OCEAN WATERS AND THEIR CIRCULATION

OCEAN WATERS AND THEIR CIRCULATION
The temperature and salinity are two important properties of the ocean water, which determine the movements of large masses of water, their characteristics and the types, and' also the types of marine flora and fauna.

Temperature decreases according to the increasing depth of the ocean. In general, temperature in ocean waters varies from below -5°C to over 33 "c. In the oceans, temperature of the surface water varies from one part to another. Wa!er is hottest near the equator and temperature gradually decreases polewards. The annual range of tem­perature is greater in the Atlantic than in the Pacific Ocean due to the difference in their size. The highest temperatures are recorded in the enclosed tropical areas. For example, the average summer temperature of the surface water of the Red Sea is about 30 "c.

The amount of salinity also varies from one part of 1200 the ocean to another" The areas of the highest salinity are found near the tropics. In the Atlantic Ocean, the salinity near the tropics is about 37 per cent. From the tropical areas of the oceans, the salinity decreases both towards the equator and towards the poles. In the polar seas, there is less salinity - between 20 per cent and 32 per cent - due to very low amount of evaporation (in the tropics, there is active evaporation owing to clear skies).