Imágenes de páginas
[ocr errors]

below the freezing point in the daytime, and the nights when this has been the case have been exceedingly rare. Generally the month of February is the coldest in Denmark; this year it has had the character of early spring. The mild winter has been blessed by everybody, except the furriers and the coal-merchants. Particularly the latter are complaining bitterly. They are losing a great deal of money they say.

Cities like Helsingfors, Revel and Riga, which are usually buried in snow at this time of the year, have up to the present experienced nothing more wintry than a few nights of frost.

Latest reports, however, show that spring weather has come to an abrupt end.

LONDON, March 3, 1925.—While the European Governments are concerning themselves over the date for the introduction of "Summer time,” there has not yet been the slightest prospect of summer temperature. On the contrary, winter is lingering over Europe unusually late and a heavy snowfall has reached as far south as Naples, with the curious phenomenon of a snow-capped Vesuvius emitting fire.

Violent snowstorms have been experienced in the Rhineland and holiday seekers on the Riviera are finding extreme discomfort in the cold easterly winds, while severe frosts have been registered in South Germany.

England, after a comparatively mild winter, remarkable more for the heavy rainfall than the cold, has had during the past week the severest cold of the whole winter, with snowstorms in the north and a general biting easterly wind. This is held responsible for the epidemic of influenza.-N. Y. Times.

BRUSSELS, March 13, 1925.-Three days of severe cold weather, with a snowfall of more than a foot, has seriously interrupted transport and telegraphic communication services in Southern Belgium. Wild boars, driven from the Ardennes heights, are roaming the countryside.

NAPLES, March 19, 1925.-Three poor persons forced to spend the night in the open were found frozen to death today as the result of an unprecedented cold spell. Intense cold weather is also reported in Calabria.


The reign of “intense cold and storms” came to an end in eastern United States early in February.

The past February had temperatures equal to the average for late March in much of the eastern United States. It was the warmest on record with but one exception, February, 1890, when the temperature averaged slightly higher.

Maine Wants a Whole Winter

Portland people may be pleased with the brand of weather southern Maine has been getting in February and with the melting of the snow but back in the country it is an entirely different story, and the disappearance of the snow is causing consternation.

Up state they feel that snow is as necessary to the prosperity of Maine as nourishing food is to the growing child. The lumberman needs it. So does the farmer who would get his annual supply of cordwood. Snow is a protector of the ground and plant life and it is a fertilizer. All this may be overlooked by the city dweller who thinks of snow only as an impediment to travel and something which brings work in sidewalk shoveling and makes traveling soft and disagreeable.

Lightning Bolt Burns Barn During Hard Snow Squall BOWDOINHAM, Me., Feb. 28, 1925.-A bolt of lightning, in the midst of a high windstorm bearing alternate rain and snow, yesterday after

noon struck and burned a large hay barn here owned by E. P. & W. B. Kendall, grain dealers.


Unusually heavy rains caused great damage in Southern Peru during the last ten days of January. Such serious washouts occurred along the Southern Railway lines between Arequipa and Mollendo that before service could be restored bridges had to be constructed over gulleys washed out by the floods. The Harvard Observatory at Carmen Alto reported that the rainfall in the Arequipa region was the greatest since February, 1893. The average yearly rainfall there is about 100 litres per square metre; [100 mm., abt. 4 in.] during the last ten days of January 131.5 litres per square metre fell; on the one day, January 27, a rainfall of 32.5 litres per square metre was recorded.-A Peruvian Newspaper.

Saw a Desert Turn Into Fertile Plain

A warm current called El Nina, or The Child, because it usually comes before Christmas, swept southward along the west coast of South America in greater volume than ever known before, bringing with it torrential rains to sections that have not known rain since the days of Pizarro, according to Dr. Robert Cushman Murphy, Assistant Director of the American Museum of National History.

Dr. Murphy, who just returned from South America, told yesterday of studies of ocean currents off the coasts of Ecuador and Peru.

El Nina turned thousand of miles of desert into paradise almost over night, according to Dr. Murphy, as it caused millions of hardy seeds which had lain dormant in the ground through decades of drought to sprout and grow with incredible vigor. In a week brown and red landscapes had been painted green, and Dr. Murphy and his companion, Van Campen Heilner, caught hundreds of fish in the streets of Talaro, a desert oil town, where rain had not fallen previously for thirty-four years. This town was in a parched plain as lifeless as the Sahara when the scientists first saw it before January 12, when El Nina swept down the coast, but on March 7, when they reached the town, the horizon was one of lush grasses, flowers and foliage, and the place was a Venice with myriads of minnows swarming down its canals.

