Difference in density
As we all know, the density of sea water varies from place to place according to its temperature and proportion of salinity. The density increases with an increase in salinity and decreases with a decrease in salinity. But when the temperature increases, density decreases and when the temperature decreases density increases.
This increase and decrease in density due to the differences in temperature and salinity causes the water to move from one place to another. Such a movements of water due to the differences in density as a function of water temperature and salinity is called as the Thermohaline Circulation.
The earth’s rotation
Earth’s rotation causes Coriolis force which deflects the air to its right in the northern hemisphere and to its left in the southern hemisphere-Ferrel’s Law. Similarly, oceans water also affected by the Coriolis force and follows the Ferrel’s Law.
The winds like trade winds and westerlies drive the ocean water in a steady flow in front of them. When the direction of the winds changes, the direction of the current also gets changed.CGPCS Notes brings Prelims and Mains programs for CGPCS Prelims and CGPCS Mains Exam preparation. Various Programs initiated by CGPCS Notes are as follows:-