high concentrations showing no apparent divisions that can readily 

 be ascribed to circulation. Values for the highest concentrations of 

 inorganic phosphate were slightly greater in 1962, while the con- 

 centrations of nitrate and silicate remained about the same in each 

 year but show a more restricted distribution in 1963. 



Weather ship Bravo is located near the midpoint of the Labrador- 

 Greenland section (56.5° N., 51.0° W.) and its daily reports may be 

 used to provide information on the variation in seasonal weather 

 conditions in the Labrador Sea. Data on air and sea temperatures, 

 windspeed and wind direction have been taken from the Northern 

 Hemisphere data tabulations, part II of the synoptic weather maps 

 published daily by the U.S. Weather Bureau. Reduced to mean 

 monthly averages, the sea surface temperatures for January through 

 March of 1963 are lower than for the same period in 1962, as shown 

 in table IX. 



Table IX. Mean Monthly Sea Surface Temperatures, From Daily Reports of Weather 

 Ship "Bravo" (56.5° N., 51.0° W.) 



[In °C.] 



Diflference 

 1962-63 



January. 

 February 

 March--- 



-0.25 

 -0.34 

 -0.34 



Observations at this latitude in February 1962, made by L. V. 

 Worthington on the Erika Dan, under charter to the Woods Hole 

 Oceanographic Institution, show a surface salinity of about 34.79. 

 Assuming the same pressure and salinity conditions for 1963, the lower 

 average sea surface temperature would give a change in density from 

 27.70 (for 1962) to 27.74 (for 1963). It is suggested that this increased 

 density at the surface results in a reduced stability, thus promoting 

 more sinking from the surface and increased formation of North 

 Atlantic deep water in the area.- Wind observations from weather 

 ship Bravo do not indicate any significant difference in either wind- 

 speed or direction for this period in the 2 years. It must be acknowl- 

 edged, however, that conditions still farther north for which data are 

 unavailable would be of yet more importance in producing the water- 

 mass structure seen on this Labrador-Greenland section itself. 



The level of organic phosphorus, which is estimated from the 

 difference between the total and the inorganic phosphorus, can be 

 statistically compared for various levels of the water column by 

 grouping in a frequency distribution by depth intervals. The number 

 of determinations (n), the mean value (x), variance (s^), standard 

 deviation (s), and standard error of estimate {s/^/n) for 1,000-meter 



2 The relative stability may be given as AaiXW^lAD (in meters). For the present purpose, it may be 

 assumed that there was no change in either year for the deeper water density to which the surface value is 

 compared. 



69 



