Weather kite gets second wind
The red kite is now a commonly-seen bird of prey in the skies of the south-east, but a specially designed artificial blue kite promises a new way to make weather measurements.
Writing in the Review of Scientific Instruments, scientists at the University of Reading's Department of Meteorology describe a high-tech kite developed to measure wind speed. Kites have long been used to transport instruments up into the lower atmosphere, but rather than just offering a convenient "sky hook", the new approach uses the kite itself to detect the wind variations.
The wind speed varies the kite line's tension, which can be measured conveniently at the ground, rather than by carrying a sensor up on the kite aloft.
Kieran Walesby, who developed the instrumentation as part of his postgraduate research work at Reading, said: "This technique allows wind speeds above the ground to be measured without the need for a fixed instrument tower, and is therefore very portable."
The kite used in these experiments was specially built in the Department of Meteorology, and was combined with a tension-measuring system optimised to overcome temperature variations during long kite flights. The kite line tension is found by measuring the small distortions generated on a metal ring used to anchor the kite, using a set of miniature strain gauges.
Professor Giles Harrison, Professor of Atmospheric Physics who supervised the work, said: "Benjamin Franklin's 1752 experiment is a famous early example of using a kite to measure atmospheric properties. Our system reasserts the kite's value in atmospheric science, through offering an easily-implemented method for investigating lower atmosphere air flows, such as those which transport pollution."