3.3 Ocean Carbon Dynamics and Acidification
2 min read•july 25, 2024
Oceans play a crucial role in regulating Earth's carbon cycle. They absorb CO2 through physical and biological processes, including the and . These mechanisms transport carbon from the surface to deep waters.
, caused by increased , poses significant threats to marine life. It impacts shell-forming organisms, alters ecosystems, and affects coral reefs. Understanding is vital for grasping global carbon dynamics and climate change impacts.
Ocean Carbon Dynamics
Carbon pumps in oceans
Top images from around the web for Carbon pumps in oceans
Ocean Acidification: Corrosive waters arrive in the Bering Sea View original
Is this image relevant?
Biological pump - Wikipedia View original
Is this image relevant?
Biological pump - Wikipedia View original
Is this image relevant?
Ocean Acidification: Corrosive waters arrive in the Bering Sea View original
Is this image relevant?
Biological pump - Wikipedia View original
Is this image relevant?
1 of 3
Top images from around the web for Carbon pumps in oceans
Ocean Acidification: Corrosive waters arrive in the Bering Sea View original
Is this image relevant?
Biological pump - Wikipedia View original
Is this image relevant?
Biological pump - Wikipedia View original
Is this image relevant?
Ocean Acidification: Corrosive waters arrive in the Bering Sea View original
Is this image relevant?
Biological pump - Wikipedia View original
Is this image relevant?
1 of 3
- drives CO2 dissolution in cold surface waters and downwelling in polar regions
- Solubility pump dissolves atmospheric CO2 in colder waters (North Atlantic, Southern Ocean)
- transports vertically due to temperature-dependent CO2 solubility
- Biological carbon pump converts inorganic carbon to organic matter through phytoplankton photosynthesis
- Sinking () transports carbon to deep waters
- by bacteria breaks down organic matter, releasing CO2 at depth
- Carbonate counter pump forms calcium carbonate shells (coccolithophores, foraminifera) which sink and dissolve
Ocean acidification and marine impacts
- Ocean acidification occurs as seawater absorbs increasing atmospheric CO2
- Forms :
- Dissociates: , lowering seawater pH
- Marine organism impacts include:
- Reduced in shell-forming species (oysters, mussels)
- Altered growth and reproduction across various taxa
- Food web disruptions as plankton composition shifts
- Coral reef degradation due to reduced
- Physiological stress in fish affecting behavior and sensory abilities
Ocean-Atmosphere Interactions
Oceans as CO2 regulators
- Oceans absorb ~25% of , acting as a major carbon sink
- driven by partial pressure differences between atmosphere and surface waters
- Oceanic carbon storage occurs in:
- (largest reservoir)
- in marine biota and sediments
- Seawater's maintains pH through:
- (limestone) over geological timescales
Oceans for anthropogenic carbon absorption
- Ocean carbon uptake influenced by:
- Air-sea interface area (70% of Earth's surface)
- Wind speed and wave action increasing gas exchange
- Temperature and salinity gradients affecting CO2 solubility
- Surface water saturation state decreasing with , reducing CO2 absorption capacity
- Biological response to elevated CO2 potentially enhancing ()
- include:
- Altered ocean circulation patterns ()
- (phytoplankton community shifts)
- Long-term storage potential through:
- (centuries to millennia)
- (geological timescales)
Key Terms to Review (33)
Air-sea gas exchange: Air-sea gas exchange refers to the process by which gases are transferred between the atmosphere and the ocean's surface. This process is crucial for regulating atmospheric concentrations of gases like carbon dioxide and oxygen, significantly influencing ocean carbon dynamics and impacting acidification as well as broader open ocean biogeochemical cycles.
Anthropogenic co2 emissions: Anthropogenic CO2 emissions refer to carbon dioxide released into the atmosphere as a result of human activities, particularly the burning of fossil fuels, deforestation, and various industrial processes. These emissions significantly contribute to the greenhouse effect, leading to global warming and changes in ocean chemistry. The impact of these emissions is particularly pronounced in ocean systems, affecting marine life and leading to ocean acidification, which disrupts carbonate chemistry essential for organisms such as corals and shellfish.
