Sunday, December 5, 1999

Cold Hard Facts

Published in the Antarctic Sun

Does the water in the sink, toilet or tub spin down the drain in opposite directions in the Northern and Southern Hemispheres? If so, why?

You probably learned about the Coriolis Effect in high school or college science classes. This effect, caused by the rotation of the Earth, does mean that weather patterns and ocean currents spin counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.

But this effect is fairly small, and does not make much impact on such small amounts of water as those in a sink or toilet. Amounts of water along the lines of a swimming pool, however, do tend to exhibit the results of the Coriolis Effect, but only when they are drained relatively slowly and
when the water is very still prior to draining.

In reality, sinks and toilets drain in either direction in both hemispheres, depending largely on the designs of the basin and direction of flow of the water toward the drain.

What’s the coldest temperature recorded in Antarctica? The hottest? The highest wind speed?

Here are those statistics according to the website glacier.rice.edu:
Coldest: -129 F at Vostok on the polar plateau, on July 21, 1983. This is also the world’s low-temperature record.
Warmest: 59 F at Vanda Station, Scott Coast, on January 5, 1974.
Convergent katabatic winds flowing from the East Antarctic Ice Sheet make the Cape Denison-
Commonwealth Bay region of Adelie Land the windiest spot on Earth. The mean annual wind speed is 50 miles per hour and maximum measured wind velocities exceed almost 200 mph.