Temperature and salinity (the amount of dissolved salts in the water) affect the density of the water. Ocean salinity differs by small numbers, so oceanographers need to be accurate when measuring salinity. Changes in density caused by wind and currents at the surface affects the deep-ocean currents.
The salinity of ocean water can be determined by measuring the conductivity of the water. The characteristics of water such as salinity, depth, temperature, density can be defined by the instrument called Conductivity Temperature Depth instrument. Using this technique oceanographers determine the salinity of water.