The rains, torrential and continuous, which fell for weeks after the arrival of El Nina off the coast, had interlaced the whole desert with streams.

"There is ordinarily no rain at all along the South American coast from Chili," said Dr. Murphy. "This is because of the cold Humboldt current which flows north. The wind carried water from the Humboldt current to the land, but the land is warmer than the ocean and the air expands and gives up none of its water as rain. But this warm current this year flowed further south and apparently in much greater volume, and charged the winds with moisture which was condensed in continuous rainfalls, visiting some regions where rain has never been reported, and, as far as we know, had not fallen since before the visit of Pizarro in 1551.

[ocr errors]

For hundreds of miles in this region there was not a roof that was ever needed as a protection against rain. They were all sieves. Other houses had practically no foundations and became temporary houseboats.

"The greatest economic loss is that of the guano on the islands off Peru. Last year more than 119,000 tons, or $9,000,000 worth was mined from the guano islands of Peru."

When El Nina arrived on January 12 off the coast of Ecuador the scientists were able to go out in launches to time the current, take the temperature, measure the density of the ocean water and make other observations. The temperature of the ocean rose from 63 to 75 degrees in a day.”—N. Y. Times, April 1, 1925.

Continuous rainfall for over a month (at Mt. Montezuma, in the most cloudless region of Chile) made solar observations impossible. The River Loa became a raging torrent, and the excessive rainfall caused great damage to bridges and property. Sci. Serv.



Instead of using instruments to measure the climatic elements or to appraise the daily weather as a whole, we may observe the periodic phenomena of plant and animal life and the distributions and associations of the several species to indicate the facts of climate. In the spring especially we have before us every day new indications of the advancing season, not in the higher temperatures and longer days alone, but in the swelling of buds, the blossoming of early flowers, the arrival of birds and the appearance of bees and flies. According to his bioclimatic law1 Dr. Hopkins finds that the upward and northward advance of spring averages four days for one degree of latitude, 400 feet of altitude or 1 degree F. rise in mean temperature, and that the advance of autumn is at the same rate in the opposite direction. Dr. Hopkins has found also that there is an average difference of 32 days in 40° of longitude, spring on the Pacific coast arriving phenologically earlier than spring at the same latitudes on the Atlantic coastal plain. On the immediate Atlantic shore the cold water induces a local delay in the arrival of spring. Other major sources of departure from the average are slope, wet vs. dry soils, type of vegetation, early or late individuals, and locally early or late seasons.

Bird migration2 in the spring is dependent upon food supply. Wild ducks move northward when ice on rivers and lakes has disappeared sufficiently to allow them access to their food. Other birds are similarly limited as to their northward rate by the dates at which their particular food supply becomes available. Different species requiring different sorts of food, therefore, migrate at different periods and at different rates. A study of bird migration and the weather recently made by Prof. Frank H. Smith of the University of Illinois shows that, over a period of years (1909-1916) birds came in waves, by far the greatest number arriving on days when an approaching low caused a rise in temperature and southerly winds.3 In the fall, failing food supply starts some flocks southward. A number of the English starlings of the northern states, after more than 30 years' residence, migrated southward for the first time in the fall of 1923.4 "Until recently through sheer ignorance, they have had to adapt themselves to a climate wholly unnatural in its severity, for at home in northern Europe, the species migrates regularly to southern Europe." Their first knowledge of migration in America, ornithologists believe, probably came from their

1 Hopkins, A. D.: Periodical Events and Natural Law as Guides to Agricultural Research and Practice, Mo. Wea. Rev.. Supplement. No. 9. 1918.

For a full discussion of this subject, see Bulletin No. 185 of the U. S. Biological Survey by W. W. Cooke.

Smith. Frank: The correlation between the migratory flights of birds and certain accompanying meteorological conditions, pp. 32-35, State of Illinois, Circular No. 151, 1921. pp. 21-29. See note in Bull. Amer. Met'l Soc.. April. 1924, pp. 56-57.

* Sci. Service News Bulletin, No. 140 C & D, Nov. 28, 1928.

contact with the flocks of blackbirds and grackles with which they mingled.

