08.12.: Jump start for the Gulf current

Geoscientists from Bremen investigate climatic interplay between Atlantic and Indian Ocean

14,700 years ago, Greenland experienced a warming of 9 °C within a couple of decades, the most striking temperature increase in the Northern Hemisphere high latitudes during the entire last deglaciation. The abrupt warming was probably linked to a sudden strengthening of the Atlantic Ocean circulation but the ultimate mechanism responsible therefore is not clearly understood. Chiessi et al. show new geochemical records from the South Atlantic that address this issue. According to the new records, the upper South Atlantic also underwent a strong increase in temperature and salinity synchronous to the temperature change in Greenland. While the warming in the South Atlantic is also a consequence of the strengthening of the Atlantic Ocean circulation, the increase in salinity points to a massive inflow of salty Indian Ocean waters into the Atlantic Ocean. High salinities in the upper Atlantic Ocean have been described as a key condition for a strong Atlantic circulation. Chiessi et al.’s records highlight the crucial role played by Indian-Atlantic interocean exchange as the trigger for the strengthening of the Atlantic circulation and the abrupt warming in the Northern Hemisphere high latitudes 14,700 years ago.

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MARUM aims at unravelling the role of the oceans in the Earth’s system by employing state-of-the-art methods.
It examines the significance of the oceans within the framework of global change, quantifies interactions between the marine geosphere and biosphere, and provides information for a sustainable use of the ocean.

MARUM comprises the DFG research center and the cluster of excellence "The Ocean in the Earth System".