The factors, which affect the distribution of temperature of ocean water are as follows:
- Latitude: The temperature of surface water decreases from the equator towards the poles because the amount of insolation decreases pole-ward.
- Unequal distribution of land and water: The oceans in the northern hemisphere receive more heat due to their contact with larger extent of land than the oceans in the southern hemisphere.
- Prevailing wind: The winds blowing from the land towards the oceans drive warm surface water
away from the coast resulting in the upwelling of cold water from below. Contrary to this, the
onshore winds pile up warm water near the coast and this raises the temperature.
- Ocean currents: Warm ocean currents raise the temperature in cold areas while the cold currents
decrease the temperature in warm ocean areas. For example: Gulf stream (warm current) raises the
temperature near the eastern coast of North America.
- Enclosed sea: The enclosed seas in the low latitudes record relatively higher temperature than the
open seas; whereas the enclosed seas in the high latitudes have lower temperature than the open