Polar Exploration/Chapter 8
CHAPTER VIII
METEOROLOGY
Not the least interesting study of the Polar Regions is from the meteorological aspect, and this seems to be especially so in the case of the Antarctic Regions. It seems extremely likely, if a set of permanent stations were established in the Antarctic Regions, with first-class equipment, thoroughly trained observers and not too few of them, that we might find the key for forecasting the weather not only of the southern hemisphere, but also, at least to some extent, that of the northern hemisphere also. One of the triumphs of the Scottish Expedition (1902–1904) was the meteorological work, and this was due to the fact that the Scotia had on board such an eminent practical meteorologist as Mr. Robert C. Mossman. Mr. Mossman conducted the chief meteorological station in Edinburgh; he had, besides, extensive practical experience of work on the summit of Ben Nevis, and at the head of Glen Nevis. The Glen Nevis station was especially for the study of the Föhn winds. Before Mr. Mossman joined the Scotia, his field work and publications had placed him in the van of European meteorologists. Mr. Mossman was supported by two other trained meteorologists—the author, who had had experience for nearly two years at both high and low level Ben Nevis observatories, and who had been in charge of the summit observatory for more than a year, besides having had previous meteorological training and experience, and Mr. D. W. Wilton, who had also worked as an observer at both Ben Nevis stations, and who had been in charge of a smaller observatory half-way up the Ben for some months.
Thus, not only were there three thoroughly trained meteorologists on board the Scotia, a condition of efficiency not approached by any other Antarctic expedition, but each one of the three had experience of taking observations amid conditions of continual ice and snow. One had had experience of taking meteorological observations during long periods both in the Antarctic and Arctic Regions, and a second had had experience of taking meteorological observations for fifteen months in the Arctic Regions. Besides these three, Captain Robertson had taken meteorological observations in the Arctic and Antarctic Regions during many voyages. These facts are mentioned to emphasize the importance of the Scotia meteorology, which has been enhanced by the fact that the results have been worked up by the man who conducted the work in the field, and who remained in the Antarctic Regions for another year, in the service of the Argentine Republic, after the Scotia had sailed for home.
Mr. Mossman has, since the completion of the Meteorological Reports of the Scotia, rejoined the Meteorological Service of the Argentine Republic, and a special part of his work there is in connection with the working up of the results of the Scotia Bay Station, which that energetic South American Republic has continued to support and direct during the past six years. The results of this work are already being felt. Before the Scotia had left the Antarctic Seas, Mr. Mossman was able to demonstrate meteorologically the existence of the land reported by Johnson and Morrell, extending northward to about latitude 65° S. in longitude 44° W., where both Ross and Crozier reported an "appearance of land," and where Nordenskjold's people on board the Antarctic also had possible "appearance of land." Nordenskjold dismisses the idea of land here because an iceberg was actually mistaken for an island at one time, and because of the depth obtained, viz. 2,031 fathoms. But Nordenskjold, according to his chart, was at least 40 miles farther off the point where Ross and Crozier reported "appearance of land," "land blink," etc. (Preliminary Chart, showing the Track of the "Antarctic" in Antarctica, by Dr. N. Otto G. Nordenskjold and Dr. John Gunnar Andersson: London, 1905). The depth also is quite significant of land in these regions, for the Scotia obtained 1,746 fathoms fifteen miles off Coronation Island, and 2,370 fathoms only sixty miles off Coats Land. Mr. Mossman has pointed out that at Scotia Bay, South Orkneys, "the warmest winds are N.W. and N., and the coldest S. and S.E., there being a difference of 21.7° between the warmest and coldest directions. It is of interest to note the great difference between the temperature of west and south-west winds. On the mean of the seven months the south-west is 16.5° colder than the west, while in June the difference was as much as 22.2° F.
"From these observations it appears probable that there is a mass of land, the northern extremity of which is in lat. 65° S., long. 44° W., both Morrell and Ross having referred to an 'appearance of land' in this region. The circumstance that 'Föhn' winds blow from the west doubtless partly accounts for their relatively high temperature; but there are other reasons, notably the comparatively high barometric pressure experienced with south-west winds, which indicate a local anticyclone in winter such as would form over a land surface."
