THE FUTURE OF THE SUN'S ACTIVITY
Data gleaned from hundreds of thousands of images of the Sun, some going back over 100 years, will be combined with powerful modern statistical techniques in a new project aimed at helping scientists understand outbreaks of sunspots, flares and other solar activity. Dr Andrew Conway of the University of Glasgow, who works with Dr Alec MacKinnon at the University of Glasgow and Dr Keith Macpherson at the University of Oxford, will describe this ambitious undertaking at the UK Solar Physics meeting in Guernsey on Tuesday 10th August.
A great variety of activity disturbs the surface of the Sun, and the surrounding solar corona, which becomes visible during a total eclipse. Solar flares release huge amounts of energy in the form of light and high-speed particles. Coronal mass ejections send vast clouds of solar gas out into the solar system, and the Sun becomes peppered with dark regions called sunspots. Such events are related and are all linked to the Sun's magnetic field, which becomes most complex and tangled at solar maxima, roughly every 11 years.
Although astronomers have known for many years that sunspot numbers rise and fall over a period of approximately 11 years, the precise length of the cycle and the maximum numbers of sunspots varies from one cycle to another in a manner that has proved very difficult to forecast. And there are good reasons why it would be very valuable to predict solar activity. The streams of particles reaching the locality of the Earth can disrupt power supplies and endanger operations in space, for example.
In the past, attempts to predict solar activity have mainly used statistical methods, based on past records. For example, a neural network can be trained to predict next month's sunspot number based on the numbers for the last 12 months. But this does not take into account what is known about the physics of the Sun and its active regions.
For the first time, Dr Conway and his colleagues are combining solar physics and statistics. "In a sense it is like a jigsaw puzzle" says Dr Conway. The physics gives us the pieces, telling us how active phenomena like flares and sunspots occur, and how they are related. The statistics tells us how likely it is that one outbreak of activity will cause another one nearby, allowing us to fit the pieces together in the right way to see the whole picture."
"To build up this picture, we need more information than simple counts of the numbers of spots on the Sun at different times. Photographs of the Sun showing sunspots and bright spots have been taken routinely for over one hundred years now, but it is really the more advanced technology of the past few decades that allows us to move beyond just predicting sunspot numbers. Hundreds of thousands of pictures are now at our disposal, some taken from space, including X-ray and radio images. With the power of modern computers, together with the artificial intelligence of modern data processing, it is now possible to explore these images as a whole and see if they can help us understand the Sun's activity, what we can expect of it in the future and, ultimately, its effects on us."
The full text of the talk may be found at: http://www.astro.gla.ac.uk/users/conway/nam99/tal.htmlNOTES
1. The next solar maximum is expected to occur next year (2000). The shape and extent of the solar corona changes through the solar cycle. Near maximum it tends to appear evenly distributed around the Sun. Near solar minimum, there is little corona over the Sun's poles, and its appearance is more like wings on either side.
2. The UK Solar Physics Meeting is being held in parallel with the National Astronomy Meeting at the Beau Sejour Centre, St Peter Port Guernsey, Channel Islands from Tuesday 10th to Friday 13th August. On Wednesday 11th August participants from both meetings will travel to Alderney for the total solar eclipse and no scientific sessions will take place. The meeting press room will not be staffed on that day.
CONTACT DETAILS - DR ANDREW CONWAY
Dr Conway will be at the Guernsey meeting 9 - 13 August and may be contacted via the press room (see below) during this time.
Until the end of August: Dept. of Physics and Astronomy
From 1 September:
CONTACTING THE PRESS ROOM and PRESS OFFICERS AT THE UK SOLAR PHYSICS MEETING AND NATIONAL ASTRONOMY MEETING
Except on Wednesday 11th August, please try press room numbers before calling mobiles.
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