Researchers hope that their modelling will help decision-makers prepare for changing storm patterns.
21st May 2020
Climate change is influencing the location of tropical cyclones, according to research from the National Oceanic and Atmospheric Administration (NOAA), a US scientific agency within the United States Department of Commerce.
Researchers say that the number of tropical cyclones has been rising since 1980 in the North Atlantic and Central Pacific, while storms have been declining in the western Pacific and in the Indian Ocean. This pattern, the researchers say, can be attributed to three influences: Greenhouse gases are warming the upper atmosphere and the ocean, this combination creates a more stable environment with less chance that convection of air currents will help spawn and build up tropical cyclones. Secondly a decline in particulate pollution, due to pollution control measures, may mean that more sunlight is reaching the oceans and warming them. Finally volcanic eruptions have impacted tropical cyclone locations. Researchers cite the major eruptions in El Chichón, Mexico, in 1982, and Pinatubo, the Philippines in 1991, which led to the atmosphere of the northern hemisphere cooling. This caused tropical cyclone activity to shift southward for a few years. However, since 2000 warming of the ocean has resumed and tropical cyclone activity in the northern hemisphere has increased.
Using modelling, researchers predict that the number of tropical cyclones will decrease as we move toward the end of the 21st century. But those that do happen will be ‘significantly more severe’ due to the rising ocean surface temperature fuelling the intensity and destructiveness of the storms.
Hiroyuki Murakami a climate researcher at NOAA’s Geophysical Fluid Dynamics Laboratory, and lead author of the study, which is published in Proceedings in the National Academy of Sciences said ‘We hope this research provides information to help decision-makers understand the forces driving tropical cyclones patterns and make plans accordingly to protect lives and infrastructures.’
Proceedings in the National Academy of Sciences DOI: 10.1073/pnas.1922500117