Rare earth elements and Nd isotopes as tracers of modern ocean circulation in the central Mediterran

The comprehension of seawater circulation in the central Mediterranean Sea is of great importance to better understand the exchanges of water, heat and chemical compounds between the eastern and western Mediterranean basins and ultimately to the Atlantic Sea. Within the framework of the TIMED and NextData projects, we newly implemented the geochemical tracers of Rare Earth Elements and the isotopic composition of Nd (eNd) in 9 seawater profiles in the central Mediterranean Sea. The distributions of heavy REE and eNd seem to display a conservative behavior explained by mixing of Modified Atlantic Waters, Levantine Intermediate Waters, Eastern Mediterranean Deep Waters (EMDW) and Western Mediterranean Deep Waters. We have introduced these tools in an Optimum Multi-Parameter Analysis together with typical hydrographic variables (potential temperature, salinity and dissolved oxygen). Consistent results of water mass fractions are obtained with some particularities. The most intriguing outcome is the favored detection of EMDW in the Tyrrhenian Sea when considering eNd in the model. This latter finding implies a noticeable deep water flux across the Sicily Strait into the Western Mediterranean that was not clearly evidenced before. 

Ester Garcia-Solsona, Leopoldo D. Pena, Eduardo Paredes, José N. Pérez-Asensio, Lucía Quirós-Collazos, Fabrizio Lirer & Isabel Cacho: Rare earth elements and Nd isotopes as tracers of modern ocean circulation in the central Mediterran, Progress in Oceanography Volume 185, June 2020

Holocene variability in the inflowing North Atlantic waters into the Mediterranean Sea

This manuscript presents a new high resolution Sea Surface Temperature (SST) record from the Alboran Sea that covers whole Holocene and part of the deglaciation and based on Mg/Ca ratios on plankthic foraminifera. Maximum SST were reached in the early Holocene and several millennial scale oscillation occurred but they were particularly intense at the Late Holocene. Theses patterns are associated to changes in the North Atlantic Oceanography and transmitted into the Mediterranean through the inflowing surface waters. 

Català, A., Cacho, I., Frigola, J., Pena, L. D., and Lirer, F.: Holocene hydrography evolution in the Alboran Sea: a multi-record and multi-proxy comparison, Clim. Past, 15, 927–942, 2019.

A new intermediate water mass in the Alboran Sea during late deglacial and early Holocene

This manuscript presents the first evidences for the appearance of a distinctive intermedite water mass in the Alboran Sea during the second phase of the last Organic Rich Layer formation in the Alboran Sea (Younger Dryas and early Holocene period). This is a particular intriguing period in the evolution of the Mediterranean Thermohaline system since major changes occurred in both Mediterranean basins, but not in the same direction. This new described water mass has been identified in base to its relatively high oxygen content, according to the benthic assemblage, and the gradient of carbon isotope ratios measured in different benthic foraminifera species.

Pérez-Asensio, J.N., Frigola, J., Pena, L.D., Sierro, F.J., Reguera, M.I., Rodríguez-Tovar, F.J., Dorador, J., Asioli, A., Kuhlmann, J., Huhn, K., Cacho, I., 2020. Changes in western Mediterranean thermohaline circulation in association with a deglacial Organic Rich Layer formation in the Alboran Sea. Quat. Sci. Rev. 228, 106075.