A new study, published in the journal Nature Communications, provides evidence in support of the theory that the closing of the gap between North and South America had led to the evolution of the modern form of Global overturning circulation (GOC) .
- The study has been published by a team of researchers from the Goa-based National Centre for Polar and Ocean Research and the School of Earth, Ocean and Atmospheric Sciences in Goa University.
What is Global overturning circulation (GOC)?
- Global overturning circulation (GOC) is the equatorward transport of cold, deep waters and the poleward transport of warm, near surface waters.
- GOC controls ocean heat distribution and atmospheric carbon dioxide levels, thus playing a critical role in global climate.
- Studies have indicated that tectonically driven changes in the ocean gateways such as the closure of the Central American Seaway (CAS) had a dramatic impact on the circulation.
- CAS is a body of water that once separated North America from South America, since the late Miocene period.
- It is thought that tectonic changes might have led to the formation of two separate water bodies — northern component water in the North Atlantic and Antarctic Bottom Water (AABW) in the Southern Ocean.
- It t is also hypothesised that there would have been large-scale changes in the Deep Water Circulation (DWC) in the oceans across the world, thus impacting global climate through ocean-atmosphere carbon dioxide and heat exchanges.
- The Indian Ocean does not have any major deep-water formations of its own. It acts only as a host for NCW and AABW.
- The northern parts of the Indian Ocean are located at one of the terminal ends of the GOC, far away from the deep-water formation regions and oceanic seaways. These specific features could make the northern Indian Ocean an ideal basin to do this.
(Source: The Hindu)
