The average annual heat balance of the North Pacific Ocean and its relation to ocean circulation

The heat exchange at the surface of the Pacific Ocean north of 20°S has been calculated from climatic data for the period 1947–1960, averaged over 2° squares and months. The maps of the different components of the heat exchange show much more detail and a closer relation to climatic regions than those by other authors. The integral of the total heat exchange indicates that the North Pacific gains heat at a rate of 3×1014 cal/sec, which is probably one of the reasons that no deep water is formed in this ocean basin. This heat gain is compensated by deep water ascending with an average velocity of 1.25×10−5 cm/sec. The water balance of the North Pacific is maintained by an outflow of warm surface water at the rate of 8 million m3/sec, which takes place partly through the Indonesian waters and partly in the eastern tropical Pacific from the countercurrent to the south equatorial current. The North Pacific gains heat chiefly along its eastern side and south of 25°N; the main heat loss occurs in the Kuroshio region. The average temperature distribution in the range of the subtropical anticyclone is maintained in the presence of these heat sources and sinks by a horizontal circulation of the order of 10 million m3/sec, occupying only a shallow surface layer.