Few sciences have become as complex as meteorology, or developed so fast from such humble beginnings. Illiterate sailors once learned basic rhymes to help them remember what weather might follow certain cloud formations. 'Red sky at night sailors' delight, red sky at morning, sailors' warning' was almost as elaborate as it got. "Mackerel skies and mare's tails, wise sailors furl their sails,' told of storms that were likely to follow high cirrus clouds but at that time even the term 'cirrus' would not have been recognised, for clouds had not yet been classified.
Today, meteorological equipment embraces ocean buoys and satellites, Antarctic stations and more. One of the newer technologies is radar. Developed in World War II to detect incoming aircraft, it can now be used in the lower atmosphere to detect changes in humidity and temperature.
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"These changes appear as 'targets' which move with the background wind, and effectively trace its path," said Dr Iain Reid, Associate Dean for Commercialization in the Science Faculty. "By measuring the movement of these targets, wind speed and direction can be determined," he said.
Dr Reid is one of the physics department's team which has developed the technology, and he is now a Director of Atrad.
"Turbulence also produces changes in temperature and humidity," said Dr Reid, "And radar can measure the strength and location of this turbulence as well. Depending on the power and frequency of the radar used, information about wind speed, direction and turbulence can be obtained from the ground up to about 100 kilometres," he said.
At about half that height, the sun ionises the atmosphere, separating electrons from their host atoms. Radar can also detect these electrons, and use them as tracers of atmospheric movements.
Meteorological radar is generally used in weather-watching; scanning horizontally to detect precipitation such as rain or snow over a large region. The kind developed at Adelaide University produces a vertical profile of the wind directly above the radar, information that has traditionally been gathered by instruments launched on balloons as often as four times each day. The information is then fed into numerical computer models and used to predict weather patterns.
Atrad has commercialised several types of radar developed by the department's atmospheric physics group. The Japanese Aeronautical Laboratory is acquiring one to be used in flight trials of a model supersonic transport aircraft at Woomera. The radar will measure the vertical wind to determine the most suitable launch time. Later, it will help to verify the plane's flight performance.
Atrad will also supply a very powerful VHF radar to Wuhan University in China. Ranked among the world's top facilities in terms of capability, it will assist research of a similar calibre.
"China is investing in Science and Technology in an attempt to bring themselves up to world standards in several areas," said Dr Reid. "There are perhaps only three other radars in the world with comparable ability," he said. "Atrad has been providing various kinds of radars for years. It is a science-driven company, and its reputation has grown steadily."
Another of the company's radars is destined for weather forecasting in the UK meteorological office. It will replace a balloon station in northern Scotland, where severe weather frequently tracks over the UK and into mainland Europe.
Photo available at: http://www.adelaide.edu.au/pr/media/photos/2001/
Contact: Iain Reid ph: (08) 8303 5042; email: ireid@physics@adelaide.edu.au