The last three decades have seen a rise in the number and intensity of tropical cyclones hitting East Asia. A new study suggests that sea surface temperature changes over the Pacific and changing atmospheric circulation patterns might be driving these cyclones.
Also, the number of cyclones hitting the region might increase in the future.
China, Korea and Japan have faced many high-intensity cyclones in the past thirty years. According to the researchers, changes in surface temperatures and shifts in wind flow over coastal regions might be behind the severity of the cyclones. Variations in wind patterns give the cyclones more energy by the time they hit north-east coast of Asia.
For the study, researchers looked into information from five separate data sets that had documented the growth of cyclones across north-west Pacific from 1977 to 2010.
In countries like Taiwan and Vietnam, there was no increase in intensity of the storms. But, the cyclones were generated very close to the land, which helped them gather more energy and move more quickly.
Also, the western Pacific has gotten quite warm in the past thirty years. Other studies, too, have reported a link between climate change and increase in the number of hurricanes.
A related research, published recently in Nature Climate Change, had reported that climate change may lead to Hawaii experiencing frequent hurricanes in the future.
According to the present study, higher sea surface temperatures in Pacific leads to the strengthening of "Walker circulation, which is an ocean-based atmospheric circulation system existing over the Pacific."
Walker circulation gains energy due to the rising difference between warmer western Pacific and the colder central-eastern Pacific.
The changes in wind patterns push the tropical cyclones over north-east Asia. Human-induced climate change is likely to increase number of high-intensity cyclones hitting many regions along East Asia, researchers said.
"Noticeable increases of greenhouse gases over the globe could influence rising sea surface temperature and change large-scale atmospheric circulation in the western North Pacific, which could enhance the intensity of tropical cyclones hitting land over East Asia," Chang-Hoi Ho, from Seoul National University said in a news release.
"If the past changes of large-scale environments are evidence or a result of global warming, it can be assumed that, in the future, more catastrophic tropical cyclones will strike East Asia than ever before," Chang-Hoi Ho added.
The study is published in the journal Environmental Research Letters.