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(b)
(a)
8.0
7. 5
7. 0
6.5
6.0
5.5
1. 2
8.0
1. 2
7. 5
7. 0
6.5
6.0
5.5
lce salinity 20‰
lce salinity 10‰
1. 0
1. 0
0.8
Permittivity
0.8
Permittivity
Loss
Loss
0.6
0.6
5.0
4.5
4.0
3.5
3.0
-30
5.0
4.5
4.0
3.5
3.0
-30
0.4
0.4
0.2
0.2
0.0
0.0
-26
-22
-18 14
-10
-6
-2
-26
-22
-18
Temperature (°C)
-14
-10
-6
-2
Temperature (°C)
(c)
60
72
Brine salinity 80‰
50
67
62
40
57
30
52
Permittivity
Loss
20
47
10
42
-30
-26
-22
-18 14
-10
-6
-2
Temperature (°C)
Figure 3.32 Temperature dependence of (a) sea ice permittivity and (b) loss for ice salinity 10‰ and 20‰,
respectively; and (c) brine permittivity and loss. Ice density is assumed to be 0.9 g/cm 3 . Permittivity and loss are
calculated for the microwave C‐band [ Shokr and Sinha, 1995].
ice have diameters larger than 0.5 cm [ Shokr and Sinha,
1994], which represents 0.1 of the incident wavelength.
Assessment of the model based on comparison against
field measurements of the complex dielectric constant is
introduced in the following section.
from the end of the inner conductor and bridges into the
end of the outer conductor, forming a nonpropagating
hemispheric‐shaped field whose diameter is approxi-
mately 1.9 cm (Figure  3.33). The discontinuity of the
impedance between the two conductors, caused by the
ice dielectric, leads to reflection of the traveling electro-
magnetic waves at the interface. The reflection coeffi-
cient is measured in terms of magnitude and phase, then
converted into the real and imaginary parts of the com-
plex dielectric constant. The measurements are normal-
ized with respect to the permittivity of the air, which is
measured by pointing the probe tip into the air prior to
bringing it in contact with ice. A full description of the
instrument and the equations to retrieve the complex
dielectric constant from the measured reflection coeffi-
cient are presented in Brundfeldt [1987]. Evaluation of
the instruments' accuracy is established in Jackson [1990]
by using an L‐band probe against 10 different hydrocar-
bon liquids and concluded that permittivity could be
measured at 3% accuracy, while loss was overestimated
by about 15%. It should be noted, however, that the die-
lectric loss is too low to be measured accurately.
3.6.3. Field Measurements of Dielectric Constant
The dielectric constant of FY and MY ice in the
microwave C‐band was measured during the first 3 weeks
of May 1993 and 1995 within the Seasonal Ice
Monitoring and Modeling Site (SIMMS) program in
Resolute Passage, Nunavut, Canada. A description of
the program is presented in LeDrew and Barber [1994].
The instrumentation, technique, and results are pre-
sented in Shokr [1998]. The dielectric constant was meas-
ured using a portable dielectric probe (PDP), consisting
of an open‐ended coaxial cable whose 5 cm diameter tip
is brought in contact with the target dielectric (i.e., sea
ice). This concept is introduced in Stuchly et al. [1982] .
The inner cable is made of brass and the outer is stain-
less steel. During operation, an electric field emerges
 
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