Antarctic Meteorology.

Hokitika Guardian, 17 May 1921, Page 3

Antarctic Meteorology.

THE CAUSE OF THE SCOTT

TRAGEDY. LONDON, March 24. Dr G. C. Sifnpson, who was with the Scott Expedition to the South Pole as meteorologist, and has now been appointed Director of the Meteorological Office in London, has been giving some lectures on his particular subject. At the Royal Institution he addressed a few enthusiasts on the “Meteorology of the Antarctic,” and though his lantern views were mainly scales, and numbers, and temperatures, there was a certain romantic interest attached to those wavy lines made by the recording needles of thermometers and wind gauges. They recalled tlfe terrible sufferings of that intrepid party of explorers who fought so gallantly but failed against the forces of Nature. Dr Simpson, who was at McMurdo Sound during the time the Scott party were making their journey to the Pole and returning, showed the diagrams ot temperatures he had taken at the base during those summer months. But he also showed the diagrams of temperatures taken by the members of the illfated party. “There was something not only abnormal about that summer in the Antarctic,” said the lecturer,, “hut there was something exceedingly abnormal. Scott had started on his journey expecting a wind behind him to help him to the Pole. He had expected a temperature of about minus lOdeg Fahrenheit (or 42deg below freezing point), but what they had to endure was, at the end of February, minus 30deg, and at the end of March minus 40deg (or 72deg below freezing point). There was no wind in the first place, and to this is very largely due the fact that the temperature experienced throughout was 20deg below normal. There is no doubt this contributed very largely to the disaster?*’ As a result of the experiments made at McMurdo Sound, it was found by means of balloons that in summer the temperature gradually and consistently decreased from the ground * upwards, just ns it does in the tropics or in any temperate climate. In winter, however, the ground temperature might he minus 40, but 700 metres in the air it was higher by 20deg. From that point upwards it gradually fell. Tins was owing to the fact that the heavy cold layer of air settled on the ground. 'With the coming of a strong wind or blizzard this layer would he swept away and the ground temperature would rise suddenly as much as 20deg. Although it was summer when Scott and his party were coming away from the Pole, it was sufficiently late for the entire ah. seneo of wind to have the disastrous effect of keeping the temperature 20deg_ below what they might have expected bad the air been in motion.

Dr Simpson showed how the temperature. ranged in winter from north to south on a given longitude. Above the open sea, which acted as a reservoir for the heat, the temperature might ho 30deg (or only -Meg below freezing point). M hen they came to the broken ice it had fallen as as from 10 to 20dog. Over the solid ice it was at zero (or 32deg below freezing point), but immediately they stepped from the ice over the sound on to the Barrier the temperature fell suddenly lOdeg, gradually falling lower as they approached the Pole.

The. lecturer had something to say on the vagaries of the blizzards. In the first place, they are seldom consistent, and from the diagrams shown they varied in speed tram 12 miles one minute to 50 miles the next. But the strangest feature of these Antarctic winds is that they may be blowing at JO or 40 miles an hour, and suddenly there is a* dead calm, lasting perhaps for ten minutes. Then they start again in the same direction, at exactly the same speed as they ceased ten minutes before. The reason for these sudden cessations was answered by the thermometers. As soon as the "inti ceased the temperature would fall as much as 20deg in a minute or less. What had really happened was that a cold layer of air had forced its way to the ground, and the wind, without alteration in itfi speed, had been pushed up to greater heights, just as a large smooth stone thrown into a swiftlymoving stream, would force the water over it.