The Origin of Cyclones of Middle Latitudes

The Present Position of Meteorology as a Science.—The preceding pages give an outline of such parts of the Science of Meteorology as may be considered to be definitely accepted. In spite of the immense volume of literature on the subject, the amount of progress which has been made is still slight, and there remain many outstanding problems. Among these may be noted (1 ) various aspects of the distribution of temperature in the free atmosphere, (2) the nature of turbulence, (3) the physical causes underlying the formation of depressions and anticyclones, and (4) the true nature and method of maintenance of the gen eral circulation.

Under heading (I), at least four difficulties remain unsolved.— (a) The approximate constancy of the mean lapse-rate at all heights within the troposphere and in all latitudes. (b) The sudden nature of the change in lapse-rate at the tropopause. (c) The relative constancy of the lapse-rate within the stratosphere, and (d) The decrease of temperature within the stratosphere from equator to pole. With regard to (2) the defects of exist ing theories have been outlined on page 351. With regard to (3.) and (4), which are perhaps only different aspects of the same problem, there is not available any satisfactory theory of the origin of the depression and anticyclone, and even the sub tropical anticyclonic belts which form the most permanent fea ture of the earth's atmosphere have as yet not been adequately explained. Nor is it clear to what extent changes of pressure are to be ascribed to the effects of instability in the lower atmos phere, or to the effects of advection in the upper atmosphere.

Until these problems have been solved at least in part, it is dif ficult to see how the practical application of the science of meteorology to the successful forecasting of weather can make any further progress.

history of Meteorology. Napier Sha

w, Manual of Meteorology (vol. i., 4 vols. 1926 etc.). For data of observation, H. H. Hildebrandsson and L. Teisserenc de Bort, Les Bases de la Mete

orologie dynamique (1898-1907) ; J. von Hann, Handbook of Climatol ogy (trans. R. de Courcy Ward, 1903) and Lehrbuch der Meteorologie (3rd rev. ed., Leipzig, 1915) ; Napier Shaw, Manual of Meteorology (vol. ii.) ; A. F. Kendrew, The Climates of the Continents (2nd ed., 1927).

Methods of Computation: The Computer's Handbook (pub. by the Meteorological Office, 1921, etc.).

General Text-books. Cleveland Abbe,

Mechanics of the Earth's Atmosphere (1862, etc.) ; A. Angot, Traite de Mitiorologie (1899, znd ed. rev. 1907) ; N. Shaw, Forecasting Weather (1911, 2nd ed. 1923), and The Air and its Ways (1923) ; V. F. K. Bjerknes, Dynamic Meteorology and Hydrography (1910–II) ; W. Georgii, Wettervor hersage (Dresden and Leipzig, 1914) ; F. Exner, Dynamische Meteor ologie (1917 2nd edition 1925) ; W. J. Humphreys, Physics of the Air (1920 2nd edition 1929) ; A. E. McL. Geddes, Meteorology (1921) ; R. T. Glazebrook, Dictionary of Applied Physics (vol. iii.; 5 vols., 1922-23) ; R. Suring, Leitfaden der Meteorologie (Leipzig, 1927).

Introductory Textbooks. W. H. Pick,

A Short Course in Elementary Meteorology (1921, 2nd ed. 1926) ; R. G. K. Lempfert, Meteorology (1920) D. Brunt, Meteorology (1928).

Periodicals.

See also the Quarterly Journal and the Memoirs of the Royal Meteorological Society (London), the Meteorologische Zeit schrift (Berlin), the Beitrdge zur Physik der freien Atmosphere and Veroffentlkhungen des Geophysikalischen Instituts (Leipzig) ; the Geofysiske Publikationer (Oslo) ; The Monthly Weather Review (Washington) ; the Geophysical Memoirs and the Meteorological Magazine published by the Meteorological Office, London ; also The Marine Observer (1924). A bibliography of recent papers is published biennially by the Royal Meteorological Society. Bibliographies also appear in most issues of the Monthly Weather Review and the Meteor ologische Zeitschrift. (D. BRu.) METER, GAS: see GAS METER.