 |
| Titel |
Fingerprints of changes in the terrestrial carbon cycle in response to large reorganizations in ocean circulation |
| VerfasserIn |
Anil Bozbiyik, Marco Steinacher, Fortunat Joos, Thomas F. Stocker |
| Konferenz |
EGU General Assembly 2011
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250055032
|
|
|
|
|
|
| Zusammenfassung |
| CO2 and carbon cycle changes in the land, ocean and atmosphere are investigated using the
comprehensive carbon cycle-climate model NCAR CSM1.4-carbon. Ensemble simulations
are forced with freshwater perturbations applied at the North Atlantic and Southern Ocean
deep water formation sites under pre-industrial climate conditions. As a result, the Atlantic
Meridional Overturning Circulation reduces in each experiment to varying degrees. The
physical climate fields show changes that are well documented in the literature but there is a
clear distinction between northern and southern perturbations. Changes in the physical
variables affect, in return, the land and ocean biogeochemical cycles and cause a
reduction, or an increase, in the atmospheric CO2 by up to 20 ppmv, depending on
the location of the perturbation. In the case of a North Atlantic perturbation, the
land biosphere reacts with a strong reduction in carbon stocks in some tropical
locations and in high northern latitudes. In contrast, land carbon stocks tend to increase
in response to a southern perturbation. The ocean is generally a sink of carbon
although large re-organizations occur throughout various basins. The response of the
land biosphere is strongest in the tropical regions due to a shift of the Intertropical
Convergence Zone. The carbon fingerprints of this shift, either to the south or to the
north depending on where the freshwater is applied, can be found most clearly
in South America. For this reason, a compilation of various paleoclimate proxy
records of Younger Dryas precipitation changes are compared with our model results. |
|
|
|
|
|
|