Geology Reference
In-Depth Information
(a)
(b)
Figure 3.29
Calculated (a) permittivity and (b) loss of first‐year ice in microwave C‐band versus ice temperature and
salinity for a constant density of 900 kg/m
3
, assuming randomly oriented brine inclusions [
Shokr and Sinha,
1995].
Figure 3.30
Calculated permittivity and loss of first‐year ice in microwave C‐band versus ice temperature and
salinity for a constant density of 900 kg/m
3
, assuming oriented needle brine inclusions [
Shokr and Sinha,
1995].
perpendicular to the electric field. While permittivity is
higher by at most a factor of 2, loss is higher by almost
an order of magnitude. This demonstrates the sensitivity
of the loss to the anisotropic shape of brine pockets.
The rapid increase in permittivity and loss at tempera-
tures above −8.2 °C can be explained in terms of the tem-
perature dependence of volume fractions of the sea ice
composition (Figure 3.18). For an ice density of 0.9 g/cm
