A new study to be published in the journal Nature shows just why the Atlantic Ocean reversed its circulation some 20,000 years ago. Led by two researchers from the Universitat Autònoma de Barcelona the research demonstrates the impact climate change can have on such a large body of water as the Atlantic Ocean.
The Atlantic Ocean circulation is important in ensuring the stability of our planets climate. Warm currents such as the Gulf Stream bring warm water from the tropics to the subpolar regions of the ocean which impact the weather in those regions. Upon arrival these waters sink, taking with them carbon from the atmosphere, and storing it deep below the surface. The colder water then transfers back to the tropical regions and the circulation starts again.
The focus of the research was the role played by the Atlantic in the past.
By investigating the distribution of isotopes in the Atlantic Ocean the researchers were able to study the seafloor sediments 2.5 kilometres deep in the South Atlantic.
The study showed that the circulation in the Atlantic Ocean was substantially different 20,000 years ago, the last planetary ice age.
The balance of seawater to freshwater was significantly different, similar to what many are predicting could occur within the next century if the ice caps and polar ice sheets continue to melt at their current rate. A shift in the overturn of waters could reverse, having implications for weather all across the globe.