Arctic climate

“ Temperate Climates in the Arctic Regions.—As we have just seen, the geological evidence of the persistence of sub-tropical or warm climates in the north temperate zone during the greater part of the Tertiary period is almost irresistible, and we have now to consider the still more extraordinary series of observations which demonstrate that this amelioration of climate extended into the Arctic zone, and into countries now almost wholly buried in snow and ice. ”

“ The geological evidence is complete as to the existence of a genial climate in Tertiary times as far north as the present land extends, and of a climate less severe than that of to-day in the Quaternary period. The existence of raised sea margins in many Arctic lands and especially in the American Arctic archipelago bears evidence to a recent elevation of the land, or a withdrawal of the sea, which has been influential in forming some of the most prominent features of the present configuration. It is noteworthy that no great mountain range runs into the Arctic region. ”

“ It is difficult to determine with precision the limits of the Arctic lands, since many countries situated as low as latitude 60° or even 50°, such as South Greenland, Labrador, Alaska, Kamchatka, or the country about Lake Baikal, have in their climate and productions a decidedly Arctic character, while others of a far more northern position, such as the coast of Norway, enjoy even in winter a remarkably mild temperature. ”

“ When the high excentricity passed away the glacial epoch also passed away in the Temperate zone; but it persists in the Arctic zone, where during the Miocene there were mild climates, and this is due to the persistence of the changed geographical conditions. The present Arctic climate is itself a comparatively new and abnormal state of things due to geographical modification. ”

“ Southern icebergs are true glaciers afloat. Arctic winds are dry enough to evaporate much of the ice and snow that fall and form in the north polar basin. As compared with arctic climates, antarctic are marine, arctic continental; and for the very reason that the English climate is cooler in summer and warmer in winter than the Canadian, so is winter at the south pole much less severe than winter at the north. The relative difference between the two polar climates is, as the barometer indicates, even greater than is the difference between a Canadian and an English winter. ”

“ A great amelioration of climate would also be caused by the breaking up or the lowering of such {191}Arctic highlands as now favour the accumulation of ice; while the interpenetration of the sea into any part of the great continents in the tropical or temperate zones would again tend to raise the winter temperature, and render any long continuance of snow in their vicinity almost impossible. ”

“ In contrast to the monotonous extremes of climate in the hot and cold zones, temperate lands are characterized by the intermediate degrees of annual temperature and marked seasonal diversity which are so favorable to human development. In Arctic lands labor is paralyzed by cold as it is by heat in the enervating and overproductive Tropics. In one, the growing season is too short and ill-favored; in the other, too long to stimulate man to sustained industry. ”

“ But as animal and vegetable life are largely affected by climate, it may be justly said that wherever an Arctic climate prevails there we shall find an Arctic or Polar region; and, hence, many countries below even the 60th parallel, such as Kamtschatka, Labrador, and South Greenland, fall within the Circumpolar boundary.
The waters surrounding the North Pole bear the general designation of the Arctic Ocean. But here again it is almost impossible to particularize any uniform limit southward. It joins the Pacific at Behring Strait in about lat. ”

“ The total absence of the sun from the Arctic regions during a large part of each year makes the climate severe and the country desolate. Direct sun rays are necessary to insure warmth, and the regions within the Arctic circle receive at the best only slanting rays. ”

“ After this ice-development had reached its maximum limits and remained there for perhaps a thousand years, retreat set in, and the Scandinavian ice once more withdrew from Germany and Denmark to the Baltic basin. But its edge was never far from the German coast, and occasionally readvanced across it, for numerous fossiliferous deposits are intercalated in boulder-clay. The fauna and flora, which are well known, point to an arctic climate. ”

“ In both cases, the ice presses from a region, colder and less favoured by climate, towards one warmer and more favoured. In the Alpine glaciers, the movement is from above downwards; in the Frozen Ocean, the movement is from a higher to a lower geographical latitude. In both cases, the tongues and spurs of the masses of ice formed by the configuration of the land or by currents of the sea, terminate, whenever they reach an isothermal curve of altitude or latitude, the mean temperature of which suffices to dissolve them or prevent their formation. ”

“ What does materially affect climate, however, is the variation in the annual range, Equator-wards, of the great Arctic currents, which convey on their surface not only the bergs, but the vast compact fields of pack-ice, extending over areas of many thousands of square miles, and thus bringing about a reduction of temperature, infinitely in excess of that produced by the bergs. ”

“ There was, indeed, a certain logical consequence in the belief of an inner Polar Sea, as long as it was unknown that ice is formed on the open sea as well as on the coasts. There was also one argument, which made the existence of such a sea not altogether improbable. It might be assumed, that the formation of ice renewed every year in the Arctic regions, would necessarily produce eternal bulwarks of congelation and destroy all organic life, unless sea-currents modified these extremes of climate. ”

“ But if there were other and wider openings into the Arctic Ocean, a vast quantity of the heated water which is now turned backward would enter it, and would produce an amelioration of the climate of which we can hardly form a conception. ”

“ If the ice islands in the Atlantic, like lumps of ice in a pitcher of water, chill our climate in spring, they are at the same time agents in preventing a still more serious secular chilling which might result from the growth without limit of the Arctic snow and ice. They are also constantly employed in wearing down the Arctic land, and aided by the great northern current from Davis's Straits, in scattering stones, boulders and sand over the banks along the American coast. ”