Aragonite Saturation: Aragonite saturation refers to the concentration of aragonite, a form of calcium carbonate, in seawater that is necessary for marine organisms, particularly shell-forming species, to build their shells. This saturation state is crucial because it indicates the ability of the ocean to provide the carbonate ions needed for calcification processes, which are affected by ocean carbon dynamics and acidification resulting from increased CO2 levels in the atmosphere and oceans.
Biological carbon pump: The biological carbon pump is a process in the ocean that transfers carbon dioxide from the atmosphere into deep ocean waters through the activity of marine organisms. This process involves phytoplankton absorbing CO2 during photosynthesis, which then enters the food web as organic matter, eventually sinking to the ocean floor, thus sequestering carbon for long periods. It plays a crucial role in regulating atmospheric CO2 levels and mitigating climate change.
Buffering Capacity: Buffering capacity is the ability of a solution to resist changes in pH when acids or bases are added. This property is particularly important in the context of ocean systems, as it plays a crucial role in regulating the acidity of seawater, especially in light of increased carbon dioxide levels from human activities. Effective buffering helps maintain the delicate balance of marine ecosystems by preventing drastic shifts in pH that could harm marine life.
Calcification: Calcification is the process by which organisms produce calcium carbonate (CaCO3) to form hard structures such as shells and skeletons. This process plays a crucial role in marine ecosystems, impacting ocean carbon dynamics and the overall health of marine life, particularly in the face of increasing ocean acidification. As carbon dioxide levels rise, changes in seawater chemistry can significantly affect the ability of marine organisms to calcify, influencing their survival and ecological roles.
Carbon pumps in oceans: Carbon pumps in oceans refer to the natural processes that transport carbon from the ocean surface to the deep sea, effectively sequestering carbon dioxide (CO2) and helping to regulate global climate. These pumps play a critical role in controlling atmospheric CO2 levels through biological, physical, and chemical processes, contributing to the ocean's role as a major carbon sink and influencing ocean carbon dynamics and acidification.
Carbonate system equilibrium reactions: Carbonate system equilibrium reactions refer to a series of chemical reactions involving carbon dioxide (CO2), bicarbonate (HCO3-), carbonate (CO32-), and water (H2O) that maintain a balance in the ocean's carbon chemistry. These reactions are crucial in regulating ocean acidity and maintaining pH levels, which are essential for marine life and overall ocean health.
Carbonic acid: Carbonic acid is a weak acid formed when carbon dioxide dissolves in water, represented by the chemical formula H$_2$CO$_3$. It plays a crucial role in regulating pH levels in natural waters and is fundamental to the processes of ocean acidification and the long-term weathering of rocks. This acid contributes to the buffering capacity of oceans and freshwater systems, impacting marine ecosystems and global climate regulation.
CO2 Absorption: CO2 absorption refers to the process by which carbon dioxide is taken up by various systems, particularly by oceans, where it interacts with water to form carbonic acid. This process is crucial for regulating atmospheric CO2 levels and maintaining the balance of carbon in the environment. It plays a significant role in ocean carbon dynamics, affecting both the chemistry and biological processes within marine ecosystems while contributing to ocean acidification.
CO2 Fertilization: CO2 fertilization refers to the enhancement of plant growth and productivity due to increased levels of carbon dioxide (CO2) in the atmosphere. This phenomenon occurs as plants utilize CO2 during photosynthesis, potentially leading to greater biomass production and crop yields, particularly in nutrient-rich environments. However, this process can have complex implications for ecosystems and climate dynamics, especially regarding ocean carbon dynamics and acidification.
Deep Ocean Carbon Sequestration: Deep ocean carbon sequestration refers to the process of capturing and storing carbon dioxide (CO2) in the deep ocean, where it can remain for centuries or longer, thus reducing the concentration of CO2 in the atmosphere. This method leverages the natural ability of the ocean to absorb CO2 from the atmosphere, helping to mitigate climate change by sequestering carbon in a stable environment, which is essential in understanding ocean carbon dynamics and acidification.
