INTRO TO MARINE SCIENCE - Lecture 8

Chemistry of Seawater: Gases Trace Metals and Nutrients

Water is a _________________.

universal solvent

Concentrations are influenced by:

• exchange with the atmosphere

• inputs from rivers

• biological activity

• exchange with sediment

Abundant gases in atmosphere and ocean:

• nitrogen

• oxygen

• carbon dioxide

Saturation concentration

the maximum amount of gas that can be held in a solution

Solubility of gases in water changes with:

• temperature

• salinity

• pressure

Solubility increases when:

• temperature decreases

• salinity decreases

• pressure increases

colder and less salty water holds ____________.

more gas

higher pressure water holds more gas than _____________________.

lower pressure water

Gas solubility

the ability of gas to be dissolved and go into solution

Pycnocline

layer of rapidly changing density

• barrier to vertical mixing

Oxygen Minimum

• high biological activity

• low mixing

Major inorganic limiting nutrients for phytoplankton growth

• nitrogen

• phosphorus