Ocean water contains salts and gases. Ocean Water Chemistry Ocean water contains salts and gases.

Salinity Salinity: total amount of dissolved salts in a sample of water. Sodium chloride is present in the greatest amount.

Variations in Salinity Avg. salinity is b/t 34-37 ppt. Lower salinity near the ocean’s surface and near the mouths of large rivers. Evaporation increases salinity. Oceans in hot, dry climates have greater salinity. Salinity is also higher near the poles.

Effects of Salinity Ocean water has a lower freezing point than freshwater. Ocean water has a higher density than freshwater. Ocean water has greater buoyancy than freshwater.

Other Ocean Properties Temperature: decreases as depth increases. In other words the deeper you go… the colder it gets! Density: increases with depth. Pressure: increases continuously with depth. Gases: CO2 and O2. O is more plentiful near the surface and in colder waters. O comes from air and algae.

The Water Column Surface Zone: Extends from surface to ~200m. Sunlight can penetrate. Warmest. Thermocline: temperature decreases fast with depth. Deep Water:cold all year even near the tropics.