Modeling Mediterranean Ocean climate of the Last Glacial Maximum

Abstract

Abstract.A regional ocean general circulation model of the Mediterranean is used to study the climate of the Last Glacial Maximum. The atmospheric forcing for these simulations has been derived from simulations with an atmospheric general circulation model, which in turn was forced with surface conditions from a coarse resolution earth system model. The model is successful in reproducing the general patterns of reconstructed sea surface temperature anomalies with the strongest cooling in summer in the northwestern Mediterranean and weak cooling in the Levantine, although the model underestimates the extent of the summer cooling in the western Mediterranean. However, there is a strong vertical gradient associated with this pattern of summer cooling, which makes the comparison with reconstructions complicated. The exchange with the Atlantic is decreased to roughly one half of its present value, which can be explained by the shallower Strait of Gibraltar as a consequence of lower global sea level. This reduced exchange causes a strong increase of salinity in the Mediterranean in spite of reduced net evaporation.

Simulated climate variability in the region of Rapa Nui during the last millennium

“…The evaluation of a 300-yr control simulation with ECHAM5/MPIOM already showed that the tropical sea surface temperature climatology is well simulated and that global-scale heat and freshwater-transport are in agreement with observations (Jungclaus et al, 2006). Furthermore, ECHAM5/MPIOM has been successfully applied to different paleoclimate states such as Mid-Holocene climate and transient Holocene climate simulations (Fischer and Jungclaus, 2010;Otto et al, 2009;Dallmeyer et al, 2010;Vamborg et al, 2011), Last Glacial Maximum simulations (Mikolajewicz, 2011;Arpe et al, 2011), Eemian climate simulations (Fischer and Jungclaus, 2010;Schurgers et al, 2006) and Eocene climate simulations (Heinemann et al, 2009).…”

The effect of greenhouse gas concentrations and ice sheets on the glacial AMOC in a coupled climate model

“…due to the reduced exchange with the Atlantic (Mikolajewicz, 2011). The eastern North Atlantic shows a salinity increase of about 2.5 g kg −1 which can also be attributed to the shift in the subtropical-subpolar gyre system (Fig.…”

The deglaciation of Sierra Nevada (Spain), synthesis of the knowledge and new contributions

“…However, it is uncertain what happened with the glacier systems between 30 and 20 ka. The permanence of cold temperatures during the final millennia of the last North Atlantic glaciation -also detected in isotopic records of the Mediterranean Sea (Hayes et al, 2005;Mikolajewicz, 2011)-suggests that the glaciers may not have disappeared in this phase, although they did experience minor advances and retreats . In fact, these must have been of less spatial significance than the advance recorded in 19-20 ka BP, close to the maximum extent reached around ten millennia earlier (Gómez- .…”