5 November, 1997

5 November 97

0500L SEVERE WEATHER CONDITION

Condition II McMurdo Station

Condition I all other locations.

REGIONAL WEATHER SUMMARY...A low pressure system over the southern Ross sea is moving slowly east-northeast providing a southerly flow over the Mcmurdo area.

TODAY..Cloudy with snow and blowing snow.

Visibility: 1/2 to 3 miles in snow and blowing snow.

Wind (knots): Southeast 15 to 25 occasionally gusting to 40 knots. High -08C/+18F. Lowest Wind-chill -29C/-21F.

TONIGHT...Cloudy with periods of snow and blowing snow becoming mostly cloudy.

Visibility: 2 to 4 miles in blowing snow becoming unrestricted. Wind (knots): Southeast 15 to 25 shifting to northeast 12 to 18 knots. Temperature -13C/+09F. Lowest Wind-chill -37C/-34F.

THURSDAY...Mostly cloudy.

Visibility: Unrestricted.

Wind (knots): Northeast 15 gusting to 25.

High -12C/+10F. Lowest Wind-chill -35C/-32F.

SCOTT BASE 24HR TEMPERATURE FORECAST

High: -12C. Low: -16C

ASTRONOMICAL DATA

Next sunrise in February, 1998

YESTERDAY'S EXTREMES: 03 November, 1997

Maximum Temperature: -08C/+18F

Minimum Temperature: -19C/-02 F

Peak Wind: 49 Knots

Lowest wind chill: -43C/-46F

When I turned in I had it in my mind that I would get a goon night's sleep and things would be fine in the morning. Was I ever wrong! The storm continued all night long and was much worse the next morning. When I awoke I found that the entire rear section of my tent was completely burried. The snow had drifted to the top of the snow wall we had built and deposited on the lee side where my tent was located. When I went outside I found that it was impossible to see the other tents no more than 30 feet away and the wind was howling furiously.

The common experience was that we were warm and cozy in our sleeping bags but our frozen clothes had partially thawed and were wet. I sounds odd but vapor from your breathing is a significant problem since it freezes almost immediately. My neck gaiter had acquired several successive layers of ice and stood up by itself when removed. Breath freezes on the inside of the tent and then rains down as ice when the wind blows. This then melts on your sleeping bag turning it soggy.

We stood around in the blizzard and compared notes about how well we survived the night and contemplated the best way to break camp. A fresh team of instructors had been sent out to pick us up but was having great difficulty reaching us. It was impossible to see and they were using GPS and radar to find us. We were unable to hear or see them approaching and didn't notice them until they were actually upon us.

The decision was made to load our personal and sleeping gear and not attempt to take down the tents. They wanted to get us back to town while they felt there was a reasonable chance to avoid spending another day (or more) in the field camp. The remainder of the instruction was to be classroom instruction and this was done at the Field Safety Training building in McMurdo.

It was 1:30 PM when we began our last instruction using long range and line of sight radios. Afterwards there was a short graduation ceremony and we received special patches identifying us as course graduates. We were told that this was the first time a class had not been required to take down their tents and that we all could be proud of our performance.

That evening Dr. Art Devries presented the science lecture concerning his recent research with Antarctic fish. It was very interesting from an evolutionary point of view and I left with lots of ideas for integrating much of it into my teaching.

Dr. Devries has spent most of his career studying why Antarctic fish don't freeze when the water they live in is below freezing. It turns out they produce special proteins which prevent the formation of ice crystals. They have been termed AFGP, or antifreeze glycoproteins. It seems that their origin can be traced to a modification of the trypsinogen gene which produces the digestive enzyme, trypsinogen. Trypsinogen, like AFGP, is secreted into the digestive tract. This is one location an Antarctic fish is likely to encounter ice crystals by drinking the freezing water.

Things to ponder:

The Antarctic Cod is not a close relative of the Arctic Cod. It has been found that both produce AFGP although the Antarctic fish produces it all the time while the northern fish only produces it seasonally. The strange thing is that it has been shown that the Arctic fish does not produce AFGP which evolved from the trypsinogen gene. Its AFGP gene evolved completely independently. Evolution, therefore, created the same AFGP gene twice by using two different molecular ancestors. This is called convergent evolution.

1. Research this topic and make a list of other examples of convergent evolution.

2. Where do new genes come from? Without new genes evolution would not be possible.