Temperature in oceanic water usually reduces along with the increasing latitudes. An extensive form of the horizontal distribution of the temperature of oceanic water is being presented as follows:
It is clear from the above table, that the temperature generally decreases towards the poles. In the Atlantic Ocean only, after the slightest increase in temperature between 20 degrees and 30 degrees north latitudes, the sequence of decline again continues. Due to less expansion of 20 to 30 degree latitudes in the Indian Ocean, the rate of temperature decline is very low. Thus, the rate of decline in temperature towards the poles is half degree Celsius per latitude.
Vertical Distribution of Temperature: The vertical distribution of ocean temperature is dependent on the amount of heat absorption, its horizontal displacement by water current and vertical motion of water. In ocean water, the sunrays provide heat by entering down to a depth of 25 meters. After this depth, the effect of sun’s radiation becomes negligible.
Thus, due to insolation, the surface water of ocean becomes hotter. In polar regions, the cold water being heavy settles down at the bottom. Due to being light, the warm water of the equatorial regions flows towards the polar regions by surface currents. In this way, the transmission of the temperature of oceanic water occurs.
From the surface of oceanic water towards the depth, the temperature declines with rapid speed till the depth of 2000 meters. After that depth, the rate of temperature decline becomes very low. This fact is visible in the open seas. In partially surrounded oceans like the Mediterranean Sea and the Red Sea, the decline in temperature is lower than that in the nearby open oceans.
