 |
| Titel |
Modelling changes in eastern Mediterranean deep water formation for the early Holocene |
| VerfasserIn |
F. Adloff, U. Mikolajewicz |
| Konferenz |
EGU General Assembly 2009
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250028404
|
|
|
|
|
|
| Zusammenfassung |
| During the early Holocene, abrupt changes in the eastern Mediterranean deep waters
properties are reflected in the occurrence of organic-rich marine sediment layers
called sapropels. These layers develop in response to reduced oxygen availability in
bottom waters and are correlated with the precession cycle. A possible explanation is
that a precession-induced increase in the amount of freshwater input leads to a
reduction of the deep water ventilation and could allow the formation of those organic
layers.
In this study, we investigate the effect of the orbitally-induced changes in freshwater
budget on deep water formation for 6000 and 9000 years before present. How is the
Mediterranean thermohaline circulation affected?
To answer this question, we set up a regional version of the general ocean circulation
model MPIOM for the Mediterranean (26 km horizontal resolution). We forced the model
with atmospheric data derived from quasi-equilibrium time slice simulations with the coupled
atmosphere-ocean-dynamical vegetation model ECHAM5/MPIOM/LPJ.
A series of long sensitivity experiments (>250 years) is used to analyze the impact of
different sources of additional freshwater (like enhanced runoff from the Nile or larger inflow
from the Black Sea) on the deep water formation and the ventilation of the eastern
Mediterranean basin.
Preliminary results from the ongoing simulations show that the enhanced runoff from the
Nile leads to a weakening of the Levantine intermediate water formation. Further results of
these simulations will be presented. |
|
|
|
|
|