Events that deliver about half of global rainfall are getting shorter but more intense, carrying wide-ranging implications for weather patterns worldwide. A new study shows that these intense downpours have become fewer in number and shorter in duration, compressing identical amounts of rain into quicker and more extreme events.
Study Findings and Global Rainfall Data
Chiyuan Miao and colleagues from Beijing Normal University in China examined daily measurements recorded between 1980 and 2022 using more than 19,000 rain gauges globally. The researchers discovered that an average of roughly half of the total global rainfall occurred during approximately nine multi-day storms, spread over a cumulative period of about 28 days.
However, the analysis revealed that the average length of an intense storm has decreased by about 86 minutes per decade since 1980. This reduction cuts the overall time required to deliver half of the world’s annual rainfall by just over 9.5 hours.
Regional Impacts and Risks
The research, published in Earth’s Future, indicates that these shifts are occurring across every continent, though regional variations exist. Europe and South America experienced the highest rates of storm compression, with the wettest storms shortening by up to 144 minutes a decade.
These atmospheric changes will cause regional consequences that include altered drought risks, flash flooding, water security challenges, farm productivity shifts, soil erosion, and changing susceptibility to wildfires.
