7.5 Surface Gravity Wave Interaction with Elastic Ice Floes
345
IRI a)
IRI
0.6
b)
0.4
0
0.2 ~ ~ ~ lA
~ ~.
0
100 200 300 400 x,m
100 200 300 400 x,m
IRI c)
0.6
0.4
0.2
0
100
200
300 400 x,m
Fig. 7.10. Reflection coefficient IRI vs distance between two (a), three (b) and four
(c) ice plates for wavelength .A = 100m and ice thickness h = 1m. a: continuous
curve - two plates 100 m in length, broken curve - plates 100 and 150 m in length,
dotted line - plates 100 and 175 m in length
maximum reflection coefficient and the distance between resonance points
are increased. The maximum reflection coefficient and the distance between
resonance points are decreased in the presence of internal compression in ice
cover and, consequently, increased in the case of the development of internal
tension.
The reflectance of a system of several ice plates may be less than that of
each plate separately. It may reach zero for a system of plates with identical
length. The dependence of the absolute value of the reflection coefficient on
the inter-plate distance has a period equal to a half-length of the wave in
open water.
There is a filtering effect of the ice floes on the surface wave spectrum:
high-frequency components are reflected by the ice floe much more strongly
than low-frequency components. But due to the presence of resonance points,
local maxima may appear in the spectrum, including its high-frequency range.
345
IRI a)
IRI
0.6
b)
0.4
0
0.2 ~ ~ ~ lA
~ ~.
0
100 200 300 400 x,m
100 200 300 400 x,m
IRI c)
0.6
0.4
0.2
0
100
200
300 400 x,m
Fig. 7.10. Reflection coefficient IRI vs distance between two (a), three (b) and four
(c) ice plates for wavelength .A = 100m and ice thickness h = 1m. a: continuous
curve - two plates 100 m in length, broken curve - plates 100 and 150 m in length,
dotted line - plates 100 and 175 m in length
maximum reflection coefficient and the distance between resonance points
are increased. The maximum reflection coefficient and the distance between
resonance points are decreased in the presence of internal compression in ice
cover and, consequently, increased in the case of the development of internal
tension.
The reflectance of a system of several ice plates may be less than that of
each plate separately. It may reach zero for a system of plates with identical
length. The dependence of the absolute value of the reflection coefficient on
the inter-plate distance has a period equal to a half-length of the wave in
open water.
There is a filtering effect of the ice floes on the surface wave spectrum:
high-frequency components are reflected by the ice floe much more strongly
than low-frequency components. But due to the presence of resonance points,
local maxima may appear in the spectrum, including its high-frequency range.