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Polar Mail from the Oden
Letters: July 5
Question:
What conditions are required to lower a submersible to the arctic seabed? Is the difference in temperature between the bottom of the Arctic Ocean and the other Oceans significant?
— Thank you, and best of luck! Sincerely, Xuan Yue
Answer:
Dear Xuan Yue,
The difference in temperature between the bottom of the Arctic and the
world's other oceans is not really
significant for our vehicle operations. However, when we are on the
icebreaker there are big differences between
how we would work in the Arctic versus the rest of the oceans. The
primary difference is that it can get so cold
that our connectors that we use to plug different sensors into the
vehicle can get so cold that they become brittle. If it
does get that cold we are very careful about heating these connectors
(with a hair-dryer!) before we plug and unplug them.
—Hanumant Singh
The temperature at the bottom of the Arctic does not differ too much from other oceans. The density of seawater depends on temperature, salinity and its pressure (depth). Some oceans have slightly different salinity and temperature but the density is quite similar.
The Arctic and other polar seas have the peculiar structure of having cold surface waters (-2C) lying over warmer waters below, which in turn are above the colder bottom waters, which in the Arctic, are about -0.9C.
—Peter Winsor