Geology Reference
In-Depth Information
14
14
(
T
w
-T
a
)=5
(
T
w
-T
a
)=10
(
T
w
-T
a
)=15
Snow thickness = 50 mm
12
12
10
10
8
8
6
6
4
(
T
w
-T
a
)=5
(
T
w
-T
a
)=10
(
T
w
-T
a
)=15
4
2
2
Snow thickness = zero
0
0
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
Freezing degree-days
Freezing degree-days
14
14
Snow thickness = 100 mm
(
T
w
-T
a
)=5
(
T
w
-T
a
)=10
(
T
w
-T
a
)=15
Snow thickness = 150 mm
(
T
w
-T
a
)=5
(
T
w
-T
a
)=10
(
T
w
-T
a
)=15
12
12
10
10
8
8
6
6
4
4
2
2
0
0
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
Freezing degree-days
Freezing degree-days
Figure 2.15
Dependence of ice thickness on freezing degree‐days for different snow thickness and air temperature,
calculated by using equation (2.17).
Table 2.2
Insulating effect of 50 mm of different snow types in
terms of their equivalent insulating effect of sea ice thickness.
and
Iacozza and Barber
[2010]. As a general rule, snow
depth increases on ice that has been formed earlier (since
more time allows more snow to accumulate) or deformed
later (e.g., on rough ice including ridged and ice or rub-
ble fields). Temporal evolution of snow on ice is con-
trolled by the timing of snowfall and wind speed. In the
Arctic region, most of the snowfall takes place in the fall
and spring [
Sturm et al.,
2002]. Strong wind of at least
7.7 m/s is required to redistribute the snow across the ice
surface [
Li and Pomeroy,
1997].
Measurements of snow depth over sea ice are usu-
ally conducted using a point sampling approach. This
approach was adopted in most field studies. A few early
studies include the AIDJEX in the Beaufort Sea [
Cox and
Weeks,
1974
; Martin,
1979], the Eclipse Sound experi-
ments in 1977-1979 [
Sinha and Nakawo
, 1981;
Nakawo
and Sinha
, 1981], the Mould Bay experiment [
Holt and
Digby,
1985; see also Section 5.1], and the MIZEX'84
in Fram Strait [
Tucker et al.,
1987]. It was also used in
a series of experiments on Arctic sea ice, known as Sea
Ice Monitoring and Modeling Site (SIMMS), conducted
between 1990 and 1997 in Resolute Passage, Canadian
eastern Arctic [
Barber et al.,
1992]. Details on temporal
and spatial distribution of snow and ice across the 7.2 km
0.05 m of Various
Snow Types
Equivalent to an
Ice Thickness of:
Fresh soft snow
2.64-3.80 m
Semisettled snow
1.75-1.93 m
Settled snow cover
0.61-0.97 m
Old snow
0.41-0.61 m
Hard packed snow
0.24-0.31 m
Extremely cold snow
0.19-0.24 m
investigations on the characteristics of snow from the
beginning to the end of winter growth season on sea ice
at Eclipse Sound were carried out, primarily, for mode-
ling thermodynamic growth of ice and growth rate
dependence of brine inclusion and microstructural fea-
tures. Mould Bay studies were performed to document
the effect of snow cover on the temporal as well as spatial
variability of ice thickness across the 7.8 km wide bay.
Relatively recent studies that address snow depth and dis-
tribution on sea ice, with no data on ice thickness and
distribution, include
Barber et al.
[1994],
Barber and
Nghiem
[1999],
Haas et al.
[2008],
Nicolaus et al.
[2009],
