Salt Budgets of the Ocean

The salinity of seawater is not constant across the globe and is influenced by a complex interplay of processes. The concept of a "salt budget" helps us understand how these processes affect the salinity of different ocean regions.

• Inputs
  • River Runoff: Rivers carry dissolved salts from the land into the ocean.
  • Volcanic Activity: Volcanic eruptions release gases and minerals into the atmosphere, some of which end up in the ocean.
  • Sea Spray: Saltwater droplets carried by wind can contribute to salt deposition.
• Outputs
  • Precipitation: Freshwater from rain and snow dilutes seawater.
  • Sea Ice Formation: When seawater freezes, salt is excluded from the ice, increasing the salinity of the surrounding water.
  • Sedimentation: Some salts are removed from seawater when they precipitate out and settle on the ocean floor.
• Factors Affecting Salinity
  • Evaporation: In regions with high evaporation rates, such as the tropics, salinity increases as water evaporates, leaving behind salts.
  • Precipitation: In regions with high precipitation, salinity decreases as freshwater dilutes the seawater.
  • Ocean Currents: Ocean currents transport salt and water masses around the globe, influencing salinity distribution.
• Importance of Salt Budgets
  • Understanding salt budgets is crucial for understanding ocean circulation patterns and climate variability.
  • Changes in salinity can affect ocean density and therefore influence ocean currents, which play a significant role in regulating Earth's climate.
  • Studying salt budgets helps scientists to assess the potential impacts of climate change on ocean circulation and marine ecosystems.