Paris, July 22: A wind storm that ripped across western China’s Taklimakan desert kicked up hundreds of thousands of tonnes of dust that high-altitude winds then carried around the world in less than two weeks, a study says.
On May 8-9, 2007 winds reaching up to 36km/h blew an estimated 800 000 tonnes of dust into the air, according to satellite imaging and computer models.
Trapped against the high walls of the Tibetan plateau, the dust was forced higher and higher, reaching an altitude of around 5 000 metres.
A warm convection flow then lofted most of the dust higher still, where it caught a jetstream that took it on a “journey around the world” at between 8 000 and 10 000 metres.
After 13 days, the plume passed over the Taklimakan desert where it had begun its strange trek.
On its second trip around the globe, part of the dust fell on the northwest Pacific thanks to an abrupt change in a high-pressure weather system. More may have fallen in the Mid-Atlantic and Balkans.
The cloud was detected by an imager called Caliop, launched in 2006 aboard a Nasa Earth-observation satellite, Calipso.
—Agencies