of the convergence shows a nearly isothermal surface layer with temp- 

 eratures below zero degrees Centigrade. The increase in temperature in 

 the transition la3-er at greater depths does not appear here because of 

 the shallowness of the section. Section C-2, taken fifty-four days later, 

 indicates that surface heating has produced an area with a well-marked 

 subsurface minimum. The data in this section extend deep enough to 

 penetrate the region of positive gradient. Section C-3 shows this sub- 

 surface minimum and its northern boundary, serving as an indication 

 of the location of the boundary zone. 



The southward displacement of the converg.ence in the fifty-four-day 

 period between sections C-1 and C-2 may be related to an increase in 

 the thermohaline circulation in the subantartic region, coupled with a 

 decrease in the intensity of the transverse circulation related to the 

 prevailing westerlies in the Antartic region. This displacement appears 

 to be a seasonal phenomenon, with the convergence occurring farther 

 south in summer than in the colder months. In winter the cold 

 antarctic water extends farther north along the surface before sinking 

 to form the antarctic intermediate water at the convergence. The 

 northward displacement of the convergence between sections C-2 and 

 C-3 maj' indicate that the southward seasonal trend has been reversed 

 by late February, when section C-3 was obtained. 



ON THE CORRELATED FLUCTUATION OF THE KUROSIO 

 CURRENT AND THE COLD WATER MASS 



By MiTiTAKA Uda, Nagasaki Marine Observatory, 1949. Oceano- 

 graphical Mag., Vol. 1, No. 1. [Re'ad by title only.] 



ON THE VERTICAL EXTINCTION COEFFICIENT OF SEA- 

 WATER IN THE PACIFIC COAST OF JAPAN 



By Yositada Takenouti, Hakodate Marine Observatory 



1. Introduction 



The vertical extinction coefficient of sea-water has been measured bv 

 many authors at various localities of the world since Professors H. H. 

 Poole and W. R. G. Atkins had made their famous observations in the 

 English Channel by means of a photovoltaic cell. As for the Pacific 

 Ocean, Professor C. L. Utterback and his collaborators have made 

 many measurements in the north-eastern part of the ocean. In the 

 western part of the Pacific Ocean, however, a submarine illumination 

 had been scarcely measured. The author has made a series of 

 observations for under-water illuminations in waters near Japan and the 

 Japanese lakes, and he gave a standard value of vertical extinction 

 coefficient of sea-water as a function of wave-length for every class of 

 the colour of sea. 



2. Instrument and Method of Measurement 



A photovoltaic cell made by the Tokyo Electric Co., named " Mazda 

 photo-cell," has been employed for the measurement of under-water 

 illuminations. The aperture of the cell is 40 mm. in diameter. The 

 normal spectral sensitivity of Mazda photocell is illustrated in Fig. 1, 

 which is reproduced from the monograph written by Dr. H. Suzuki, 

 an expert of the Tokyo Electric Co. The spectral sensitivity of the 



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