Understanding Ocean Acidification

Understanding Ocean

Acidification

Climate Chemistry

What is ocean acidification?

●Ocean acidification is a phenomenon caused by the absorption of
carbon dioxide (CO2) from the atmosphere into the surface waters
of the ocean.

●This process leads to changes in the chemical composition of
seawater, resulting in a decrease in pH and alterations in carbonate
chemistry.

●Understanding the chemical processes underlying ocean acidification is
crucial for comprehending its impacts on marine ecosystems and
biodiversity.

Carbon Dioxide (CO2) Dissolution

●CO2 from the atmosphere dissolves into ocean waters.

Carbonic Acid Formation

●CO2 reacts with water to
form carbonic acid (H2CO3).

●CO2 + H2O ⇌ H2CO3

a.Note: Reversible process
with equilibrium arrows.

Hydrogen Ion (H+) Release and
Bicarbonate Formation

●Carbonic acid (H2CO3)
dissociates into hydrogen
ions (H+) and bicarbonate
ions (HCO3-).

pH Change

●Increased dissolved
CO2 leads to carbonic
acid formation and
decreased seawater
pH.

Carbonate Ion (CO32-) Formation

●Bicarbonate ions further react to form carbonate ions (CO3^2-).

Impact on Calcium Carbonate Structures

●Decrease in
carbonate ions
affects calcifying
organisms' ability to
form calcium
carbonate structures.

Shell Dissolution

●Calcium carbonate structures dissolve in acidic seawater.

Effects on Marine Life

●Ocean acidification affects
marine organisms' ability to
build and maintain calcium
carbonate structures.

- This can cause a chain
reaction that will travel up the
food chain

Equilibrium Arrows

●Ocean acidification is a
dynamic process
influenced by reversible
reactions.