Papers in Marine Biology and Oceanography, Suppl. to vol. 3 of Deep-Sea Research, pp. 331-334. 



Characteristics of surface water at Weather Ship J * 



By R. B. Montgomery 

 Chesapeake Bay Institute, The Johns Hopkins University, BaUimore, Maryland 



Summary— Surface temperature and salinity observed 15 times a month for 3 years at Weather 

 Ship J, west of Ireland, are presented in two-dimensional frequency distribution on a temperature- 

 salinity diagram. 



The temperature-salinity diagram was introduced by Helland-Hansen (1916). 

 Helland-Hansen and Nansen (1926) and others have used it as a scatter diagram 

 for representing a large number of discrete, non-uniformly spaced observations. 

 The purpose of the present paper is to demonstrate the suitability of the tempcrature- 

 saUnity diagram for quantitative representation of frequency distribution of water 

 characteristics. A uniform series of data is used to prepare a diagram for a fixed 

 point in the ocean. 



o|o o|o 0|o ^,0 

 ^O ^0 ^O ^qI 



Fig 1 Annualtemperature-salinity diagram for surface water at Weather Ship J. 1948-1950. Num- 

 ber of occurrences per thousand is entered in each square (blank squares ha\e no occurrence). Heavy 

 frequency isopleth (2U per miile) surrounds 51 percent of occurrences, hnc frequency isoplcth (54 

 per mille) surrounds 89 per cent. Monthly means are plotted as dots, each month idcntiticd by a 

 Roman numeral. Anomaly of specific volume is shown by the family of cur\es. 



* Contribution No 25 from the Chesapeake Bay Institute. This study was supported in part by 

 the Office of Naval Research and by a research grant from the National Science Foundation. 



331 