The dates for planting of garden truck in any locality are often estimated from a knowledge of the average date of the last killing frost. Since seasons frequently differ from the average, however, the progress of natural vegetation is usually a safer guide for farm operations. "Some examples of commonly recognized events in the advance of the season are the following: the opinion of the Indians is that the proper corn planting time is when the white oak or maple leaves are the size of squirrel ears; the saying in the Rocky Mountain region that sheep shearing should not be done until the 'spring sown grain begins to carpet the fields in green,' or 'the wool goes off as the fruit blossoms come on;' calling Amelanchier Canadensis or lance-wood' bush the 'shad bush' because when it came into bloom it was recognized along the Atlantic coast that it was time to fish for shad. The ornamental shrubs are more or less constant in this response to the advance of the season and serve as very good guides." 5

In spite of the wide application of such data, however, there have been comparatively few phenological observations published in the United States. In Canada, in contrast, phenological observations are carried on in every province, and are published annually. For over thirty years local nature observations have formed a part of the curriculum of every school in Nova Scotia, where record sheets are sent to every teacher on which are set down the dates of the first leafing, flowering and fruiting of plants and trees, both wild and cultivated; the beginning of farm operations; the first appearance in the locality of birds migrating north in spring and south in autumn; the opening and closing of rivers and lakes, the highest and lowest water in streams; the first and last snow and frost; and the number of thunderstorms. Observations are made by pupils on their way to and from school, and as some of them radiate as far as two miles from the schoolroom, few changes in the district can take place without coming to their notice. These records have been compiled from year to year so that with very little trouble to any one person a wealth of phenological observations has been compiled."

Dr. A. D. Hopkins says in a recent letter, "Phenology as a science, or a branch of the new sciences of Bioclimatics, not only requires some knowledge of all the natural sciences, but long study and experience to gain sufficient knowledge of technical detail to warrant the undertaking of special lines of research; [and yet] as a matter of personal interest to lovers of nature in general, and as a source of instruction and inspiration to school children and young college students there is perhaps no subject that will serve the purpose better than simple records of observations on season phenomena of their immediate locality.” 8

Smith, J. W.: Agricultural Meteorology, N. Y., 1920, pp. 30-31.

In Trans. Roy. Soc. of Canada. See also No. 1667 in Bibliographie Géographique for 1928.

'Material for this paragraph was kindly sent by Col. A. H. MacKay, Supt. of Education. Nova Scotia.

Three recent publications dealing with phenological observations are found in the following magazines: (1) Nature. Oct. 25, 1924, p. 607: (2) Quart. Journ. Royal Met. Soc., Vol. 50, Oct., 1924. pp. 277-325: (8) Dr. E. Ihne's Phaenologische Mitteilungen, Arbeiten der Landwirtschaftskammer für Hessen, Heft Nr. 38.

[merged small][ocr errors]


Published Monthly by the American Meteorological Society at Worcester, Mass. Address All Communications and Exchanges to "Secretary, Am. Meteorological Society, Clark University, Worcester, Mass."

Vol. 6

APRIL, 1925

No. 4


The origin, nature, structure, and maintenance of ordinary cyclones and anticyclones constitute one of the major unsolved problems of meteorology. This problem is not only of the highest theoretical interest and importance, but is also extremely vital to the practical, or forecasting, phase of meteorology. The difficulties in the way of a complete solution comprise both those of an observational character and those of a theoretical nature.

The more prominent contemporary theories of the extratropical travelling cycloes of the lower atmosphere may, broadly speaking, be classified under three types: (1) The "wave theory," elaborated particularly by the Norwegian school; (2) the "drop theory," more especially associated with the Austrian school; and (3) the "vortex theory," favored by certain British and Japanese investigators. All these theories, however, possess more or less in common; and each is the result of a fairly long series of researches by several successive investigators.

The Polar Front Theory

Deprived of weather telegrams from the greater part of Europe during the World War, the Norwegian meteorologists found their isobaric charts, which covered only a very limited area, of comparatively little use for forecasting, and they were led to a serious attempt to use in practise a method of forecasting which V. Bjerknes had originally evolved from theoretical considerations. Detailed reports from a very close network of stations made possible an analysis of the phenomena of the cyclone, particularly the relation of temperature and rainfall to the pressure distribution, that brought to light many details not known before.

Of especial significance was the discovery of the existence in the normal cyclone of two lines of discontinuity, meeting at the center and dividing the cyclonic area into quite unequal portions: These two lines mark the boundary of a projection of warm air, generally from the southward, into a region of cold air. The line running from the center towards the eastern or advancing side is called the steering line, or warm front; under normal conditions it is marked by a rise of temperature, preceded by a considerable and prolonged fall of rain. The other line, running from the center in a southwesterly direction, is called the squall line, or cold front; it is marked by a sudden fall of temperature accompanied by a brief shower of rain. The cyclone is thus divided into

« AnteriorContinuar »