Since that time, with the additional data furnished by the Scotia Bay Station during eight years, it has become more than ever certain that New South Greenland, as Johnson called it, really exists. The meteorological observations of the Scotia have also helped to prove that Coats Land is part of the Antarctic Continent.
If no other results of the Scotia meteorology than these two had been obtained, it would be acknowledged that those results were very valuable indeed. But Mossman has also found that there is a distinct relationship between the weather in Chile and the weather in the Weddell Sea. This is one of the most valuable economic results of the voyage of the Scotia. I will even venture to predict that the observations carried on at Scotia Bay, along with those in South America and South Africa, will be found most valuable in predicting the condition of the monsoons in India. Should this prove to be the case, it can then be said that the study of meteorology in the Antarctic Regions can be used for the alleviation of human suffering by enabling us to give sufficiently long warning to our fellow citizens of the Indian Empire to prepare for failure of crops, and ward off starvation and ruin.
The meteorological work of the Scotia has alone been mentioned, and that is because it is generally acknowledged that this work conducted by Mossman is the most important of all the meteorological work carried out by any of the Antarctic expeditions. But all the recent Antarctic expeditions have taken very careful series of observations, and these taken along with the Scotia observations form a most valuable addition, not only to our knowledge of Antarctic weather conditions, but to the meteorology of the world. Since the establishment of the Scotia Bay Observatories, the Argentine Republic have set up another station on South Georgia, and have considered setting up yet another on the west coast of Graham Land where De Gerlache and Charcot have done such very excellent meteorological work. Charcot's observations, having been synchronous with those at Scotia Bay and South Georgia, are very important. There is little doubt that more of these permanent stations in other parts of the Antarctic and subantarctic Regions working in conjunction with the two already mentioned and with the observatories not only in South America, but also in conjunction with those in South Africa, Australia, and New Zealand, would be a most valuable form of Antarctic exploration that would greatly increase our knowledge and benefit humanity.
It is not necessary to enlarge on the scientific value of such a network of meteorological stations in the southern hemisphere, where, on account of the huge expanse of ocean, atmospheric conditions are simplified and there are not so many of those disturbing conditions which upset the most careful calculations in the northern hemisphere, where the oceans are of less account, and only serve to separate from one another land masses of varying size and character. If all the surface of the globe were water or land of uniform altitude, meteorology would be simplicity itself, but as it is, it is one of the most complex sciences existing. It is, therefore, very essential to concentrate our energies on those parts of the terrestrial globe where conclusions are most likely to be arrived at concerning the general laws which govern the climate and weather of the world. In the far south the conditions are simpler than in any other part of the world, hence the importance of making a special study of meteorology round about the South Pole.
It is not so easy to place an economic, or even a scientific, value on the meteorological work that has been done in the North Polar Regions. It is very difficult to analyse properly Arctic observations, owing, as before stated, to the more complex distribution of land and water in that region. But there is no doubt that one of the difficulties is the desultory fashion in which meteorological investigation has been carried out in the North Polar Regions, the international co-operation of 1881 and 1882 being the only instance where a systematic attempt was made to study the meteorology of the Arctic Regions as a whole, and even these stations were not in existence for a long enough period. Yet it was largely the study of these records that enabled Nansen to plan his expedition in the Fram, and to venture to boldly thrust his ship into the ice-pack, confident that the drift would carry it right across to the open water at the other side of the Pole. Peary, in his many sledging expeditions from the north coasts of Greenland and Grant Land towards the Pole, found the ice-floes always moving eastward, indicating a drift of the Arctic water in that direction. There is no doubt that a systematic study of the winds of the Arctic and subarctic Regions in relation to their cyclonic and anticyclonic systems is of the utmost importance, as upon these winds depend very largely the direction and flow of Arctic currents and Arctic ice-pack. Given prevailingly north-east winds over Franz Josef Land, even if they are very light, then the polar pack comes driving past that archipelago, not only the north but also the south of it by the straits between it and the north of Novaya Zemlya. Jamming against the east coast of Wilczek Land, and against the north end of Novaya Zemlya, this southern pack sweeps westward across the northern portion of the Barents Sea, and, bringing up against the east coast of Spitsbergen, is forced past South Cape, and, during some summers like that of 1910, round South Cape, filling up Bell Sound and other western fiords in Spitsbergen with ice. On the other hand, if there is a prevalence of south-east winds in the Barents and Greenland seas, this pack is driven back, and the coasts of Spitsbergen, and even the southern shores of Franz Josef Land, are free of ice. This was the case in Franz Josef Land during the summer of 1897, and even during the previous midwinter, when there was open water to within a quarter of a mile of Cape Flora, on the 24th of December, 1896. On the contrary, the wreck of Leigh Smith's yacht, the Eira, off Cape Flora in 1881, was due to a change of balance between the easterly and westerly system of winds, which caused the polar pack rapidly to close in upon the vessel, and crush it against the land floe. Leigh Smith had foreseen this, for he well knew how the movements of the pack depended on the wind, and, had his instructions been carried out, the Eira would not have been lost.
