Structure and Properties of Lake Ice - Freezing of Lakes and the Evolution of their Ice Cover - page 72

Fig. 3.11 Ice sample analysis for gas bubbles in winter 2008 - 2009. a Gas bubbles in lake ice sheet
(top toward the right) in Hongipao Reservoir, Heilongjiang Province, China (February 9, 2009);
b Bubble size and gas volume as functions of depth From Li et al. (2011)

A quantity proportional to ice volume scales as ( 1 m a ), as does the density (see

Example 3.2), if the in uence of gases can be ignored. A good reference density is for

congelation ice 910 kg m − 3 and for snow-ice 875 kg m − 3 . Many properties of lake ice
depend on areal cross-sections, e.g. ice strength and thermal conductivity; assuming gas
inclusions as randomly spaced spheres, by dimensional analysis it is seen that these
properties would be reduced by a factor of

fl

, where r 1 is a geometrical model
parameter. If the inclusions were long vertical cylinders, the scaling factor would be
1 r 2 m 1 = 2
a

1 r 1 m 2 = 3

a

, where r 2 is another geometrical model parameter (Assur 1958).
In brackish and saline lakes, liquid brine pockets may take a signi

cant portion of the
ice volume. They have been extensively examined for sea ice (Weeks 1998). When saline
water freezes, ice crystals form of water molecules, i.e. freezing tends to separate