World - Unlocking Climate Secrets: How Ocean Salt Patterns Influence Global Weather
A new study reveals the critical role of oceanic salt distribution in regulating global climate, linking historical cooling periods such as the Little Ice Age to changes in ocean salinity and circulation.
This research emphasizes the interconnectedness of tropical and subpolar regions and the importance of salt movement in maintaining the climate stability of the Northern Hemisphere.
The study examines the connection between salinity, ocean currents, and climate.
Researchers from Dalhousie University in Canada, GEOMAR Helmholtz Centre for Ocean Research Kiel, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI), and MARUM – Center for Marine Environmental Sciences at the University of Bremen have uncovered the vital role that the distribution of salt by ocean currents plays in regulating the global climate.
Their new study has delved into natural climate anomalies, such as the Little Ice Age, a period from the 15th to the mid-19th century that led to harsh consequences like poor harvests, famine, and disease in Europe. Although this period is well-researched, the underlying climatic mechanisms behind it are still subject to debate.
“Looking at recent, natural climate anomalies helps to understand the processes and mechanisms that human-induced global warming may trigger,” says Dr Anastasia Zhuravleva, lead author of the study. She was a PhD student at GEOMAR and received the Annette Barthelt Prize for her dissertation in 2019. She then worked as a post-doctoral researcher at GEOMAR and Dalhousie University, where the study was completed.
Importance of the Tropical Atlantic
“Researchers often consider an increase in sea ice extent and desalination in the subpolar North Atlantic as possible triggers for past cold periods, but processes in the tropical Atlantic appear to be equally important,” says Dr Zhuravleva. “In fact, in contrast to the northern and mid-latitudes, there is little information on these recent climate events from the subtropical-tropical Atlantic and their impact on regions in the Northern Hemisphere,” adds Dr Henning Bauch, paleoclimatologist at AWI and GEOMAR, co-initiator and co-author of the study. “This is where our research comes in.”
So, what happened in the tropical Atlantic during historical climate anomalies, and how might potential changes there have affected ocean circulation and climate much further north? To answer these questions, the team worked on a sediment profile from the southern Caribbean and reconstructed the salinity and temperature of the surface water over the last 1700 years. Among other things, the researchers determined the isotopic and elemental composition of the calcareous shells of plankton.