“ The picture we have drawn of the high northern latitudes in early Tertiary times is vastly different. A great warm ocean occupied the Arctic regions, fed by three ocean currents analogous to the Gulf Drift, and the fall of temperature was gradual from the tropic to the pole. The return colder currents were mainly along the ocean floor and with little ice-formation the storms were few and not severe. On the western shores of the continents mild rain-bearing south-west winds prevailed, and a quiet moist warm atmosphere existed which was especially favourable to plant life. ”

“ Thus the heat of the continuously shining summer sun at this particular part of the Arctic region is continuously absorbed by this powerful action, and a severity quite exceptional is thereby produced. Every observant tourist who has crossed an Alpine glacier on a hot summer day has felt the sudden change of climate that he encounters on stepping from terra firma on to the ice, and in which he remains immersed as long as he is on the glacier. ”

“ The occurrence of a recent glacial epoch of great severity in the northern hemisphere is now universally admitted, but the causes which brought it on are matter of dispute. But unless we can arrive at these causes, as well as at those which produced the equally well demonstrated mild climate in the Arctic regions, we shall be quite unable to determine the nature and amount of the changes of climate which have occurred throughout past ages, and shall thus be left without a most important clue to the explanation of many of the anomalies in the distribution of animals and plants. ”

“ What may have been the cause of these amazing changes of climate? The readiest answer seems to be—a different distribution of sea and land; but there is no reason to believe that in the miocene times there was less land in the Arctic zone than at present, nor can any possible combination of water and dry land be imagined sufficient to account for the growth of laurels in Greenland or of plantains in Spitzbergen. Dr. Oswald Heer is inclined to seek for an explanation of the phenomenon, not in mere local terrestrial changes, but in a difference of the earth’s position in the heavens. ”

“ This continuance of sunshine, in spite of the moderate altitude of the solar orb, may produce a very genial summer climate at the Pole. I say “may,” because mere latitude is only one of the elements of climate, especially in high latitudes. Very much depends upon surface configuration and the distribution of land and water. The region in which our Arctic expedition ships have been ice-bound combines all the most unfavorable conditions of Arctic summer climate. It is extremely improbable that those conditions are maintained all the way to the Pole. ”

“ This is in marked contrast to the Greenland coast opposite, where all the outer cliffs and the shores are comparatively free from snow and ice. The cause of this marked difference of climate is probably due to a divergence of direction of currents along these coasts. On the Greenland side a southerly current, comparatively free of ice, allows the open sea to raise the general temperature, while on the Ellesmere side the Arctic current, with its continuous stream of ice, blocks the bays and does not allow the open water to ameliorate the cold of the ice-covered lands. ”

“ As the continent grew by the slow upheaval of the land, and the islands gained in height, and the climate around these hills grew milder, the Arctic plants would retreat to higher zones, and finally occupy an elevated area, which probably had been, at first, or in the Glacial period, always covered with perpetual snow. ”

“ Those who have worked at the microscopic life of the Arctic Region know that it must survive extreme cold. somehow. The Arctic Region has a, genial summer climate of some months duration, with abundant water and a vegetation of higher plants. The winter might be passed by resting eggs, and a new generation produced each summer. ”

“ The physical changes upon the earth's surface during the past 80,000 years modified the changes of climate even in the Arctic regions, so that the intense cold of the former epochs was much modified during the latter epochs. ”

“ At the present time the warm water thrown into the North Atlantic, co-operating with the prevalent westerly winds, not only increases the temperature of its whole waters, but gives an exceptionally mild climate to western Europe. Still the countervailing influence of the Arctic currents and the Greenland ice, is sufficient to permit numerous icebergs to remain unmelted on the coast of Labrador and Newfoundland throughout the summer. ”

“ The climatic conditions which obtain about the borders of small, local glaciers, are not a safe guide as to climatic conditions which obtained about the margin of a continental ice-sheet, any more than the climatic conditions which obtain about a small inland lake are a safe criterion as to the climatic conditions about a sea-coast. The general principles of climatology, as well as specific facts concerning plant distribution, seem to us to indicate that the climate about the border of a continental ice-sheet must have been arctic. ”

“ Northward of the temperate zone the rainfall generally decreases as we approach the arctic regions; except where the influence of warm ocean currents to windward creates comparatively local exceptions, as in the case of Norway and Alaska. ”

“ But, in order that the tropical currents should be able to flow into the high latitudes, in quantities sufficient to cause all lands and seas situated in such latitudes to enjoy a mild climate, it would be necessary that the land should extend unbroken, or nearly so, from the arctic to the antarctic circles. ”

“ For it must be remembered that the Arctic summers are, even now, really hotter than ours, and if the winter's cold were abolished and all ice-accumulation prevented, the high northern lands would be able to support a far more luxuriant summer vegetation than is possible in our unequal and cloudy climate. ”

“ When, however, geographical conditions favour warm Arctic climates—as it has been shown they have done throughout the larger portion of geological time—then changes of excentricity, to however great an extent, have no tendency to bring about a state of glaciation, because warm oceanic currents have a preponderating influence, and without very large areas of high northern land to act as condensers, no perpetual snow is possible, and hence the initial process of glaciation does not occur. ”

“ The result is that all the great equatorial currents of the ocean are impelled into the northern hemisphere, which thus, in consequence of the immense accumulation of warm water, has its temperature raised, so that ice and snow must, to a great extent, disappear from the Arctic regions. In the prevalence of the converse conditions the Arctic zone becomes clad in ice, and the southern has its temperature raised. ”