Increased warming from changing ocean currents has accelerated over the past 100 years and could ultimately affect climate patterns over much of the world, according to research by two Texas A&M University oceanographers.
Ping Chang and Benjamin Giese, professors in the Department of Oceanography at Texas A&M, are part of a team that analyzed ocean temperature and current data since 1900. Their work is part of a multinational team that included researchers from the Ocean University of China, NOAA, the University of Hawaii, the University of Colorado, the Woods Hole Oceanographic Institution, the University of Tokyo, the Ocean University of China and scientists in Germany and Australia. Results of the team’s study have been published in the journal Nature Climate Science.
The Texas A&M research team found that parts of the world’s oceans are warming at an accelerated rate, showing a global warming “signature” in the ocean. The warming trend in some parts of the oceans is twice as large as the global average, the researchers have discovered.
“Certain parts of the oceans are getting warmer much faster than others,” Giese explains, “and it shows that there are significant regional differences in warming. The difference is from 0.5 to more than 1.5 degrees, and while that may seem small, it is a large change compared with the historical data over the past 100 years.”
Chang says the rising temperatures are possibly attributed to ocean circulation changes, which are likely caused by changes in atmospheric circulation, especially in the winds over the oceans.
“If this trend continues,” he says, “it could have a potential impact on the occurrence of extreme climate events, such as winter storms, in these regions because the atmospheric circulation is affected by sea-surface temperatures. These changes in ocean circulation could also have an impact on marine ecosystems.”
They say that the most severely affected areas of rising ocean temperatures are off the coast of Australia, near the Philippines, the Gulf Stream from Florida to New England, the Brazil current and the Kuroshio current, which is similar to the Gulf Stream but located in the Pacific Ocean near Japan.
The two Texas A&M researchers say the rising temperatures would probably not affect conditions of an El Niño or La Niña event.
“It is difficult to determine how these changes will affect global weather patterns,” Chang explains, “and it is more likely that regional climate extremes will be affected by these rising temperatures.”
The warming trend could pose problems for sensitive marine areas, Giese notes.
“People in Australia are worried about it because it could have an impact on its Great Barrier Reef,” he notes. “Any rise in temperature might damage the sensitive ecosystems of the reef.” At 1,800 miles long, the Great Barrier Reef is so large it can be seen from space.
The team’s work was funded by the China National Key Basic Research Project, the Australian Climate Change Science Program, the Southeast Australia Climate Initiative, the Japanese Ministry of Education, Culture, Sports, Science and Technology, NOAA (National Oceanic and Atmospheric Administration) and the National Science Foundation.