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| Titel |
Impact of vertical mixing on sea surface pCO2 in temperate seasonally stratified shelf seas |
| VerfasserIn |
Tom Rippeth, Ben Lincoln, Hilary Kennedy, Matthew Palmer, Jonathan Sharples, Charlotte Williams |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250087385
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| Publikation (Nr.) |
 EGU/EGU2014-1428.pdf |
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| Zusammenfassung |
| A key parameter in determining the exchange of CO2 across the ocean-atmosphere interface
is the sea surface pCO2. Temperate seasonally stratified shelf seas are thought to represent a
significant sink for atmospheric CO2. Here an analytical model is used to quantify the
impact of vertical mixing across the seasonal thermocline on the sea surface value of
pCO2. The model includes the impacts of the resultant dissolved inorganic carbon,
heat, salt and alkalinity fluxes on the solubility of CO2 and also the effect of the
inorganic carbon sink created by the primary production fuelled by the flux of limiting
nutrient. The results indicate that diapycnal mixing drives a modest but continuous
change in the sea surface value of pCO2 of order 1-10 matm per day. In quantifying
the individual impacts of the fluxes of the different parameters we find that the
impact of the fluxes of DIC and nitrate fluxes dominate, with both the direction
and magnitude of the change in sea surface pCO2 strongly dependent on the C:N
uptake ratio in primary production. Whilst the smaller impacts of the heat and salt
fluxes tend to compensate for one another other at mid-shelf locations, the heat flux
dominates close to the shelf break. The analysis highlights the importance of the
accurate parameterisation of the C:N uptake rate by primary production, the surface
mixed layer depth and the TKE dissipation rate within the seasonal thermocline in
models to be used to predict the air-sea exchange of carbon dioxide in these regimes. |
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