Lo studio approfondito dell’area Mediterranea potrebbe fornire informazioni rilevanti su quello che è accaduto al clima negli ultimi 5 milioni di anni, all’inizio delle delle glaciazioni dell’emisfero settentrionale.

Questo è il tema principale di un articolo scritto dai ricercatori del CMCC Florence Colleoni, Simona Masina, Alessandra Negri e Alice Marzocchi, ora pubblicato nella rivista Earth and Planetary Science Letters con il titolo “Plio–Pleistocene high–low latitude climate interplay: A Mediterranean point of view”.

I risultati della ricerca, sostengono gli autori, confermano che il bacino Mediterraneo è un luogo ideale per lo studio dell’interrelazione su ampie scale temporali tra i climi di alte e basse latitudini.

L’abstract dell’articolo (in inglese)
The high–low latitude climate interplay during the Plio–Pleistocene global cooling is not yet well understood.
Insight on the Mediterranean region can provide some clues about past significant climate changes since the basin reflects the climate dynamics of both high-latitude and low-latitude regions, being connected to the North Atlantic and subjected to monsoon influence. Here we shade light on this connection problem by performing a spectral analysis on an Eastern Mediterranean stack of planktonic records spanning the last 5
Ma and by further comparing it to North Atlantic and Pacific deep- and surface-water records. Our main conclusion is that the Mediterranean detected the main global climate transitions over the last 5 Myr although sapropel depositions indicate that it remained influenced by the African summer monsoon during the whole interval. Our analysis reveals that until 2.2 Ma the Mediterranean planktonic record is driven by regional processes dominated by precession. The progressive emergence of the 41-kyr frequency in the Mediterranean records around 2.8 Ma suggests that, since this date, the Mediterranean was more and more affected by the high-latitude climate dynamics forcing than by the low-latitude one. Moreover, during the ongoing Plio–Pleistocene cooling, the 41-kyr frequency signal in the Mediterranean records anticipated high-latitude deep-water response to the intensification of the Northern Hemisphere Glaciations (NHG) and lagged the signal in tropical latitudes. Finally, toward 1.2 Ma the results suggest that the progressive shift from the 41-kyr to the 100-kyr frequency was led by the northern high latitudes. Overall, our results confirm that the Mediterranean is an ideal site to study the interplay between high and low latitude climates.
La versione integrale del paper si può leggere qui

Image credits: CC from kern.justin at Flickr

Leggi anche su Climate Science and Policy (in inglese):

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• Discovering The Great Warming: Lessons from The Ancient Earth (video), archeologist Brian Fagan,
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