12 October, 1997

12 October 97

REGIONAL WEATHER SUMMARY....Extensive cloudiness is moving

across the Ross Ice Shelf. This situation is driven by a ridge moving across Byrd Land.

TODAY...Cloudy with snow and blowing snow.

Visibility: 1/2 to 2 miles in snow/blowing snow reducing less than 1/4 mile at times, especially during the morning.

Wind: Southeast 18-25 knots gusting to 40 knots at times.

High -11C/+12F. Lowest Windchill -34C/-29

TONIGHT...Cloudy with periods of light snow and blowing snow. Visibility: 1/2 to 2 miles in snow/blowing snow.

Wind: Southeast 18-25 knots gusting to 40 knots decreasing 15-20 knots gusting to 30 knots by midnight.

Low -18C/+00F. Lowest Windchill -45C/-48F

MONDAY...Cloudy with occasional snow and drifting snow.

Visibility: 1 to 3 miles in snow/drifting snow, becoming unrestricted reducing 1 to 3 in snow by noon.

Wind: Southeast 15-20 knots gusting to 30 knots, decreasing 12-18 knots gusting to 25 knots by late morning.

High -09C/+16F. Lowest Windchill -29C/-20


High Today -13 Low Tonight -20.

YESTERDAY'S EXTREMES - 11 October, 1997

Maximum Temperature: -07C/+19F

Minimum Temperature: -19C/+09F

Peak Wind: 55 KNOTS

Lowest wind chill: -39C/-38F

The dive trip to Cape Evans was canceled. The forecast above was updated and McMurdo has been under Condition Two weather all day. The conditions on the ice are Condition One. I grabbed the information below from the McMurdo intranet. It explains the various types of weather conditions which govern life at McMurdo Station.

Condition I

Sustained winds exceed 55 knots

Wind chill lower then -100 deg F.

Visibility less then 100 feet.

All persons shall remain inside during Weather Condition One. All vehicles on the road report your position to the firehouse dispatcher.

Condition II

Sustained winds 48 to 55 knots.

Wind chill -75 deg F to -100 deg F.

Visibility 100 feet to 1/4 mile.

All travelers (to this location/between these areas) will be conducted in radio equipped vehicles and all vehicles shall check in and out with the fire house dispatcher.

Condition III

Winds less then 48 knots.

Wind chill greater then -75 deg F.

Visibility greater then 1/4 mile

Normal operating conditions

I have been told that this storm is actually the one that was expected on 10 October and was responsible for the cancellation of Dr. Manahan's flight. Apparently the storm took a different path and arrived today instead.

The water in the large 200 liter culture tanks had to be changed today. It's quite a time consuming job. All the seawater must be siphoned off and the microscopic embryos collected in a fine mesh filter. While the tanks are being cleaned and filled samples of the animals are taken, enumerated, and checked for their general condition. This operation takes about 4-5 hours and must be done every 4 days. Soon these animals will begin to be fed algae. When this begins the water-changing operation is expected to take an entire day. This is because the algae are not native to Antarctica therefore the water cannot go into the sewer system. The used water must be collected and placed into containers for special disposal. I discussed waste management at McMurdo in the 7 October journal entry.

Things to ponder:

1. Why do you think scientists must be so concerned with dumping non-Antarctic algae into McMurdo Sound?

2. Many species you are familiar with are not native species, but were introduced by man. The Zebra Mussel is a species recently introduced to the Great Lakes. Find information concerning the introduction of the Zebra Mussel into the Great Lakes ecosystem. What are the consequences for native species. What has been the impact for humans?

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