Research offers hope in solving polar communication and defence system problem
Release Date 28 March 2013
Cutting edge research into the ionised upper atmosphere above the poles could strengthen countries' defence systems and make communications with aeroplanes and satellites more reliable.
Scientists from the University of Reading and partner institutions¹ have revealed for the first time how polar cap patches impact on communications systems and how a better understanding of ionisation density will help predict and avoid the problems they cause with radar, communication and navigation systems.
Polar cap patches are islands of enhanced ionisation that float over the poles at a height of around 150 miles affecting radio waves. Patches disrupt communications to aeroplanes on transpolar routes, such as between the UK and the west coast of the USA, which requires flights to be re-routed to lower latitudes, costing both time and aviation fuel. They also affect the precision of early warning radar systems used to counteract missile strikes.
Professor Mike Lockwood, from the University's Department of Meteorology, co-authored the study and was the only UK researcher involved in the research: "These findings are a crucial step towards being able to predict when polar cap patches will occur. We know polar ionisation is caused by solar extreme ultra violet radiation from the sun but how it divides into these patches remained a mystery - until now.
"The research shows how large-scale circulation of the ionisation can allow low densities to form on the nightside, away from the ionising solar radiation, but also can interleave them between the high-density patches coming from the dayside.
"It may be that our results are not completely general as we observed patches that formed in the European longitude section, and the offset of the geographic and geomagnetic poles may make the behaviour somewhat different at other longitudes. However, this is an important step towards solving the problems radar, communication and navigation systems experience from polar patches."
The researchers used global positioning system (GPS) satellite transmissions as well as a global network of specialist radars that are positioned in a ring around the Arctic and look north.
"Direct Observations of the Evolution of Polar Cap Ionization Patches" by Zhang et al. will be published in ‘Science' on Friday 29 March.