By Janet Raloff
A large and growing brown cloud of persistent air pollution hovering over northern India and surrounding regions has doubled — and occasionally tripled — the intensity of late spring cyclones in the Arabian Sea during the past three decades.
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Within the past decade, several notable early-season tropical cyclones have ripped through the region. Gonu, the strongest, smashed through the Middle East in 2007, killing dozens and causing more than $4 billion worth of damage. “This supercyclonic storm was Katrina-like in size and intensity,” says climate scientist Amato Evan of the University of Virginia in Charlottesville.
These big storms, which invariably make landfall, represent a new environmental impact that can wreak havoc on people from northern India through the Middle East, Evan and his colleagues propose in the Nov. 3 Nature.