Rotor winds can be devastating for aircraft. They form as air is forced over a mountain and then collapses down the other side. These sudden changes - like a wave in the sea - can be very dangerous as atmospheric chemist Dr Jim McQuaid explained: "This circulation literally kills aircraft because it changes direction very quickly. Planes are dragged up and then down, and the shock of this is too much for them."
These winds pose problems for planes landing at airports including Innsbruck in Austria and the Falkland Islands. Better predictions of when these winds form will make landing and taking off in mountainous locations much safer.
Researchers from the Institute for Atmospheric Science, based in the School of Earth and Environment and the UK Met. Office - through the T-REX project - have developed computer models to predict precisely when rotors will form. And a group of them took to the skies over Owen's Valley in the Sierra Nevada in three aircraft - flown by former military test pilots - to check their computer models. Their measurements are now being used not only to check the models' accuracy but to also to improve them.
Dr McQuaid was one of 15 Leeds academics to join the project. He looked at how rotors carry pollutants - and the impact of the rapid changes in altitude on the chemistry of this pollution. He said: "Owen's Valley is instrumented with a vast array of equipment. It's a complex thing as the valley is controlled by a number of different agencies so it's difficult to set-up this scale of project."
The T-REX project is led by Professor Stephen Mobbs - who is also director of the National Centre for Atmospheric Science, funded by the Natural Environment Research Council.
For more information on the research, see:
ncas.nerc.ac.uk/news/stories/trex_june06.asp
www.faam.ac.uk
www.joss.ucar.edu.trex