That part of the current which passes to the north of Franz Josef Land from east to west, and which is largely dependent on the wind, was the current that carried the Fram across the Polar Basin from the New Siberian Islands to the north-west of Spitsbergen. Now these easterly and north-easterly winds that have been spoken of are the outflowing winds of the Eurasian anticyclone, as are the north-west winds blowing across the Himalayas and continuing as the north-east monsoons of India, and which prevail during January and February over India, that is, during the same time as the easterly and north-easterly breezes of the Arctic Regions. Now January and February is the period of the greatest intensity and extension of the great anticyclone, an intimate study of which from the North Pole to the tropic cannot fail to be of the greatest possible value for an accurate knowledge of that part of the terrestrial globe which contains about three-quarters of the inhabitants of the world. The ice movements which troubled Peary, and made his earlier attempts futile, and added difficulty and grave risk to his last successful journey to the North Pole, are also ultimately caused by the winds flowing from the great winter anticyclone of northern Asia.
This one example is a striking illustration of the value of Arctic exploration from a meteorological standpoint. During any northern winter if this Eurasian anticylcone from some cause or other is not so intense or so extensive in area, it means that there is a breakdown of the north-east monsoons in India, and a breakdown of the north-easterly system in the Barents Sea. Hence, we have this further relationship, that if there is a breakdown of north-east monsoons in India, there is a minimum amount of pack ice in the Barents Sea and on the shores of Spitsbergen, which reminds one of Mossman's dictum, that the failure of the winter rains on the coast of Chile, south of lat. 33°, means that the Weddell Sea is comparatively clear of ice.
It must be emphasised that well-trained meteorologists are essential for conducting thoroughly satisfactory observations, for there are many errors that unguided amateurs are apt to commit, however conscientious they may be in the task set them.
The selection and setting up of instruments, either on board ship or ashore, is important. Before the departure of the Scotia I was aware that temperature observations on board ship were often vitiated by the warmth from the ship itself according to the relative direction of the wind. Yet, in spite of this well-known fact, I have not known any other ship but the Scotia fitted out with a double set of thermometers, one on the port side and the other to starboard. This was the arrangement which Mossman, at my suggestion, adopted. Another important consideration in the placing of thermometers on board ship is to see that they are placed in a thoroughly exposed position in good louvred screens, which can get a free breeze across them: not up against a bulkhead or under a bridge or any other such place. On the Scotia they were fitted up against stanchions on each side of the quarter on the poop deck, about five feet above the level of the deck, and projecting as much as 18 inches clear of the ship's side, where they were in an absolutely open position.
