21 



However, there is no part of the open sea for which the norr-al 

 surface te-nperature at any season, or the normal seasonal variations 

 are yet known in the detail demanded fox the solution of nian^r ■rress- 

 ing problems. And to trace the irregular fluctuations that exert 

 wide reaching effects within the sea and in the atmosphere, but of 

 whose amplitudes we, as yet, kno?; very little, is one of the .nost 

 urgent tasks tha.t now face the oceanographer. Here are formidable 

 undertakings, for they required the collection of great nurn.bers of 

 records over a wide range of localities, with their subsequent 

 analysis. But no technical difficulty is involved. 



Owing to the facts that an accurate and simple method of measur- 

 ing the salinity is a recent development, and that appreciation of 

 the real importance of a knowledge of this feature of the water is 

 of recent growth, it was not until 1923 that an approximately 

 adequate picture of the mean annual salinity of the surface of the 

 oceans as a whole could be attemptedo And even this most recent 

 chart has necessaril3'- been combined for different seasons in different 

 parts of the picture, and from data spread over so m^.ny years that 

 not all parts of it are comparable. Parthermore, important gaps 

 still remain to be filled for the moan state of the surface for the 

 year as a whole over considerable areas, x;hile much more must yet be 

 done before seasonal charts of the salinity can be even roughly 

 constructed for any one of the ocean basins. 



For example, all the measurements that have yet been made of the 

 salinity of the Arctic extensions of the Atlantic, (including the 

 Baffin's Bay source of the Labrador current, and. the waters north 

 of North America) have been for the sum^nor months, Neither are 

 winter records availab'J.e for the off-shore parts of the Gulf of St, 

 Lawrence, nor has o.nytning yet been published on the salinity of 

 Hudson's Bay, The mean state and seasonal variations still offer 

 an equally attractive problem all along the Atlantic shelf of the 

 United States south of Ghesayeake Bay, in the Caribbean, in the Gulf 

 of Mexico, and in the outflow from the latter through the straits 

 of Florida; Information essential for understanding the secular 

 shifts in the Gulf Stream drift. Knowledge ot the alterations that 

 the highly saline water of the Sargasso Sea undergoes as it drifts 

 outward from its center of concentration, with more detailed knov;- 

 ledge of the seasonal fluctuations in the African side that are 

 associated mth the seasonal migrations of the trade wind belts to 

 north and south, is needed D'^-fore we can reconstruct the inter- 

 movements of the surface waters in the tropical belt of the Atlantic, 



Did we know as much about the salinity of the water off iorocco 

 as we do of its temperature, we could better ^udge the importance 

 (in the general Atlantic complex) of the water that wells up there 

 from the deeps, in bringing up a supply of dissolved nutrient:; to 

 help maintain the fertility of the surface strat'xn for pla.nt life. 

 The seasonal alterations in the salinity of the surface around South 

 Africa, reflecting the alternate contractions and e.-spansions of the 

 warm Alguhlas a.nd co3d Benguela currents, also remuin to be plotted 

 in detail. And the only general :parts of the Pacific for which an 

 approximately adequate understanding of the seasonal cycJ.e of 

 salinity of the surface has yet been gained are the coast v;aters 

 along California in the one side, Japanese waters and the Javan Sea 

 in the other. 



