduction - Freezing of Lakes and the Evolution of their Ice Cover - page 3

conditions, ' rikko ' = broken); in Russian language there is a corresponding word

pac п y тиц a (rasputica) for land crossing. One of the first records of lake ice events is ' The

battle on the ice ' , a winter clash between the forces of the Norwegian king Á li and the

Swedish king A nern in Sweden, about year 530 AD (Osborn

and Mitchell 2007). The chart and booklet of Olaus Magnus Gothus (1539) also showed
drawings of crossing over ice-covered lakes by skis, skates and horses in the Middle Ages.
In wood industry logs have been stored in winter on ice to be dragged or

ð als on the ice of Lake V ä

flown along
streams to factories after ice melt. Until about mid-20th century, when refrigerators were
not common, the cold content of lake ice was utilized. Ice blocks were cut in winter,
stored under a sawdust cover to protect against melting, and used as a cooler for foods in
summer. Openings were sawed into the lake ice cover for household water and for
washing clothes at the site. For ice-covered lakes, special techniques were developed for
domestic and commercial winter

fl

fishing.

c research on lake ice was commenced in the 1800s along with the birth of
physical limnology and lake hydrology. Scientists in the European Alpine countries have
played a strong role in physical limnology, and therefore it is natural that lake ice has been
considered as an important topic from the beginning (e.g., G

Scienti

tzinger 1909; Verescagin
1925). Lake ice monitoring was also commenced in northern Europe in the 1800s (Si-
mojoki 1978). The lake ice season modi

ö

es the hydrological year in cold regions by its

in uence on the annual distribution of runoff and by the problems caused by ice to the

management of water resources. Ice engineering problems were included in scienti

fl

c
research from the late 1800s (Barnes 1928), concerning shipping, ice forces on structures,
and the bearing capacity of ice.
Lake ice phenology 2 has been a major topic, since ice seasons show large variability,
which is a critical issue to the local population (Simojoki 1940). Collection of ice phe-
nology time series of inland waters was commenced in the 1800s (H ä llstr ö m 1839;

Lev nen 1894), and now they are of great importance in the research of climate history.

Long time series are available, e.g., from 1443 for Lake Suwa, Japan (Arakawa 1954),
from 1833 for Lake Kallavesi, Finland (Simojoki 1959), and from 1850 for Lake Men-
dota, Wisconsin (Wing 1943). Records of lake ice in Central Europe have been used to
examine the occurrence of extreme cold winters (Maurer 1924). Winter temperature
conditions in lakes were also investigated in the early lake research (Hom

ä

n 1903).
Ecology of frozen lakes gained more attention only later (see, e.g., Greenbank 1945;
Hutchinson 1957; Vanderploeg et al. 1992). In all, the research of ice-covered lakes turned
out to be for long, until about 1970s, scattered and occasional. The annual cycle of lakes
was taken into the topics of the International Hydrological Decade 1965

é

1974 with ice
season then considered in cold regions (e.g., Falkenmark 1973). Thereafter, more effort
was made on polar lakes as the access to reach them was better and measurement tech-
niques had become feasible.

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2 Phenology refers to studies of dates of recurring phenomena; it originates from the Greek word
φʱʯʽˉ (phain ō ), ' to make appear ' .