When the temperature observations were being made the dry and wet bulbs on both sides of the ship were read, and the readings of those on the weather side were recorded as the correct ones. It is interesting to note that errors of several degrees were observed on the leeside thermometers on many occasions, especially when the Scotia was in high latitudes and low temperatures prevailed. Furnaces, galley and cabin stoves, and the general higher temperature of the ship itself all affected the readings. On rare occasions when the wind was absolutely ahead, and it was thought that both the port and starboard thermometers might be affected, Mossman used sling thermometers on the foc'sle head, but these, as a rule, did not vary a tenth of a degree Fahrenheit from the lowest reading of the quarter thermometers. Furthermore, when the Scotia was wintering in Scotia Bay, and when there was a regular series of meteorological instruments set up in thorough observatory fashion ashore, it was found that the weather-side deck thermometers compared absolutely with those on shore.
"Except on rare occasions," says Mr. Mossman, "one side of the ship was definitely a weather and the other a lee side. It may be worthy of notice that there was usually a difference of one or two degrees between the weather and the lee side of the Scotia, the instrumental readings on the lee side being affected by heated currents from the cabins and engine-room,—hence the importance of having thermometer screens on both sides of the poop. On one occasion the lee side was as much as 5° warmer than the weather side, and on another occasion, during a calm, a difference of nearly 10° was noted."
A further check was afforded by the records of three Richard thermographs, which gave continuous records of temperature. Some little trouble was at first experienced by Mossman with the wet bulb thermometers, due to saline accretions on the muslin and bulb of the instrument, such as are formed on every exposed part of a vessel at sea. The result was that in the course of a week or so a coating of salt formed round the bulb which could with difficulty be removed by scraping with a knife, or took some time to dissolve even when the thermometer was soaked in tepid water. But by changing the water in the reservoir frequently, and placing a fresh piece of muslin on about once a week, thoroughly satisfactory results were obtained, the wet bulb being further syringed daily with distilled water. The Richard hair hygrograph was employed as a check, so that any serious discrepancy between the two instruments was at once apparent. For measurement of the intensity of solar radiation a black bulb thermometer in vacuo was employed. This was fixed in a stand secured to the bridge in such a position that the sun could shine on it as nearly as possible at all hours of the day.
Two barometers of the new marine pattern were in use: one being placed in the deck laboratory at a height of seven feet above the sea, while the other was a spare instrument and was kept aft in the cabin. Three self-recording Richard barographs yielded continuous traces of barometric pressure. One of the late Dr. Black's marine rain-gauges was placed aft on the poop well clear of the deck. Its position was changed occasionally as circumstances arose, in order that it might always be on the weather side. The exposure—taking into account the various difficulties attending rainfall observations at sea—was a very good one, as the gauge was never sheltered by the sails. The thickness of the rainband in the spectrum of sunlight was taken daily at noon, and the temperature of the sea surface was observed every four hours, and at more frequent intervals when rapid changes were in progress.
For ascertaining rapid fluctuations of the atmospheric pressure a Richard statoscope was employed; this is really an extremely delicate recording aneroid, in which changes of pressure are magnified twenty-five times. This instrument was also used for recording the height of waves. A chart put into motion by clockwork receives a trace of the pressure-fluctuations due to the rise and fall of the waves, the height of which could thus be calculated. Attempts were also made to fly kites for recording meteorological observations at high altitudes, but it was found difficult to get the kite clear away from the ship owing to eddies formed by the heavy masts, yards and rigging of a full-barque-rigged ship, although several of us were quite proficient in getting kites clear away from a small steamer which had less heavy rigging. Another drawback was that the speed of the Scotia was scarcely sufficient under some conditions to keep the kites flying well. It may be noted that Mr. John Anderson, the pioneer of meteorological kite-work in Scotland, had equipped the Scottish Expedition with a small machine for reeling in the piano wire attached to box-shaped kites of the Blue Hill pattern. Specially constructed meteorographs, made of aluminium, were carried up by the kites, on which a record of the vertical distribution of pressure, temperature, and humidity was graphically recorded.
While mentioning this high-altitude equipment on board the Scotia, it is appropriate to refer to the splendid services the Prince of Monaco has rendered meteorology in the North Polar Regions by the use of kites and balloons. The author had the advantage of accompanying the Prince on three of his voyages to the north-west of Spitsbergen, and of assisting him in making these observations.
