IX.—Specific Gravities and Oceanic Circulation

Abstract

In the report on Oceanic Circulation, based on the observations made on board H.M.S. “Challenger,” and other observations, which was published in the beginning of 1895 as an Appendix in the Summary of Results, Second Part Challenger Reports, the specific gravities dealt with were all at the standard temperature of 60° Fahr., the standard density being that of distilled water at 39°·2 (4° C). By this method of treatment the question of the salinity or saltness of the water is approximately stated, unquestionably one of the most important questions affecting the physics of the ocean. But the movement of the water, or oceanic circulation, as resulting from different densities, can only be represented by stating, not the specific gravity reduced to the uniform temperature of 60°, but the specific gravity at the observed temperature at all points in the ocean at which observations are made. In this paper these specific gravities are viewed in their relations to the circulation of the waters of the ocean.