19 October, 1996

Subject: Re: Journal 19 October 1996

Live from the Polar Duke in the Gerlache Strait

Location: 64.15S X 61.51W Wind Speed: 4.2 m/sec

Boat Speed: 0.0 knots Wind Direction: 301 degrees

Boat Heading: 340 degrees Barometer: 995.06 mb

Humidity: 63% Air Temp.: -2.7 C

Salinity: 33.7 0/00 Water Temp.: -1.4 C

General Weather Conditions: Absolutely beautiful day. At home I would call this the perfect winter day. Warm, sunny and clear. Barometer is high again.

Another diel today, made bearable by the beautiful weather. It's amazing how the weather can have such mood altering affects.

The temperatures have not been as cold as I expected. Our lowest temperature so far has been -8.8 C, which is about 14 degrees F. Fourteen degrees is bearable except if the wind is blowing, which seems to occur with great frequency. At temperatures of -5 to -10 degrees C with a wind speed of 40 knots (a knot is 1.12 miles) exposed flesh freezes!

The localized winds in Antarctica are generated and controlled by the shape of the icecap rather than atmospheric pressure. These winds are called katabatic winds, meaning down flowing. Cold air near the surface of the icecap, behaves somewhat like water seeking it's lowest point, that is, it flows down the icecap toward the coasts. The ice at the South Pole is two miles thick (I was told that they sell t-shirts at the South Pole that say "Ski the South Pole, Six Inches of Powder and Two Miles of Base"). These frequent cold blasts of air form a very shallow layer.

Obviously, the coastal areas feel the full force of the katabatic winds. These winds mainly come from out of the southeast and we have definitly experienced strong katabatic winds. On several occasions, the seas have gone from almost flat calm with less than a puff of wind to full fleged white-caps and swells in a matter of minutes. Apparently, katabatic winds will also help to intensify low pressure generated storms.

The visability, on those rare occasions when the skies are clear, in Antarctica is supurb. The reason why is because there is no dust or smoke in the atmosphere which causes light to refract or bend. Refraction of light causes distortions that reduce visability. The mountains and glaciers appear to be much closer to the ship than they really are. Several times I have made special trips to the bridge to read the charts and determine the actual distance to the familar landmarks that I have been looking at all day.

Thanks for all the questions and mail. I hope to answer them all in the next few days.

Margaret Brumsted

NSF Teacher in Antarctica