"The launching of a kite," says the Prince of Monaco ("Meteorological Researches in the High Atmosphere," Scot. Geog. Mag., March 1907), "from a ship is always a delicate operation, and one which demands experience on account of the vortices found in the aërial wake of the ship, of which those visible in the aqueous wake are the image. Often when the apparatus has reached a height where it appears to be out of danger it may be caught by one of these risky vortices and precipitated into the sea. In stormy weather such a catastrophe may occur even after the kite has risen to a height of several hundred metres.
"When the wind is strong enough and the bridle (the object of which is to keep the face of the kite to which it is attached horizontal) is not very exactly balanced, the kite at once executes plunging zigzag movements which may produce such a strain as to break the line. When the kites have reached the greatest altitude permitted by the circumstances, the paying out of the wire is stopped, and, either by increasing the speed of the ship, or by heaving in the wire as quickly as possible, a little final augmentation of height is obtained. The recovery of kites, although somewhat delicate, presents less difficulty than their dispatch. As at the launching of the kite, a subsidiary line is used, which is run alongside of the bridle as soon as this is got hold of, so as to limit the motions of the kite.
"Unfortunately, even with the greatest care, accidents occur." Five or six or even more kites may sometimes be attached one after the other along the wire. Should the kite and instruments fall into the water, "it is interesting to note that the curves furnished by our instruments can resist a prolonged immersion without suffering damage when they meet with such an accident. The curve is a line traced by the pen on a layer of lamp black, deposited on the cylinder by the smoky flame of a petroleum lamp. In a case of immersion the carbonaceous particles disappear, but an excessively thin coating of grease, deposited with the carbon from the flame, remains and the line traced by the point of the pen is clearly visible in it with a magnifying glass.
"A notable instance occurred during one of my earliest experiments in the Mediterranean in 1904. An instrument was lost to the northward of Corsica, and was found on the shore of Provence fifteen days later. The curves traced in the greasy film on the recording drum were still perfectly visible, and were utilised with the others in Professor Hergesell's laboratory.
"A kite operation, at a height of 3,000 to 5,000 metres, lasts almost the whole day, and the ship, which must at times steam full speed (the yacht Princesse Alice attains a maximum speed of 13 knots) in order to enable the kites to pass through zones of light wind or of calm, may easily cover a distance of 50 or 60 miles during the operation."
But, besides kite observations at high altitude, the Prince of Monaco has made some very remarkable investigations in the Arctic Regions by means of small balloons, which he terms "ballons-sonde," which carry up instruments, and which, by several different ingenious devices, he recovers again. He has also made many valuable observations, by means of pilot balloons, which he has succeeded in following to the stupendous height of 97,700 feet, or 49½ miles from the surface of the earth, that is, three and a third times as high as the summit of Mount Everest—the highest mountain in the world.
After carrying on numerous investigations in the Mediterranean and in the North-east Trades, the Prince of Monaco in 1906 proceeded on his third voyage to the Arctic Regions, his destination being the Greenland Sea off the north-west of Spitsbergen. In Spitsbergen itself, he was to land a Scottish party under the author's leadership for the detailed survey of Prince Charles Foreland, and a Norwegian party under Captain Isachsen for the survey of part of the mainland; while he himself, associated with Professor Hergesell of Strasburg, was to explore the higher atmosphere. On July 13, 1906, I have interesting recollections of being one of a party of three, the other two being Professor Hergesell and Captain H. W. Carr, R.N.R., for so many years the Prince's commander and aide-de-camp, who conducted the theodolite work ashore at Deere Sound (recently erroneously called King's Bay), whilst the Prince of Monaco was on board the Princesse Alice, attending to the liberation of a pilot balloon—the first that was ever set free in the Arctic Regions. While Professor Hergesell followed continuously the ever-ascending balloon with the theodolite telescope, Captain Carr and I were reading the vertical and horizontal limb of the theodolite and recording our synchronous observations. Knowing its ascensional force Professor Hergesell was able to calculate the course and altitude of the balloon, which reached a height of 26,050 feet, where a W.N.W. wind was blowing at the rate of 28 metres per second. The weather was clear, calm, and sunny, and gave a very good opportunity to carry out this series of observations in a thoroughly satisfactory manner.
