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New research suggests that ocean circulation in the North Atlantic is now the lowest in about 1,500 years, which could have a profound impact on future climates in North America and North America. ;Europe. Experts from the Department of Earth Sciences and the Swire Institute of Marine Sciences at the University of Hong Kong issued a dramatic warning after studying the Southern Atlantic Tidal Circulation System (AMOC), which transports water from hot surface towards the Arctic and cold deep waters towards the equator.
Researchers, co-led by Dr. Christelle Not and Dr. Benoit Thibodeau, said current ocean conditions were similar to those that preceded a prolonged cold spell between 1600 and 1850, known as the Little Ice Age.
Winters were extremely cold and summers were often cold and rainy, resulting in many crop failures, famine and population decline.
Social unrest has increased as large sections of the population are reduced to famine and poverty.
Dr. Thibodeau said, "AMOC plays a crucial role in regulating the global climate, but scientists have struggled to find reliable indicators of its intensity in the past.
"The discovery of this new AMOC record will improve our understanding of its factors and ultimately help us better understand the potential changes in the near future in the context of global warming."
Scientists said that heat and energy transfer in the North Atlantic had directly influenced the climate in Europe and North America, but also had an impact on the African and Asian monsoon system because its effects on sea surface temperature and atmospheric circulation.
Many climate models predict a weakening or even collapse of AMOC due to freshwater discharges from the Greenland ice sheet.
Melted ice has a lower density than that of seawater and prevents the formation of deep waters that slow down the flow as a whole.
Dr. Not and Thibodeau used microfossils found in a sediment core where two major currents occur off the coast of Canada to estimate past ocean temperatures.
The strength of these currents will control the temperature of the water at the core site, implying that the temperature reconstructed from this core indicates the strength of the circulation in the North Atlantic.
The scientists validated their findings using instrumental data and two numerical models capable of simulating the climate and the ocean, but acknowledged that there was still work to be done.
Dr. Not says, "Although we can base our 20th Century temperature reconstruction on instrumental measurement, it is impossible to do so for the Little Ice Age. Therefore, we need to do more analysis to consolidate this hypothesis. "
The results were published in the prestigious journal Geophysical Research Letters.
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