METEOROLOGY
APPENDIX  I
South! by Sir Ernest Shackleton

The meteorological results of the Expedition, when properly worked out and correlated with those from other stations in the southern hemisphere, will be extremely valuable, both for their bearing on the science of meteorology in general, and for their practical and economic applications.

South America is, perhaps, more intimately concerned than any other country, but Australia, New Zealand, and South Africa are all affected by the weather conditions of the Antarctic. Researches are now being carried on which tend to show that the meteorology of the two hemispheres is more interdependent than was hitherto believed, so that a meteorological disturbance in one part of the world makes its presence felt, more or less remotely perhaps, all over the world.

It is evident, therefore, that a complete knowledge of the weather conditions in any part of the world, which it is understood carries with it the ability to make correct forecasts, can never be obtained unless the weather conditions in every other part are known. This makes the need for purely scientific Polar Expeditions so imperative, since our present knowledge of Arctic and Antarctic meteorology is very meagre, and to a certain extent unsystematic. What is wanted is a chain of observing stations well equipped with instruments and trained observers stretching across the Antarctic Continent. A series of exploring ships could supplement these observations with others made by them while cruising in the Antarctic Seas. It would pay to do this, even for the benefit accruing to farmers, sailors, and others who are so dependent on the weather.

As an instance of the value of a knowledge of Antarctic weather conditions, it may be mentioned that, as the result of observations and researches carried out at the South Orkneys, a group of sub-Antarctic islands at the entrance to the Weddell Sea, it has been found that a cold winter in that sea is a sure precursor of a drought over the maize and cereal bearing area of Argentina three and a half years later. To the farmers, the value of this knowledge so far in advance is enormous, and since England has some three hundred million pounds sterling invested in Argentine interests, Antarctic Expeditions have proved, and will prove, their worth even from a purely commercial point of view.

I have given just this one instance to satisfy those who question the utility of Polar Expeditions, but many more could be cited.

As soon as it was apparent that no landing could be made, and that we should have to spend a winter in the ship drifting round with the pack, instruments were set up and observations taken just as if we had been ashore.

A meteorological screen or box was erected on a platform over the stern, right away from the living quarters, and in it were placed the maximum and minimum thermometers, the recording barograph, and thermograph, an instrument which writes every variation of the temperature and pressure on a sheet of paper on a revolving drum, and the standard thermometer, a very carefully manufactured thermometer, with all its errors determined and tabulated. The other thermometers were all checked from this one. On top of the screen a Robinson's anemometer was screwed. This consisted of an upright rod, to the top of which were pivoted four arms free to revolve in a plane at right angles to it. At the end of these arms hemispherical cups were screwed. These were caught by the wind and the arms revolved at a speed varying with the force of the wind. The speed of the wind could be read off on a dial below the arms.

In addition there was an instrument called a Dines anemometer which supplied interesting tracings of the force, duration, and direction of the wind. There was an added advantage in the fact that the drum on which these results were recorded was comfortably housed down below, so that one could sit in a comparatively warm room and follow all the varying phases of the blizzard which was raging without. The barometer used was of the Kew Standard pattern. When the ship was crushed, all the monthly records were saved, but the detailed tracings, which had been packed up in the hold, were lost. Though interesting they were not really essential. Continuous observations were made during the long drift on the floe and while on Elephant Island the temperature was taken at midday each day as long as the thermometers lasted. The mortality amongst these instruments, especially those which were tied to string and swung round, was very high.

A few extracts from the observations taken during 1915, the series for that year being practically complete, may be of interest. January was dull and overcast, only 7 per cent. of the observations recording a clear blue sky, 71 per cent. being completely overcast.

The percentage of clear sky increased steadily up till June and July, these months showing respectively 42 per cent. and 45.7 per cent. In August 40 per cent. of the observations were clear sky, while September showed a sudden drop to 27 per cent. October weather was much the same, and November was practically overcast the whole time, clear sky showing at only 8 per cent. of the observations. In December the sky was completely overcast for nearly 90 per cent. of the time.

Temperatures on the whole were fairly high, though a sudden unexpected drop in February, after a series of heavy north-easterly gales, caused the ship to be frozen in, and effectually put an end to any hopes of landing that year. The lowest temperature experienced was in July, when , 35° Fahr., i.e. 67° below freezing, was reached. Fortunately, as the sea was one mass of consolidated pack, the air was dry, and many days of fine bright sunshine occurred. Later on, as the pack drifted northwards and broke up, wide lanes of water were formed, causing fogs and mist and dull overcast weather generally. In short, it may be said that in the Weddell Sea the best weather comes in winter. Unfortunately during that season the sun also disappears, so that one cannot enjoy it as much as one would like.

As a rule, too, southerly winds brought fine clear weather, with marked fall in the temperature, and those from the north were accompanied by mist, fog, and overcast skies, with comparatively high temperatures. In the Antarctic a temperature of 30°, i.e. 2° below freezing, is considered unbearably hot.

The greatest difficulty that was experienced was due to the accumulation of rime on the instruments. In low temperatures everything became covered with ice-crystals, deposited from the air, which eventually grew into huge blocks. Sometimes these blocks became dislodged and fell, making it dangerous to walk along the decks. The rime collected on the thermometers, the glass bowl of the sunshine recorder, and the bearings of the anemometer, necessitating the frequent use of a brush to remove it, and sometimes effectively preventing the instruments from recording at all.

One of our worst blizzards occurred on August 1, 1915, which was, for the ship, the beginning of the end. It lasted for four days, with cloudy and overcast weather for the three following days, and from that time onwards we enjoyed very little sun.

The weather that we experienced on Elephant Island can only be described as appalling. Situated as we were at the mouth of a gully, down which a huge glacier was slowly moving, with the open sea in front and to the left, and towering, snow-covered mountains on our right, the air was hardly ever free from snowdrift, and the winds increased to terrific violence through being forced over the glacier and through the narrow gully. Huge blocks of ice were hurled about like pebbles, and cases of clothing and cooking utensils were whisked out of our hands and carried away to sea. For the first fortnight after our landing there, the gale blew, at times, at over one hundred miles an hour. Fortunately it never again quite reached that intensity, but on several occasions violent squalls made us very fearful for the safety of our hut. The island was almost continuously covered with a pall of fog and snow, clear weather obtaining occasionally when pack-ice surrounded us. Fortunately a series of south-westerly gales had blown all the ice away to the north-east two days before the rescue ship arrived, leaving a comparatively clear sea for her to approach the island.

Being one solitary moving station in the vast expanse of the Weddell Sea, with no knowledge of what was happening anywhere around us, forecasting was very difficult and at times impossible.

Great assistance in this direction was afforded by copies of Mr. R. C. Mossmann's researches and papers on Antarctic meteorology, which he kindly supplied to us.

I have tried to make this very brief account of the meteorological side of the Expedition rather more "popular" than scientific, since the publication and scientific discussion of the observations will be carried out elsewhere; but if, while showing the difficulties under which we had to work, it emphasizes the value of Antarctic Expeditions from a purely utilitarian point of view, and the need for further continuous research into the conditions obtaining in the immediate neighbourhood of the Pole, it will have achieved its object.

APPENDIX  I:
PHYSICS