 |
| Titel |
Observations of changes in the dissolved CO2 system in the North Sea, in four summers of the 2001-2011 decade |
| VerfasserIn |
Nicola Clargo, Lesley Salt, Helmuth Thomas, Hein de Baar |
| Konferenz |
EGU General Assembly 2015
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250111768
|
| Publikation (Nr.) |
 EGU/EGU2015-11910.pdf |
|
|
|
|
|
| Zusammenfassung |
| Since the industrial revolution, atmospheric concentrations of carbon dioxide (CO2) have
risen dramatically, largely due to the combustion of fossil fuels, changes in land-use patterns
and the production of cement. The oceans have absorbed a large amount of this CO2, with
resulting impacts on ocean chemistry. Coastal seas play a significant role in the mitigation
of anthropogenic atmospheric CO2 as they contribute approximately 10-30% of
global primary productivity despite accounting for only 7% of the surface area.
The North Sea is a perfect natural laboratory in which to study the CO2 system as
it consists of two biogeochemically distinct regions displaying both oceanic and
relatively coastal behaviour. It has also been identified as a continental shelf pump with
respect to CO2, transporting it to the deeper waters of the North Atlantic. Large scale
forcing has been shown to have a significant impact on the CO2 system over varying
time scales, often masking the effects of anthropogenic influence. Here, we present
data from the North Sea spanning the 2001-2011 decade. In order to investigate
the dynamics of the dissolved CO2 system in this region in the face of climate
change, four basin-wide cruises were conducted during the summers of 2001, 2005,
2008 and 2011. The acquired Dissolved Inorganic Carbon (DIC) and alkalinity data
were then used to fully resolve the carbon system in order to assess trends over the
2001-2011 decade. We find significant interannual variability, but with a consistent,
notable trend in decreasing pH. We found that surface alkalinity remained relatively
constant over the decade, whereas DIC increased, indicating that the pH decline is
DIC-driven. We also found that the partial pressure of CO2 (pCO2) increased faster than
concurrent atmospheric CO2 concentrations, and that the CO2 buffering capacity of the
North Sea decreased over the decade, with implications for future CO2 uptake. |
|
|
|
|
|
|