Ocean - Sinks Flashcards
What is the most prominent feature of ocean carbon sinks?
Phytoplankton absorbing up to 50%
What are the two major mechanisms of carbon sinkage in oceans?
Biological Pumps and Soubulity Pumps
Biological Pumps
The fixing of inorganic carbon into organic matter by PS with then transport into deep oceans.
Solubility Pumps
Transportaiton of carbon from dissolved inorganic carbon from ocean surface to its interior.
Ocean Acidification
The reducition in pH of oceans over periods of time primarily by CO2 uptake.
Euphotic Zone
The zone where plankton grow on the surface of oceans.
What are the three main constiuents of the BIological Pump?
Phytoplankton, Consumers and Bacteria
What is the structure of the BIological Pump?
Vertical Distribution of carbon by surface partial pressure of CO2.
Partial Pressure
The pressure of a gas when in a container with other gases also exerting pressure.
What does the B-Pump vertical distribution determine?
The air/water interface exchange of CO2
What is the role of phytoplankton?
Lower partial pressure of CO2 in upper zones through photosynthesis.
How does phytoplankton photosynthesis decrease CO2 levels in the atmosphere?
It removes CO2 in upper ocean levels allowing diffusive forces from the atmosphere to disseminate
What happens to organic carbon build up in the euphotic layer?
Processing by microbes/zooplankton to fecal matter.
How is processed organic carbon transported to lower ones?
Vertical migration of zooplankton.
Why is organic matter the primary mediator of CO2 sequestration?
As inorganic matter is usually recycled by upper level bacteria.
Why does dissolved organic carbon accumulate in the upper levels?
Microves do not immediately mineralise it.
What is dissolved inorganic carbon formed from?
Dissolved organic carbon by respiration.
Why does DIC increase with depth?
Increased respiration and decreased photosynthesis?
How does Thermohaline Circulation relate to DIC?
It returns low level DIC thousands of years after deposition.
Ballast Materials
These consitute the particle leaving the ocean by sinking, denser than sea water and mostly organic.
Why is particle aggregation important in CO2 deposition?
Can lead to larger particle formation from smaller ones leading to sinking.
Whay is CO2 vertical flux dependent on?
Phytoplankton Blooms
Marine Snow
Fecal Pallets
Marine Snow
Dense composition of organic aggregates originatiing from phytodetritus.
What is an example of marine snow?
Appendicularians secreting house structures composed of organic material like cellulose which are rapidly discharged throughout the day.
What are Aggregates?
The mass sedimentation by phytoplankton blooms determines by adhesive capabilites probabalistic of phytoplankton collision.
What are the three main constiuentes of marine phytoplankton?
Cyanobacteria (Nitrogen Fixers)
Diatoms (Sillcifiers)
Coccolithophores(Calcifiers)
How do different species of marine phytoplankton differ?
Different sinking velocities due to cell wall composition structure, size, feeding habits etc.
What is an example of size differnetiation in phytoplankton?
Cyanobacteria are smaller with lower sinking velocities thus have less carbon export potential from surface layers
What is phytoplankton growth dependent on?
Temperatyre, light competition and nutrients.
Why is phytoplankton physilogy and stoichiochemistry important?
It determines nutritional value recieved by consumers thus energy flow.
Why is CO2 level increase dependent on the species?
Each species has varying levels of CO2 concentration mechanisms surrounding the Rubisco Enzyme.
Why might the bicarbonate/co2 ratio change benefit organisms?
Those utilising only CO2 have increase growth opposed to those using bicarbonate.
Why are larger diatoms more affected by CO2 increase over smalelr ones?
Smaller cells have larger surface area per unit volume supporting more diffusive uptake, whilst larger diatoms rely more of CO2 concentraiton mechanisms
CO2 Concentrating Mechanisms
Elevation of CO2 saturation near Rubisco to increase photosynthetic CO2 efficiency.
