¶ … Dip in Salinity at the Equator The objective of this study is to examine the possible cause of the dip in salinity around the equator and to answer the question of whether it could be argued that higher temperature causes more evaporation from the ocean surface, which, in turn results in higher salinity content.

Salinity is defined as "the total amount of solid material dissolved in water" and it is reported as well that salinity is generally expressed in terms of percentage. The substances dissolved in seawater are small numbers and are expressed "in parts per thousand." (Lutgen and Tarbuck, 2011) The majority of the salt in seawater is reported as "sodium chloride" or table salt. (Lutgen and Tarbuck, 2011) Seawater salinity is stated at 35%. (Lutgen and Tarbuck, 2011) Sources of salts in the sea include rocks when they are chemically worn and the interior of the Earth occurring in volcanic eruptions as well as a process called outgassing....

(Lutgen and Tarbuck, 2011)
The composition of seawater is reported as having remained "relatively stable for millions of years." (Lutgen and Tarbuck, 2011) The ocean contains three layers including the shallow surface mixed zone, the transition zone and the deep zone. When a layer undergoes temperature change rapidly below the zone or mixing it is referred to as the thermocline. (Lutgen and Tarbuck, 2011, paraphrased) Both the temperature and the salinity of the water change as the ocean depths change. The salinity is varied according to the depth and when a zone of salinity is changing rapidly, it is referred to as the halocline.

It is reported that the density of seawater is affected by two primary factors: (1) salinity; and (2) temperature. (Lutgen and Tarbuck, 2011) Salinity increases dissolved substances and increases in the density of the seawater. However, when the temperature increases the wate3r expands and seawater density is reduced.…