Discussion 



In reply to questions regarding the inconsistencies obtained by the 

 two distinct methods of approach Mr. Hutchings said that at present 

 he could offer no explanation for the inconsistent results obtained at 

 Earnscleugh, but it was suggested that the usual Fourier analysis of 

 the process of heat conduction should be modified to include represen- 

 tation by two independent parameters instead of one. 



Mr. Priestley pointed out that Mr. Swinbank, of C.S.I.R., Australia, 

 had made some very detailed experiments on soil conductivity and found 

 that conditions were far more complicated than had hitherto been 

 supposed. 



In offering a possible explanation of the discrepancy in K values 

 found by Mr. Hutchings, Mr. Priestley described an experiment by 

 Mr. W. C. Swinbank to determine directly the thermal conductivity of 

 soil. A note on this experiment has just been published {Q.J. Roy. Met. 

 Soc, 74, 321-322, July-Oct., 1948, p. 409). It appears that the tem- 

 perature behaviour of soil which is not waterlogged cannot be described 

 in terms of thermal conductivity alone, but a satisfactory explanation 

 must take into account the movement of water vapour and the heat 

 quantities involved in evaporation and condensation in soil interstices. 

 These quantities, though small, may 3^et involve sufficient latent heat 

 to mask the transfer of sensible heat. 



A MERIDIONAL AEROLOGICAL CROSS-SECTION IN THE 

 SOUTH-WEST PACIFIC! 



By F. LoEWE and U. Radok, Department of Meteorology, University 



of Melbourne 



Aerological information was until recently very restricted in the 

 Southern Hemisphere, particularly with respect to the higher part of 

 the troposphere and to the stratosphere. This has completely changed 

 during the war ; but very little of the accumulated data has yet been 

 published, and only part of a tentative cross-section through the South 

 Atlantic has become known. 



In this study 4,800 radiosonde flights from six coastal and three 

 inland stations of eastern Australia have been used to draw for the 

 summer and winter seasons vertical cross-sections of the average tem- 

 perature roughly along the eastern coast of Australia. The sections 

 have been extended northward through New Guinea to the Marianas 

 in 15° N. All these data have been carefully scrutinized. South of 

 Australia 100 flights from Macquarie Island, in 54° S, have been used, 

 and for the antarctic latitudes the great number of observations (about 

 100 flights) collected in the course of the United States Task Force 

 Operation " Highjump " in the summer 1946-47 have been utilized. 

 The southernmost data (140 flights) are those from the station " Little 

 America " on the Ross shelf ice in 78|° S., for which some still unpublished 

 data have been kindly supplied by Mr. A. Court. The temperature 

 cross-sections contain isotherms at a distance of 5° c. ; they extend 

 to a height of 16 km., or 10 miles. 



In summer (Fig. 2) below 10 km. the highest temperatures are found 

 in 15-20° S. Up to about 4 km. the continental Australian stations 

 give markedly higher temperatures than the coast in the same latitude ; 

 at higher levels the difference disappears. The continental influence is 



' A more complete \-ersion will be published in Journal of Meteorology. 



5G 