Dissolved Inorganic Carbon: Dissolved inorganic carbon (DIC) refers to the sum of all inorganic carbon species present in water, primarily in the form of carbon dioxide (CO2), bicarbonate (HCO3-), and carbonate (CO32-). This term is crucial in understanding ocean carbon dynamics, as it plays a significant role in regulating the ocean's pH and its ability to absorb atmospheric CO2, which is fundamental to the process of ocean acidification.
Dissolved Inorganic Carbon Pool: The dissolved inorganic carbon pool refers to the collection of inorganic carbon compounds present in ocean water, primarily existing as carbon dioxide (CO2), bicarbonate (HCO3-), and carbonate ions (CO32-). This pool plays a crucial role in regulating oceanic pH levels and is fundamental to the ocean's ability to absorb atmospheric CO2, impacting both marine life and global climate.
Feedback Mechanisms: Feedback mechanisms are processes that regulate systems by amplifying or diminishing the effects of changes within those systems. They play a crucial role in maintaining balance and stability in various environmental and biological contexts, influencing how systems respond to internal and external stimuli. These mechanisms can either be positive, leading to further changes, or negative, promoting stability, which is essential for understanding complex interactions in natural systems.
Marine ecosystem structure changes: Marine ecosystem structure changes refer to the alterations in the organization and composition of marine communities over time, influenced by both natural and anthropogenic factors. These changes can impact species diversity, habitat availability, and overall ecosystem function, often resulting in shifts that affect food webs and nutrient cycling. Understanding these shifts is crucial for addressing the impacts of climate change and ocean acidification on marine environments.
Marine snow: Marine snow refers to the continuous shower of organic and inorganic particles that fall from the upper layers of the ocean to the deeper parts. This phenomenon plays a critical role in ocean carbon dynamics, as it is a key mechanism through which carbon, nutrients, and energy are transported to the deep sea, thus influencing the global carbon cycle and potentially mitigating the effects of acidification.
Ocean acidification: Ocean acidification refers to the process by which the ocean becomes more acidic due to increased absorption of carbon dioxide (CO2) from the atmosphere. This phenomenon has significant implications for marine ecosystems, carbonate chemistry, and global biogeochemical cycles.
Ocean carbon dynamics: Ocean carbon dynamics refers to the complex processes that govern the movement and transformation of carbon compounds in ocean systems. This includes the absorption of carbon dioxide (CO2) from the atmosphere, the biological uptake of carbon through photosynthesis, and the eventual storage or release of carbon by marine organisms and sediments. These dynamics play a crucial role in regulating global climate and supporting marine ecosystems, while also influencing ocean acidification.
Ocean warming: Ocean warming refers to the increase in ocean temperatures due to climate change, primarily driven by the absorption of greenhouse gases emitted by human activities. This phenomenon has significant impacts on marine ecosystems, ocean carbon dynamics, and the overall health of ocean waters, contributing to issues like acidification and changes in ocean circulation patterns.
Ocean-atmosphere interactions: Ocean-atmosphere interactions refer to the complex exchanges of heat, moisture, and gases between the ocean and the atmosphere that significantly influence climate and weather patterns. These interactions play a crucial role in regulating the Earth's climate system, impacting processes such as carbon cycling and ocean acidification, which are essential for understanding how oceans respond to increasing atmospheric carbon dioxide levels.
Organic Carbon: Organic carbon refers to carbon compounds that are found in living organisms and their remains, including plants, animals, and microorganisms. This form of carbon is crucial in the oceanic ecosystem, as it plays a significant role in carbon cycling, supporting marine life and influencing ocean carbon dynamics and acidification.
