Scientists at the Massachusetts Institute of Technology have confirmed that hurricanes in the North Atlantic have intensified over the past 150 years. However, this trend is not observed in the rest of the world. This is reported in an article published in the journal Nature Communications. The scientific work is briefly described in a press release on Phys.org.
Researchers have created climate models to reconstruct the frequency and intensity of hurricanes and tropical cyclones around the world over the past several centuries. The results confirmed the historical record that there has been a general increase in storm activity in the North Atlantic over the past 150 years.
The most complete record of tropical cyclones is collected in the IBTrACS (International Best Track Archive for Climate Stewardship) database. It includes modern measurements from satellites and aircraft dating back to the 1940s. Older records are based on reports from ships and islands that hit hurricanes and date back to 1851.
Scientists first created a digital map of reconstructed sea routes in the Atlantic and the trajectories of modern hurricanes. The researchers then calculated the likelihood that the ship would hit or miss a hurricane. It turned out that a significant number of early storms were probably overlooked in historical records. Thus, there is a high probability that storm activity has not changed over the past 150 years. However, these results do not take into account the possibility of changing hurricane trajectories.
In the new study, scientists have created three different climate models in the past, combining it with a hurricane model that tracks the development of tropical storms and their trajectories. All models showed a clear increase in hurricanes in the North Atlantic as early as 150 years ago. In addition, the results revealed a “hurricane drought” in the 1970s and 1980s, when the number of storms decreased. Scientists attribute this to the cooling of the Atlantic due to sulfate aerosols as products of the combustion of fossil fuels. However, the reasons for the increased activity of hurricanes are still unknown.