Chemical Oceanography
Properties that water contains are the result from the polar structure of the water molecule. When salt is disolved into the water, the water's density increases and depress' both the temperature of the maximum density and the freezing point. The ocean contains up to 97% of the water in the hydrological cycle that circulates. The time of the water spent in the ocean is measured in thusands of years and in the atmosphere, it is measured in days.
The average amount of salt in sea water is close to 35 parts per thousand by weight. Eleven elements make up 99.9% of the disolved minerals. They are Na+, SO42-, Mg2+, Ca2+, K+, HCO3-, Br-, H2BO3-, Sr2-, and F-. The amount of salt in the water differs from place to place, but all generally contain the same amount of elements. Evaporation and precipitation also change the amount of salt in the water. Some of the major elements are comercially extracted from the water also.
Rainwater is seawater, but is diluted because aerosols carry the salts in the water into the atmosphere where it provides nuclei for rain formation. The elements disolved in rivers are the result of rock weathering and foriegn objects. Much of the sodium in the rivers is from recycled sea salt. When rivers have excessive amounts of chloride, bromide, andd sulfate, it is most likely because of volcanic gases.
There are 11 major dissolved constituents of sea water with concentrations greater then one part per million by weight. Phosphate and nitrate are minor constituents and essential nutrients. Silca is also a biolimiting nutrient. Carbon is essential to all life, but is so abundant in seawater that its involvement in biological production makes only a small difference to its concentration. Calcium is used to make calcium carbonate skeletons and shells, but like carbon it is so abundant that it makes little difference. Both carbon and calcium are both bio-intermediate constituents which means their concentrations are uneffected by biological activity.
This is basically what chemical oceanography is about; the ocean and its components. If you would like to learn more, go to www.sos.bangor.ac.uk/netstudy/o1p02/o1p02top.html