A new research by NASA has revealed that extra heat from greenhouse gases were trapped in the Indian and Pacific oceans in recent years and this could likely be the cause of the so -called pause in global warming that was observed over the past decade.
It was observed during the last century that as the concentration of heat-trapping greenhouse gases increase, surface temperatures also increase. The pattern, however, appeared to have temporarily changed in the 21st century with scientists observing that regardless of greenhouse gases continuing to trap extra heat, the average global surface temperature appeared to stop climbing and even slightly cooled for about 10 years.
Researchers of the new study appeared to have found an explanation to this after finding that a specific layer between 100 and 300 meters below the surface of the waters of the Indian and Pacific oceans has been accumulating more heat than previously known.
"We find that cooling in the top 100-meter layer of the Pacific Ocean was mainly compensated by warming in the 100- to 300-meter layer of the Indian and Pacific Oceans in the past decade since 2003," the researchers wrote in their study, which was published in the journal Science on July 9.
By analyzing direct ocean temperature measurements, which included observations from about 3,500 ocean temperature probes called Argo array, the researchers found that the temperatures below the ocean's surface have been rising.
The study found that the Pacific Ocean is the main source of the subsurface warm water but some of these waters have already been pushed to the Indian Ocean. Study author Veronica Nieves, from the University of California, Los Angeles, said that the waters of the western Pacific have become so warm that some of these hot water leaks into the Indian Ocean via the Indonesian archipelago.
The movement of the Pacific's warm water pulled heat away from the surface waters and this led to the abnormally cool surface temperatures observed during the last ten years.
The cooler surface temperatures are also associated with a climatic pattern known as the Pacific Decadal Oscillation that moves in two to three decades cycle. The pattern has been in a cool phase at the time when surface temperatures were cooling. Current signs though indicate that the pattern is being transformed to the opposite phase as the eastern Pacific is observed to having warmer than usual water.
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