资源环境科技发展态势分析平台

Studies show an increasing tendency for tornadoes in the United States to occur in larger outbreaks. To shed light on the reason for this, the authors use a regression model to quantify the relationship between convective environmental variables and accumulated tornado power (ATP). They consider only days with many tornadoes that occur as part of an outbreak. Results show an average upward trend in ATP at 5% ([2.5%, 12%], 95% uncertainty interval) per year. ATP increases by 125% for every 10 m.s(-1) increase in bulk shear (on average)and by 33% for every 1,000 J.kg(-1) increase in convective available potential energy holding the other variables constant. Changes in bulk shear, which has the largest effect on ATP, might help explain the documented changes in tornado activity.