During this interesting investigation of the atmosphere the Prince of Monaco was much hampered in carrying out his programme by persistent fogs over the sea to the westward of Spitsbergen, although in the bays and on the land the weather was magnificent. Thus the dispatch of "ballons-sonde" which the preliminary experiments in the Mediterranean had rendered perfect of execution was stopped by this insurmountable difficulty. Twice only was it possible to dispatch them. Nevertheless, the information received was very valuable, since the registering instrument brought back curves from an altitude of 24,600 feet in latitude 78° 55′ N.
In this Arctic voyage the Prince had to resort to a new method on account of the constant presence of clouds which were down to a very low level although the horizon was clear, a condition that often prevails both in the Arctic and Antarctic Regions: this method allowed of a certain amount of exploration of the atmosphere though not so extensive as the method employed when the sky was cloudless, or when only detached clouds were present. The balloon was furnished with means capable only of taking it to such an altitude that it could regain the surface of the sea at a distance which does not exceed the limits of visibility. The ship is then stopped on the spot where the balloon was started, and attentive observers watch all directions in order to detect its return from above the clouds. One experiment of this kind that the Prince made succeeded perfectly, and the balloon, which had reached a height of 15,750 feet on a day when the sky was completely covered by very low clouds, was detected and recovered at a distance of twelve miles.
But the most remarkable results the Prince of Monaco has attained have been with pilot balloons. "These balloons," says the Prince, "which are small enough to be embraced by the arms of a man, have been followed with a special theodolite to the extraordinary altitude of 29,800 metres (97,700 ft.), if it is assumed that their velocity of ascent increased a little with the change of density of the atmosphere in the most elevated regions; or at the very least to an altitude of 25,000 metres (82,000 ft.). Further, the one which attained this height was, at the moment of its disappearance, at a distance of 80 kilometres (49½ miles) from the observers. So remarkable a result is explained by the transparency of the atmosphere in the Arctic Regions, a transparency which, under other circumstances, permitted us to follow distinctly on the snow of a glacier, at a distance of 40 kilometres, the movements of a party of four persons whom I had sent on a mission of exploration in the interior of Spitsbergen."
This translucency of the atmosphere is a well-known character of the Polar Regions. Captain Armitage says, when the Discovery was off Cape Washington, Victoria Land, "the atmosphere was exceedingly clear, as may be imagined from the fact that we could plainly see Coulman Island and Mount Erebus at the same time, although they are 240 miles distant from one another." In Spitsbergen, at sea-level, I have seen the mountains on the south side of Bell Sound from the north end of Prince Charles Foreland quite clearly—a distance of 100 miles; and I could quote many other instances of extraordinary visibility. The only comparison in temperate climates is from mountain tops: from the summit of Ben Nevis I have seen at one time the Black Isle and the waters of the Moray Firth, the Pentland Hills (or Arthur's Seat), Barra Head (100 miles distant), and the coast of Ireland (120 miles distant), though it is unlikely that one could ever see Ben Nevis from sea-level at Barra Head.
"The information furnished by the pilot balloons, which carry no instrument because they are sacrificed, concerns questions of capital importance for meteorology—the direction and the velocity of the upper currents. Now our pilot balloons of 1906 have taught us that there exist in the Arctic Regions in the neighbourhood of the 80th parallel, at a height of about 13,600 metres (44,600 ft.), certain winds of 60 metres per second (132 miles per hour), a force of which we have no equivalent at the surface of the globe. Their direction was S. 68° W."
The Prince of Monaco made thirty explorations of the high atmosphere in the Arctic Regions in the vicinity of Spitsbergen in 1906, and, in carrying out this work, added more to our knowledge, not only of the meteorology of the Arctic Regions, but also of our knowledge of the meteorology of the world than almost any recent investigator. This is more especially the case because before and since he has carried out further extensive exploration of the upper atmosphere in the North-east Trades and in the Mediterranean, which can be correlated with the valuable work he accomplished in the Polar Regions.