Section 2: The chemical signature of life in the ocean
1.1 Seasonal Cycle
1.2 Stoichiometry
- Redfield Stoichiometry
- Redfield, A.C. On The Proportions Of Organic Derivatives In Sea Water And Their Relation To The Composition Of Plankton. James Johnstone Memorial Volume, 176–192 (Liverpool University Press, 1934).
1.3 Global Carbon Cycle and box models
- The ocean carbon cycle exists within the larger global carbon cycle
- It is important to have a grasp of the relative magnitude of different fluxes / reservoirs of carbon in the earth system
Natural vs. Anthropogenic vs. Contemporary
- Definitions
- Contemporary = Natural + Anthropogenic
- Natural: pre-industrial carbon fluxes
- Anthropogenic: This can be tricky. “Anthropogenic” carbon is not whether or not an individual “C” atom came from fossil fuels, it is the change in the C storage or C flux between pre-anthropogenic times and present day.
- Note about direct or indirect changes, include link to Hauck paper
Current anthropogenic fluxes:
- Emissions: 11 Pg C yr-1
- Atmospheric: 5 Pg C yr-1
- Ocean uptake: 2.5 Pg C yr-1
- Approximately: -0.6 Natural outgassing + 2.5 anthropogenic uptake = 1.9 Contemporary Ocean uptake
Current contemporary fluxes:
- Units: Pg C yr-1
- Solubility pump: 264 down, 275 up
- Bio pump (ANCP): ~13
- Biological carbon export is ~5-10% the magnitude of the solubility pump
- Significant uncertainty in control / response to changes
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Provides an avenue for long-term burial
- Sediment: 0.2
Question, Does biological carbon pump contribute to ocean’s uptake of anthropogenic carbon?
Sidebar - Global Carbon Budget Units:
- You will often see units of either PgC or Gigatonne C.
- You will also see either C or CO2.
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