Name: Robert
Status: Other
Age: 20s
Location: N/A
Country: N/A
Date: N/A
Question:
I have a question about the artic is it fresh water and if
it isn`t how does the extreme cold manage to freeze the salt water?
Replies:
Robert
The water in the Arctic is salt water, just as
the rest of the ocean is. However, the salt
content may be less than the mid-Atlantic, for
instance. The ice (built up from snowfall,
as well as cold air temperatures) tends to dilute
the salt content slightly as it slowly melts
during warmer weather. Water with salt will
freeze at a lower temperature than the freezing
temperature (0 degrees C, 32 degrees F) of pure
water. The Arctic Ocean temperature is therefore
normally lower than 0 degrees C. Cold air
temperatures during the greater part of the year
keep a large area around the top of the world
permanently frozen.
An interesting twist to this is that the Arctic
ice has thinned significantly in the past 30
years, indicating that the temperature of the ocean
water underneath it has increased slightly
(on average). A monitoring station was put in place
at the North Pole at the beginning of this year
and will be maintained for at least 5 years to try
to determine the cause of the thinning.
Measurements from the most recent submarine mission
under the ice cap (see the National Geographic
web site to find an article on the mission) and a
year-long experiment on the icepack called SHEBA
(sponsored by the Dept. of Energy Atmospheric
Radiation Measurements Program) should add to our
understanding.
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