16
First-Year Ice
Multiyear Ice
S B = 14.237 0.194TF
12
8
S B = 7.879 0.016TF
4
0
100
200
300
400
TF, Floe Thickness (cm)
k
5/4
Figure 6. Sea-ice bulk salinity vs. floe thickness as reported by Cox and Weeks
(1974).
20
rapid decrease in bulk salinity as the ice
sheet grew to about 0.5 m thick and a
gradual decrease in bulk salinity there-
15
after.
Other early reports also confirm that
this bulk salinity vs. floe thickness trend
applies to Antarctic sea ice. Fedotov
10
(1973) measured the bulk salinity of the
fast ice in Alasheev Bight during the
growth period. His results are presented
in Figure 8. The bulk salinity was found
5
to be about 25‰ in the 5-cm-thick ice
but dropped rapidly to about 7.5‰ when
Date of Determination
1 Jan
1 Feb
1 Mar
1 Apr
1 May
the ice was 0.5 m thick. At the end of the
0
measurement period (about 170 days),
24
54
85
90
95
Avg. Ice Thickness (cm)
the ice was 150 cm thick and the bulk
salinity had decreased to about 5‰.
Figure 7. Sea-ice bulk salinity vs. ice sheet thickness and growth
Doronin and Kheisin (1975) presented
time (after Weeks and Lee 1958).
results for the bulk salinity of Antarctic
fast sea ice during the growth and melt periods
In the mid-1950s, Weeks and Lee (1958) pub-
(Fig. 9). This figure again shows a rapid decrease
lished their observations on the bulk salinity of
in the bulk salinity during the first growth month,
an ice sheet vs. ice thickness and growth time
followed by a gradual decrease until the onset of
(Fig. 7). The abrupt step in the curve through the
the melt season in October. At this time another
data occurred as a result of a flooding event dur-
rapid decrease in the bulk salinity began, which
ing which seawater infiltrated the snow cover.
ended in December. The ice sheet's bulk salinity
Had this not occurred, one could visualize that
had by then decreased to about 2‰, a value rep-
the trend of the curve before the step would have
resentative of Arctic multiyear sea ice of similar
continued to decrease to a salinity of about 5‰
thickness.
by May. In any event, the data clearly reveal a
5
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