Eastern Mediterranean water outflow during the Younger Dryas was twice that of the present day

About 13,000 years ago, a climate crisis caused a global drop in temperatures in the northern hemisphere. This episode of intense cold, known as the Younger Dryas, also caused severe aridity across the Mediterranean basin, which had a major impact on terrestrial and marine ecosystems.

But what do we know about the impact of this climate change on water circulation in the Mediterranean?

Through an innovative technique based of neodymium radiogenic isotopes, this new study demonstrates that the flow of water masses from the eastern Mediterranean to the Atlantic Ocean during the Younger Dryas doubled the actual flow. Such situation would have implied an injection of salt into the North Atlantic, just when its circulation was slowing down, thus, contributing to the reactivation its circulation, that led to a rapid warming in Europe and the Mediterranean region.

Our study is of great relevance since a reduction of the North Atlantic circulation is expected in the next few years due to the global warming. This situation could be comparable to that of the Younger-Dryas where a significant reduction of rainfall in the Mediterranean occurred. In this context, our work reveals that the increase in aridity expected by the end of the century could intensify the Mediterranean circulation, but is unknown if the temperature increase could counteract this effect.

Study published in Nature's Communications Earth and Environment journal as Trias-Navarro, S.; Pena, L.D.; de la Fuente, M.; Paredes, E.; Garcia-Solsona, E.; Frigola, J.; Català, A.; Caruso, A.; Lirer, F.; Haghipour, N.; Noel Pérez-Asensio, J.; Cacho, I. “Eastern Mediterranean water outflow during the Younger Dryas was twice that of the present day”. Communications Earth & Environment, April 2023. Doi: /10.1038/s43247-023-00812-7

News UB

Earth & Environment

Behind the Paper

TRANSMOW campaign to analyse circulation of Mediterranean outflow waters with new geochemical tracer

Finding the signature of past climate transitions in the Mediterranean using the analysis of innovative geochemical tracers –specifically, isotopes of neodymium and rare-earth distribution– is the objective of the oceanographic campaign TRANSMOW, led by the experts Leopoldo Pena and Jaime Frigola, members of the consolidated Research Group on Marine Geosciences of the Faculty of Earth Sciences of the UB.

The Mediterranean outflow waters is a constant and strong current of warm and saline water masses moving towards the Atlantic Ocean. The properties of this hydrographic connection between both marine basins through the ocean corridor of the Gibraltar Strait are marked by the climate conditions of the Mediterranean region. Nowadays, determining the potential impact of the Mediterranean water mass on the thermo-haline Atlantic circulation system –and ultimately, on the global climatology and oceanography– is still a topic under debate in the scientific community.

TRANSMOW will describe the Mediterranean outflow waters and the circulation flow around the Iberian Peninsula with an innovative methodology. “For the first time, we will apply the analysis of innovative chemical tracers –in particular, isotopes of neodymium and rare-earth elements– to improve the estimation of the MOW mix with Atlantic surrounding waters”, notes Isabel Cacho, professor at the Department of Earth and Ocean Dynamics of the UB, and principal researcher of the projects framed within this oceanographic campaign.

UB News

Persistent warm Mediterranean surface waters during the Roman period

The greatest time of the Roman Empire coincided with the warmest period of the last 2,000 years in the Mediterranean, according to a study published in the journal Scientific Reports, from the Nature group. The climate conditions derived progressively towards arid conditions and later colder ones coinciding with the historical fall of the empire

The study identifies for the first time a warming phase which is different during the Roman period in the Mediterranean area and is focused on the reconstruction of the sea surface temperature (SST) over the last 5,000 years.These new records were correlated to data from other areas of the Mediterranean (Alboran Sea, Menorca basin and Aegean Sea) to show a regional signal of the basin to identify the Roman period (1-500 AC) as the warmest period of the last 2,000 years, 2ºC warmer than the average values at the end of the century. The experts also comment on the impact of the rainfall regime during this period –marked by a great regional variation of the most wet and arid phases- in the evolution of the Roman Empire

Click Me