Underground Secrets of the Upper Atmosphere

UK scientists in a disused iron mine in Minnesota have discovered that cosmic rays can detect sudden changes in the upper atmosphere.

These changes, where temperatures rise drastically, affect the severity of northern hemisphere winters and the amount of ozone over the poles. It is the first time the connection has been made and it will help improve climate observations.

The findings resulted from STFC scientists and the UK’s National Centre for Atmospheric Science working on a US-led experiment called MINOS (Main Injection Neutrino Oscillation Search).

The main aim of MINOS was to study subatomic particles called neutrinos but the facility also examined cosmic ray showers. The UK team analysed cosmic ray data collected from 2003 to 2007 and their research showed that the number of highenergy rays reaching an underground detector matched temperature measurements in the stratosphere.

MINOS

It’s unusual enough to be sitting half a mile underground doing particle physics, but “It's even better to know that from down there, we can also monitor a part of the atmosphere that is otherwise quite tricky to measure” said Dr Giles Barr, from theUniversity of Oxford and co-author of the study.

Scientists at MINOS study neutrinos produced by the Fermi National Accelerator Laboratory near Chicago. These neutrinos travel through the Earth to the Soudan Mine 450 miles away and are often called ‘ghost particles’ because they rarely interact with matter.

Neutrinos are thought to have played a key role during the creation of the Universe. There are three types or flavours – muon, tau and electron – and they can transform or oscillate from one flavour to another.

• Neutrino research relates to the creation of the Universe
• Cosmic ray data helps improve climate observations
• Fundamental research produces unexpected benefits across other scientific disciplines