Freezing of Lakes - Freezing of Lakes and the Evolution of their Ice Cover - page 50

primarily controlled by the air temperature and snowfall time history. The general trend
towards warmer winters in ice phenology may thus not be easy to detect in the ice
thickness data (e.g., Lepp 1985; Jevrejeva et al. 2004). Evolution of ice

coverage is related to ice thickness in that thicker ice has more lateral strength and a thick
enough ice cover does not break any more before the melting phase.
The severity of winters can be quanti

ä ranta and Sein ä

ed with the maximum annual ice thickness.In
large lakes, the period of lateral ice growth may be long, and therefore the quantity ice
coverage, equal to the ice area divided by the total lake area, is another characteristic of
the severity of the ice season. Example in Lake Ladoga the probability of complete ice
coverage is about 50 %, although ice forms in the lake every year (Prokacheva and
Borodulin 1985; Karetnikov and Naumenko 2008, 2011) (Fig. 2.19 ).