ON THE SECONDARY UNDULATIONS OF TIDES CAUSED 

 BY THE CYCLONIC STORM ON APRIL 1-5, 1936 



By M. Nakano, Central Meteorological Observatory, Japan 



[Abstract] 



On the occasion of the cyclonic storm which swept along our Pacific 

 coast from 1st to 5th of April, 1936, conspicuous secondary undulations 

 appeared on the mareograms of tidal stations in various parts of this 

 country. In the present paper is reported the result of investigation 

 of periods, amplitudes as well as the time of occurrence of these 

 conspicuous undulations, and some discussions are made on their relations 

 with meteorological conditions. Figure 1 shows the positions of the 

 tidal stations and the track of the centre of the cyclone, where the 

 points marked with A , X , 0, and O show the positions of the cyclonic 

 centre at Oh., 6 h., 12 h. and 18 h. respectively, and the numerals 

 affixed beside the points give the corresponding atmospheric pressure 

 (in mm. Hg) at the centre. 



Fig. I. 



On examining the mareograms at each station it was found that 

 conspicuous undulations of longer periods, ranging from 5m-6m to 30m 

 (proper oscillations of bays), generally began six to twelve hours before 

 the arrival of the centre of the cyclone, whereas conspicuous undulations 



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