The Engineer

Project studies electrons in the Van Allen radiation belt

News

Scientists at Lancaster University are working with colleagues at the British Antarctic Survey on a £400,000 project to understand how particles from space affect the Earth’s atmosphere.

They aim to find out more about the behaviour of electrons in the Van Allen radiation belt around the Earth, which can damage orbiting satellites and spacecraft.

The Van Allen radiation belt periodically discharges energetic particles such as electrons and ions into the high atmosphere above Earth, especially at the polar regions. This can change the chemistry of the atmosphere, with possible implications for climate change.

Dr Mick Denton from the Space Plasma Environment and Radio Science (SPEARS) group at the Department of Physics at Lancaster University said: ‘It’s still a mystery how much the radiation belt is affecting Earth and how much of an impact it has. We have no clear understanding of what causes the radiation belt to come and go. This is also a serious problem for satellites in orbit that can be damaged by such energetic particles.’

The five-year project will see two radio receivers installed in Antarctica as part of a global network of receivers set up by the AARDDVARK consortium of international universities from Australia to South Africa and Hungary.

Dr Denton said: ‘The receivers will pick up signals broadcast from Very Low Frequency [VLF] transmitters all over the world that transmit over long distances. We’ll be picking up electromagnetic changes to the radio signals caused by the particles entering the atmosphere and from that, we can analyse the data to find out more about their nature.’

The receivers are sited in the Antarctic because the effect of energetic particles on radio waves is enhanced over thick ice sheets.

Dr Mark Clilverd from the British Antarctic Survey said: ‘We know where these electrons hit the atmosphere but don’t know how often they occur, how long they last, or how fast they are travelling. We need to find these things out in order to determine the impact of space particles on the atmosphere. The region of the Antarctic in which we are going to put the instruments is the best place on Earth to make our measurements, but it is also one of the toughest.’

The project complements a NASA mission due to be launched in 2012 called the Radiation Belt Storm Probes, which aims to investigate energetic particles using satellites in space.