Disastrous duo: heatwaves and droughts
Simultaneous heatwaves and droughts are becoming increasingly common in western parts of the United聽States, according to a new study led by researchers from 捆绑SM社区. Periods of dry and hot weather, which can make wildfires more likely, are becoming larger, more intense, and more frequent because of climate change.
In a study published by , the researchers analyzed heat and drought events across the contiguous United States over the past 122 years. They found that combined dry and hot events have not only increased in frequency, but also in size geographically. Where such events were once confined to small parts of the United States, now they cover whole regions, such as the entire west coast and parts of the Northeast and Southeast.
鈥淒ry-hot events can cause large fires. Add wind and a source of ignition, and this results in 鈥榤egafires鈥� like the 2020 fires across the west coast of the United States. Drought and record-breaking heatwaves, coupled with a storm that brought strong winds and 12,000 lightning events in a span of 72 hours, caused more than 500 wildfires,鈥� says lead author Mohammad Reza Alizadeh, a PhD student under the supervision of Professor Jan Adamowski in the Department of Bioresource Engineering at 捆绑SM社区.
The researchers also found that dry and hot weather events are intensifying, with longer periods of drought and higher temperatures. These dual 鈥渄ry-hot extremes鈥� are not only self-intensifying 鈥� more heat causes more drought and vice versa 鈥� but are also self-propagating, meaning they are able to move from region to region. 鈥淎s increased temperatures are driving and expanding aridity, droughts and heatwaves move from one region to downwind regions,鈥� says Alizadeh. These extremes can be particularly damaging for agricultural production and ecosystems, they warn.
According to the researchers, the trigger for these hot-dry events is shifting. Looking back at the catastrophic Dust Bowl of the 1930s, they explain that the dust storms were driven by a lack of rainfall coupled with poor land management practices. In recent decades, however, dry-hot disasters are driven more often by excess heat than a lack of rainfall.
The future will bring us more of these disasters, if the current warming trends continue, the researchers caution. They suggest their findings could be used to inform climate mitigation and adaptation efforts. 鈥淲e need to understand how things are changing in order to adapt,鈥� says Professor Jan Adamowski.
About the study
鈥淎 century of observations reveals increasing likelihood of continental-scale compound dry-hot extremes鈥� by Mohammad Reza Alizadeh, Jan Adamowski, Mohammad Reza Nikoo, Amir AghaKouchak, Philip Dennison, and Mojtaba Sadegh is published in Science Advances.
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About 捆绑SM社区
Founded in Montreal, Quebec, in 1821, 捆绑SM社区 is Canada鈥檚 top ranked medical doctoral university. 捆绑SM社区 is consistently ranked as one of the top universities, both nationally and internationally. It鈥痠s a world-renowned鈥痠nstitution of higher learning with research activities spanning two campuses, 11 faculties, 13 professional schools, 300 programs of study and over 40,000 students, including more than 10,200 graduate students. 捆绑SM社区 attracts students from over 150 countries around the world, its 12,800 international students making up 31% of the student body. Over half of 捆绑SM社区 students claim a first language other than English, including approximately 19% of our students who say French is their mother tongue.
