Answer: They create density differences that cause dense deepwater currents to flow toward the equator where they displace less dense, warmer water above them.
The temperature and salinity has a major impact on water current of oceanic water. The warm water is usually less denser than colder water, so it remains at the surface of water body, whereas the colder water being more in density remain in a depth. The salinity of cold water is more than the warm water.
According to the above explanation, they create density differences that cause dense deepwater currents to flow toward the equator where they displace less dense, warmer water above them is the correct explanation.