Factors Affecting The Temperature Of Ocean Waters
The average temperature of ocean as a whole is 3-4 degree Celsius. This is because the variations in temperature occur in the upper 200 fathoms up to which sunlight penetrates. Beyond this, the temperature is more or less constant across all the oceans. It is estimated that over 80 percent of all ocean waters have a temperature between 1.5° and 4.6°C.
- Like landmasses, ocean water varies in temperature from place to place both at the surface and at great depths. Since water warms up and cools down much more slowly than the land, the annual range of temperature in any part of the ocean is very small.
- Following factors are responsible for the variations in temperatures of ocean waters:-
Latitude:
- The temperature of surface water decreases from the equator towards the poles because the amount of insolation decreases poleward.
Land Water differential:
- The oceans in the northern hemisphere receive more heat due to their contact with a larger extent of land than the oceans in the southern hemisphere.
Prevailing Winds:
- 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. It results in the longitudinal variation in the temperature. Contrary to this, the onshore winds pile up warm water near the coast and this raises the temperature.
Ocean Currents:
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Warm ocean currents raise the temperature in cold areas while the cold currents decrease the temperature in warm ocean areas.
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The enclosed seas in the low latitudes record relatively higher temperature than the open seas; whereas the enclosed seas in the high latitudes have a lower temperature than the open seas.