Oceanic carbon

Definition

Oceanic carbon refers to the carbon stored in the ocean, which is a major reservoir in the global carbon cycle. This carbon exists in various forms, including dissolved inorganic carbon (DIC), organic carbon from marine organisms, and particulate carbon from organic matter decomposition. The ocean plays a crucial role in regulating atmospheric CO2 levels, influencing climate and biological processes on Earth.

5 Must Know Facts For Your Next Test

1. The ocean holds about 38,000 gigatons of carbon, making it the largest active carbon reservoir on Earth.
2. Oceanic carbon exchange with the atmosphere occurs primarily through physical processes like diffusion and biological processes such as photosynthesis and respiration.
3. Marine phytoplankton play a vital role in capturing atmospheric CO2 and converting it into organic matter through photosynthesis.
4. Ocean acidification, resulting from increased CO2 absorption by seawater, poses a threat to marine ecosystems by impacting organisms like corals and shellfish that rely on calcium carbonate.
5. The ocean's ability to sequester carbon is influenced by factors such as temperature, salinity, and nutrient availability, affecting its overall efficiency in mitigating climate change.

Review Questions

• How does oceanic carbon contribute to the regulation of atmospheric CO2 levels?
  • Oceanic carbon acts as a significant buffer for atmospheric CO2 levels by absorbing excess carbon from the atmosphere. This occurs through processes such as diffusion and biological uptake by marine organisms. By sequestering CO2 in various forms within the ocean, such as dissolved inorganic carbon and organic matter, the ocean plays a crucial role in moderating climate change and maintaining a stable environment for life on Earth.
• Discuss the impact of ocean acidification on marine ecosystems and its connection to oceanic carbon storage.
  • Ocean acidification occurs when increased levels of CO2 are absorbed by seawater, leading to lower pH levels. This process significantly impacts marine ecosystems, particularly organisms like corals and shellfish that rely on calcium carbonate for their structures. As these organisms struggle to maintain their shells and skeletons in more acidic waters, the overall biodiversity and health of marine ecosystems decline. This loss can reduce the ocean's capacity to store carbon over time, disrupting both local ecosystems and global carbon cycling.
• Evaluate how changes in oceanic carbon levels can influence global climate patterns and feedback mechanisms.
  • Changes in oceanic carbon levels can have profound effects on global climate patterns through feedback mechanisms. For example, an increase in atmospheric CO2 leads to higher ocean temperatures, which can decrease the solubility of CO2 in seawater. This situation not only reduces the ocean's capacity to sequester further CO2 but also intensifies climate change effects such as extreme weather events. Additionally, shifts in oceanic carbon can alter marine food webs and biogeochemical cycles, leading to broader ecological impacts that further exacerbate climate change.

Related terms

Carbon Cycle: The continuous movement of carbon among the atmosphere, oceans, soil, plants, and animals, essential for maintaining life on Earth.

Dissolved Inorganic Carbon (DIC): The form of carbon found in water as bicarbonate, carbonate, and dissolved CO2, which is critical for marine chemistry and biological processes.

Biological Pump: A process where marine organisms capture CO2 during photosynthesis and transport it to deeper ocean layers through the decomposition of organic matter.