no METEOROLOGY 



METEOROLOGY 1 



The events that have marked the progress of meteorology during the past few years 

 may be briefly summed up under the following heads, (i) The great development of 

 radiotelegraphy, by means of which our daily weather maps now cover the oceans and 

 distant continents, so that every morning we have spread before us the general condi- 

 tion of the atmosphere over the whole northern hemisphere. (2) The remarkable de- 

 velopment of the study of the atmosphere at altitudes of 10 to 30 kilometers by means of 

 kites, pilot balloons and sounding balloons, leading to the establishment of the existence 

 of an isothermal or relatively warm layer at altitudes above 9 to 12 kilometres, due to 

 the atmospheric absorption of terrestial radiations. (3) The publication (1907) of E. 

 Gold's admirable survey of our knowledge of the upper atmosphere, the analogous 

 summary by A. Wegener (1912), and the simultaneous publication (1909) by Gold and 

 Humphreys of the importance of terrestrial radiation and atmospheric absorption in the 

 formation of the isothermal layer. The radiation from the earth, ocean and air is 

 mainly the same as that from water and aqueous vapour. Nearly all the rays that enter 

 the gaseous and aqueous envelope of the globe in their passage outward are caught in 

 the vapour atmosphere and radiated anew as from a water surface. The total resultant 

 radiation is as though it issued from a total radiator or black surface at an elevation of 

 3 or 4 kilometres, which is about the centre of gravity of all the aqueous vapour floating 

 in the atmosphere. Convective equilibrium and adiabatic control of temperature 

 prevail up to 9 or n kilometres or throughout the so-called convective region. Above 

 this is Dr. Gold's advective region, or Leon Teisserenc de Bort's isothermal region, or 

 his stratosphere. Humphreys (Mt. Weather Bulletin, Vol. 4, p. 408) concludes that the 

 air above n kilometres must have a uniform temperature of minus 55 degrees centigrade 

 and is free from vertical convection, also that the volume percentages of gases at this 

 altitude are the same as at the surface of the earth, but above this level the lighter gases 

 gain in volume with elevation more than the heavy gases. (4) The determination by 

 Humphreys of the zonal intensities of the earth's planetary radiation of heat, per unit 

 of time and area at different latitudes, showing a maximum between latitudes 30 and 

 65 north but a minimum at the equator; this depends essentially on the atmospheric 

 vapour and its radiating power. (5) The development, due to Bjerknes, of graphic 

 methods of studying the dynamics of the atmosphere. The approximate solutions 

 hitherto obtained by many scholars undoubtedly need revision in the light of the new 

 methods devised at Christiania and now being published by the Carnegie Institution at 

 Washington in Bjerknes's Dynamic Meteorology. (6) The increasing interest in 

 precise climatology and its evident importance to the physiography of the' globe and to 

 all human labours. The publication by Hann of the enlarged third edition of his 

 Climatology enables all interested therein to study this subject satisfactorily. (7) The 

 publication of Hann's new edition of his elaborate " Lehrbuch der Meteorologie " and 

 several general treatises by others, adapted to popular or educational purposes, such 

 as the works of A. Wegener, Sir John William Moore, Willis L. Moore, W. H. Milham, 

 A. Klossovski, and especially Forecasting the Weather by W. N. Shaw, which is really an 

 up-to-date meteorological memoir and summarises nearly all that is at present known of 

 the dynamical problems bearing upon the practical art of weather forecasting. (8) The 

 establishment of weather bureaus by the Commonwealth of Australia and by the South 

 African Union. (9) The determination of the altitude of the aurora borealis by Stoer- 

 mer, by photographic methods that give us for the first time some accurate knowledge 

 on this subject; with this may be associated A. Wcgener's co-existence 

 of hydrogen and geocoronium at all altitudes above 50 kilometres. (10) The publi- 

 cation of Prof. Pernter's Meteorological Optics (completed after his death by Dr. Felix 

 M. Exner), the most comprehensive work on the subject now available. 



International Ballooning. In 1907 Professors Hellmann and Hildebrandsson compiled 

 the "Official International Meteorological Codex" on behalf of the "International Meteor- 

 1 See E. B. xviii, 264 el seq., and allied articles. 