Particulate Organic Carbon: Particulate organic carbon (POC) refers to the fraction of organic carbon that is present in solid form within aquatic systems, primarily consisting of small particles derived from living organisms, such as phytoplankton and zooplankton, as well as detrital material from the decomposition of dead organic matter. POC plays a crucial role in the ocean's carbon dynamics, influencing both nutrient cycling and the biological carbon pump, which ultimately affects the ocean's capacity to sequester carbon dioxide and its response to acidification.
PH Levels: pH levels measure the acidity or alkalinity of a solution on a scale from 0 to 14, with 7 being neutral. Understanding pH levels is crucial as they influence chemical reactions, biological processes, and the health of ecosystems in both terrestrial and aquatic environments, especially in the context of carbon dynamics and the impacts of acidification on marine life and soil chemistry.
Physical Carbon Pump: The physical carbon pump refers to the process by which carbon dioxide is absorbed from the atmosphere into the ocean, primarily through the mixing of surface waters with deeper ocean layers. This mechanism plays a critical role in regulating global carbon cycles, as it helps sequester carbon in the deep ocean, thereby reducing atmospheric CO2 levels. The physical carbon pump is closely linked to ocean circulation patterns and temperature gradients, influencing both ocean carbon dynamics and acidification processes.
Primary Production: Primary production refers to the process by which autotrophs, such as plants and phytoplankton, convert inorganic carbon (primarily CO₂) into organic compounds through photosynthesis or chemosynthesis. This process is crucial because it forms the foundation of the food web and affects nutrient cycling, energy flow, and the overall health of ecosystems.
Remineralization: Remineralization is the process by which organic matter, such as dead plants and animals, is broken down by microorganisms, releasing essential nutrients back into the environment in their inorganic forms. This process plays a crucial role in nutrient cycling, ensuring that elements like carbon and phosphorus are made available for biological uptake, which is vital for the health of ecosystems.
Sedimentary Carbonate Formation: Sedimentary carbonate formation refers to the geological process through which carbonate minerals, primarily calcite and aragonite, precipitate from seawater and accumulate in sedimentary environments. This process plays a crucial role in the global carbon cycle, as it sequesters carbon dioxide from the atmosphere and ocean, influencing both ocean chemistry and climate regulation.
Shellfish vulnerability: Shellfish vulnerability refers to the increased susceptibility of shellfish populations to environmental stressors, particularly due to changes in ocean chemistry and temperature. This vulnerability is significantly influenced by ocean acidification and the resulting impact on calcifying organisms, which includes many species of shellfish. As the oceans absorb excess carbon dioxide, the pH levels drop, leading to difficulties for shellfish in maintaining their calcium carbonate structures.
Solubility Pump: The solubility pump is a process in the ocean that describes how carbon dioxide (CO2) is absorbed by seawater and transported to deeper ocean layers. This natural phenomenon plays a vital role in regulating atmospheric CO2 levels and thus impacts climate change. The solubility pump works through physical and chemical processes that enhance the dissolution of CO2 in cold, high-latitude waters, which then contributes to the ocean's ability to store carbon over long periods.
Thermocline Pump: The thermocline pump refers to the process by which water layers in the ocean are separated by temperature gradients, leading to the movement of carbon and other nutrients from the surface to deeper waters. This phenomenon plays a crucial role in ocean carbon dynamics, as it helps transport organic matter and influences the overall carbon cycling within marine ecosystems. Understanding the thermocline pump is essential for comprehending how oceans absorb carbon dioxide and its implications for ocean acidification.
Thermohaline Circulation: Thermohaline circulation refers to the large-scale movement of ocean water driven by differences in temperature (thermo) and salinity (haline). This circulation plays a crucial role in regulating Earth's climate by distributing heat and influencing the carbon cycle, particularly in the context of ocean carbon dynamics and acidification.
Weathering of Carbonate Rocks: Weathering of carbonate rocks refers to the process by which carbonates, such as limestone and dolomite, are broken down through physical and chemical processes. This weathering plays a crucial role in the cycling of carbon and affects ocean chemistry, particularly in relation to acidification and carbonate dissolution, influencing marine ecosystems and global carbon dynamics.