Theme Convener: Arthur Garratt ◦ Display Designer: Ronald Sandiford
Here, on this gallery of the Dome, we follow the story of exploration upward off the earth, first of all into the atmosphere which causes our weather.
Weather records were kept at the Great Exhibition in 1851 and the first daily weather map ever produced was sold to the public there. In the “Sky” section of the Dome a modern Weather Forecasting Unit is working. It produces forecasts for the next twenty-four hours, illustrating at the same time how the meteorologist goes to work.
Modern forecasting depends on the collection of weather data all over the world, and the passing of the information quickly to the central points where the forecasts are made. Our present system is essentially an international one, operating through a world-wide network of radio, telephone and teleprinter services which are in constant use for weather messages only.
Developments in physical appliances have been a great help to meteorologists because they can provide data from places out of man’s reach. Balloons, for instance, are now sent far up into the sky with special equipment that can radio back information about conditions in the upper atmosphere. Meanwhile, their course is plotted by radar to show how the wind is blowing, say, ten miles up.
This is just one example of the sort of equipment that is now being developed so that we can forecast weather more accurately and for longer periods ahead than is possible at present.
From the weather-zone, the story of exploration tends upward to about 250 miles above the earth’s surface. British scientists were among the first to discover that the sun’s radiation forms layers at about this height by electrically charging (or ionising) the particles of the atmosphere. This region is now called the ionosphere, and it has three main layers – one 70 miles up, another at 140 miles and a third 250 miles above the earth.
These layers are the reason why we can transmit radio signals for great distances. But they are not hard and fast in their behaviour, so there are a lot of variations that have to be understood before our long-distance signalling can be perfect.
In this work of improving radio transmission and reception, British scientists and technicians are playing a leading part – just as they did in discovering the ionosphere and exploring it.